UA-UAKnbitu ojj .aiSLXm(yv>3 Wl aflLrdUi^-vQ^ A^^Cgtiiaq MJjci. />ig.. 97J4 ^,M^ DATE DUE NW**f W*"*** 1 ALBE] RETUF RT R. M^ ITHAO IN TO ySTN LIB] ^. N. Y. RARY ,. ,iM<_ QL 368.G8kT5 ""'""'"'"■"'^'"y 3 1924 002 828 774 K :#i Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924002828774 STU m ES Olsf gIeCMRIKES ■IhclH^ing DfegGriptiohs of 'I^vvqia^v-OQfr'K^ aii^ "a Synopsis of tke Ikigregarine ; !Reecffds ',f|om th^ Mwriapo^ii CioleOpt:era"^'4 : Orthciptera ^^| thie W6rl^| ; WITH FIFTE:^ PtATES BY .%I^pIE■i||^il^^H. wfec)?j. ',/; ;,-;:; . . ^, THESIS :; J. . , .^ :.> ^;,,;". i^ijbmitted in P^ttial Fulfitlifepent of th€jt^tq.uirementVvfw^=t^^^^^^ V' De^ee of fioctojCofvPhilosbplii^y m ^^ --• \;'''S\'<;}ic(^#a)fe Si^O!^l.^of t^* .. ■;\:tiis^®f^i:y:-o|^!llimois; '''/., , ,';;;,,» >-*'■' 'Z^' STUDIES ON GREGARINES Including Descriptions of Twenty-one New Species and, a Synopsis of the Eugregarine Records from the Myriapoda, Coleoptera and Orthoptera of the World WITH FIFTEEN PLATES BY MINNIE ELIZABETH WATSON Ko-^^ Contributions from the Zoological Laboratory of the University of Illinois under the direction of Henry B. Ward No. 65 \5U^']o°\ VITA , Minnie Elizabeth Watson was born December 8, 1886, at Fostoria, Michigan. She attended the graded and high schools of this village and. also the high school at Flint, Michigan, graduating from the latter insti- tution in 1903. She entered Olivet College in 1906 and graduated in 1909 with the degree of A. B. She then taught in the high schools of Eockville Centre and Oyster Bay, Long Island, New York, for three years. The summer of 1910 was spent in graduate work at Middlebury College (Vermont). In 1912-13 she was Assistant in Zoology in the University of Illinois, taking the M. S. degree in 1913. The summers of 1911, 1912, 1913, and 1914 were spent in work"^ at the Biological Laboratory of the Brooklyn Institute at Cold Spring Harbor, Long Island. During the years of 1913-1914 and 1914-1915 she has been a Fellow in Zoology in the University of Illinois. During the period of graduate study she published the following papers : Some New Gregarine Parasites from Arthropoda. Journal of Para- sitology, Volume II, pages 27-36 ; 2 plates. Three New Gregarines from Marine Crustacea. Journal of Para- sitology, Volume II, pages 129-186 ; 1 plate. THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Zoology in the Graduate School of the University of Illinois 1915 TABLE OF CONTENTS INTRODUCTION page Technic 7 Previous Work on Gregarines 9 List of Terms Used in Describing Gregarines..... 10 PART I BIOLOGY The Hosts Infected 12 Localities Represented 14 Seat of Infection 14 Seasonal Variation within the Host 15 Relation of Parasite to Host Tissue 16 Movement in Gregarines , 20 Summary 20 PART II MORPHOLOGY OF GREGARINES Morphology of the Sporonts 27 The Stenophoridae 27 The Gregarinidae 30 Life History of a Typical Cephaline Gregarine 32 The Question of Sporont Maturity 33 The Cysts _ _ 34 Cyst Formation in the Gregarinidae Leidyana erratica 34 Cyst Development and Dehiscence 36 PART III SYNOPSIS OF THE EUGREGARINE RECORDS OF THE MYRIAPODA, COLEOPTERA, AND ORTHOPTERA OF THE WORLD Introduction 40 Brief Synopsis of the Families and Genera of the Tribe Cephalina (Delage) of the Suborder Eugregarinae (Leger) 43 Genera of Uncertain Position 48 Polycystid Gregarines in the Diplopoda 48 Polycystid Gregarines in the Chilopoda „... 80 Polycystid Gregarines in the Orthoptera 94 Polycystid Gregarines in the Coleoptera 128 Appendix An Unnamed Didymophes from a Japanese Beetle 198 6 ILLINOIS BIOLOGICAL MONOGRAPHS [216 PART IV THE CEPH ALINE GREGARINES OF THE WORLD TO- GETHER WITH THEIR HOSTS 200 HOSTS WITH THEIR CEPHALINE GRECARINE PARA- SITES „ 207 List of New Species 215 BIBLIOGRAPHY „ 216 EXPLANA TION OF PLA TES 221 INDEX _ 251 217] STUDIES ON GREGARINES— WATSON INTRODUCTION The following pages contain results from the study of a number of species of gregarines found as parasites in various Orthoptera, Coleop- tera, and Myriapoda during the past three years. The work was done chiefly in the zoological research laboratory of the University of Illinois, under the supervision of Professor Henry B. Ward. I am deeply in- debted to Professor Ward for his direction and helpful suggestions throughout. Four of the species described were found and studied at the Biological Laboratory of the Brooklyn Institute, Cold Spring Har- bor, Long Island, N. Y., and I wish to express my gratitude to Dr. C. B. Davenport for the opportunity of carrying on investigations at the Sta- tion. I wish also to thank Professor F. D. Barker, Professor H. B. Ba- ker, and Mr. Elmer Shafer for kindly sending me material from which parasites were obtained. The gregarines were studied in order to procure data in addition to that already known concerning (1) their biology including the habitat, relation to the host, seasonal distribution, and character of movement, (2) their modes of reproduction, and (3) their systematic position; twenty-two species are described for the first time while additional data is given fof many more species. One result of the work was the compila- tion of a synopsis wherein are recorded in concise form the known facts concerning all the polycystid gregarines which literature records from the Orthoptera, Coleoptera, and Myriapoda of the world. A list was made of all the polcystid gregarines known, with their hosts, in order that species may not be recorded as new which have hitherto been discov- ered and that new species may not be given names which have already been used. TECHNIC The following method was used in studying the live parasites : The anterior and posterior extremities of the host are clipped off as close to the ends of the animal as possible and the alimentary tract is drawn out intact. It is then slit lengthwise with fine scissors, placed flat on a slide, and the masses of food and the parasites then teased out carefully to form a layer as thin and as nearly transparent as possible. Distilled water and normal salt solution were found to be the best media in which to observe the live gregarines. Plasmolysis is slower with S ILLINOIS BIOLOGICAL MONOGRAPHS. [218 the former, while the parasites remain motile longer in the latter. A minimum amount of water or salt solution is used and a cover slip placed over the material to prevent rapid evaporation. The animals are now in an unnatural medium and will disintegrate rather rapidly, so sketches of those which are to be measured must be made with the camera lucida as soon as possible, using a minimum amount of light and a power of the miscroscope of about 100 diameters. When the parasites are nearly transparent, as are those of the species inhabiting the Coccinellidse, e. g., a drop of iodine-iodide solution will turn them brown and thus render them visible; a weak saffranin solution serves to bring out in vivo the nucleus and sometimes the longitudinal striations. Although the parasites are best studied alive, some stained prepara- tions are valuable. In order to preserve parasites in toto for future study, the intestine of the host is slit lengthwise and teased apart gently to loosen the food masses and the parasites. It is then dropped into the fixing solution and agitated gently when the free parasites will drop to the bottom of the dish. The best fixing agent is corrosive-sublimate solu- tion to which has been added a trace of acetic acid; the precipitate is first washed with 50% alcohol and iodine, then with 70% and iodine, and the parasites preserved in 70% alcohol until needed. Picro-formol after Bouin was used in some instances with good results. For staining in toto, two methods are advisable. The slide may be smeared with a very small amount of egg albumen, the animals dropped upon it from a capillary pipette and the preparation placed horizontally in a dish of 35% alcohol for about two minutes to coagulate the albu- men. It may then be carried very gradually down the alcohols to a water solution of Ehrlich's hematoxylin or to a rather weak alcoholic so- lution of borax-carmine and in the latter instance counter-stained with picric acid. The alcohols and stains should be placed in flat dishes so that the slide may be kept horizontal and gradualy immersed and with- drawn from each solution to insure against loss of the parasites. Many grades of alcohol should be used and the parasites kept in each alcohol about fifteen minutes. If the material is abundant, the parasites may be stained en masse in a small dish, since they settle to the bottom, but there is always con- siderable loss in the transfer of liquids. When material is very scarce and all of the parasites must be kept, it is best to preserve simply in glycerine. Parasites from one host intes- tine can be placed on several slides. A weak mixture is made of glycer- ine and water and a very little of this used, the parasites being under ob- servation under the microscope the while, for it is very easy to add too much glycerine and in an instant destroy all the material. The water is very gradually withdrawn by adding a little glycerine for several sue- 219] STUDIES ON GREG ARINES— WATSON 9 cessive days. A little safranin, erythrosin, or other stain may be added to the mixture and will be taken up by the parasites. The colored solu- tion can be removed from the slide as the glycerine applications are made stronger. The study of totos should be supplemented as far as possible with sections. In the instance of the small species not visible to the eye, sec- tions afford the only means of studying the exact location in the host. The whole alimentary tract is fixed and sectioned intact. Sections must be cut very thin, about two micra for the smaller species. Ehrlich's hematoxylin has been found the most satisfactory stain ; it may be used alone or counter-stained with either erythrosin or eosin. Sections reveal the relation of the young parasite to the host cell, whether attached by an epimerite or intercellular, the position of the free sporonts in relation to the cell walls, and various points in structure of the sporonts. By means of sections the position of the sporont can be determined, whether inside or outside of the alimentary tract or its appendages. If the parasite is able to bore through the walls of the intestine into the coelom, the actual burrowing process is often depicted in a series of sections; whether the pyloric cseeca are a seat of infection is also revealed in this manner. PREVIOUS WORK ON GREGARINES In 1903 Minchin adequately summarized the history of gregarines from the time of Redi, who in 1708 recorded the discovery of what was possibly a gregarine, through Dufour, who gave in 1828 the first authen- tic account of these forms and named the genus which he found Grega- rina, up to the beginning of the present century. Other historians of the gregarines have been Lankester, in 1863, Butschli, in 1882, and Leger, in 1892. Like all groups of which little is known, much of the literature of the gregarines is purely systematic in character. Since Minchin 's synop- sis was written in 1903, as well as previously, work on the gregarines has been chiefly systematic. Many new species, a dozen new genera, and a very few new families have been named in the last decade. The suborder Schizogregarinse (Minchin) has received considerable attention from such workers as Leger and Duboscq, Fantham, Siedlecki, Dogeil, and Brasil, and they have described many new species from Crustace^, tra- cheate Arthropoda and Holothuroidea. A few new species have been de- scribed among the Eugregarinse by European and South American work- ers, and in the United States Crawley, Hall, and Ellis have contributed considerable data concerning new species, all those in the last named country being parasitic in tracheate Arthropoda. 10 ILLINOIS BIOLOGICAL MONOGRAPHS [220 Liihe (1903) and Sokolow (1911 and 1912) have given particular attention to the physiology, morphology and reproduction of gregarines in general. A LIST OF TERMS USED IN DESCRIBING GREGARINES Association: The group formed by the attachment of two or more sporonts. Biassociative : The adjective referring to an association of two sporonts attached by unlike ends. Cephaline gregarine: One which possesses an epimerite at some stage in its life history. Cephalont: A term applied to the young gregarine with an epimerite. Cyst : The structureless covering secreted by the associated sporonts at the beginning of reproduction. Deutomerite : The portion of a sporont which is preceded by the septum. Ectoplasm: The outer zone of the body comprising the epicyte, sarco- cyte and myocyte. Endoplasm : The granular protoplasm found within the ectoplasm. Epicyte : The thin, fragile, external layer of the ectoplasm. Epimerite: The temporary or rarely permanent structure at the ante- rior end of the protomerite by which the young parasite is attached to the host cell. It is derived from the epicyte. Isogametes: Gametes which are morphologically identical. Present in most gregarines. Karyosome: A chromatic mass surrounded by plastin and contained within the nucleus. The young individuals possess a single karyo- some which often buds off others as the animals increase in size. Longitudinal striations : The very delicate ridges which are on the out- side of the epicyte. Myocyte: An hypothetical ectoplasmic layer consisting of the myo- nemes. Myonemes: The network of contracile fibrillse embedded in the peri- phery of the endocyte and running around the animal crosswise. They produce movement. Octozoic Spore : A spore containing eight sporozoites. Polycystid : A term applied to gregarines possessing a septum which di- vides the endocyte into regions. Infrequently more than one sep- tum is present. Primite : The first individual in an association of two or more sporonts. Protomerite : The portion of a sporont which precedes the septum. Pseudocyst: The residual protoplasm which after the spores are sepa- rated acquires a membranous wall, swells until the true cyst-wall bursts and allows the extrusion of the ripe spores. 221] STUDIES ON GREGARINES— WATSON 11 Sarocyte : A middle layer of the ectoplasm. Satellite: Any sporont in an association which is attached behind the primite. Generally there is but one, but sometimes several are at- tached in a cluster to the posterior end of the primite or, more gen- erally, arranged linearly one behind the other. Septum : The thin layer of sarocyte which separates the two portions of the sporont, the protomerite and the deutomerite. Spore : The body into which the zygote develops after the acquisition of a resistant outer coating. Spore duct: A tubular outgrowth from the cyst through which the spores are exuded when ripe. Sporocyst : The covering or coverings of the spote. Sporont : An adult gregarine living free in a cavity and deprived of its epimerite, Sporozoite : One of the eight, more or less, small falciform bodies which are released when the spore walls are absorbed. Trophozoite: The young parasite which is either entirely intercellular or attached to an epithelial cell of the host by an epimerite. Synony- mous with cephalont. Zygote: The body formed from the union of two gametes. 12 ILLINOIS BIOLOGICAL MONOGRAPHS [222 Paet I BIOLOGY THE HOSTS INPECTKD Gregarines infect only invertebrates and they have been reported from the following phyla: Coelenterata, Eehinodermata, Platyhelmin- thes, Coelhelminthes (Archianellidae, Gephyrea, Hirudinea, Annelida Polychseta and Oligochaeta), Arthropoda, (Crustacea, Onyeophora, My- riapoda, Hexapoda, and Arachnida), MoUusea and Chordata (Enter- opneusta and Tunicata). Thus far the only groups below the verte- brates from which gregarines have not been reported are the phyla Eoti- fera, Porifera, and Protozoa, and the sub-phylum Leptocardii. Partial List of Animals Examined for Gregarines Number examined Number parasitized o o 2 6 o 2 20 25 o o o Myriapoda Scutigera sp. 10 Scolopendra sp. 5 Scolopocryptops sexspinosus 10 Lithobius sp. 15 Geophilus sp. 15 Euryurus erythropygus 2 Callipus lactarius 24 Parajulus impressus 30 Polydesmus virginiensis 6 Spiribolus marginatus 6 Julus sp. 10 Hemiptera Reduvius sp. 10 Many unidentified Diptera Musca domes tica 10 Unidentified larvae 50 Neuroptera Damsel fly larvae 15 Dragon fly larvae 30 Lepidoptera Many unidentified larvae 223] STUDIES ON GREGARINES— WATSON 13 Partial List of Animals Examined for Gregarines Number examined Number parasitized Mollusca Venus mercenaria lo o Mactra solidissima 5 o Mya arenaria lo o Myiilus edulis S o Modiola sp. S o Pecten irradiens lo o Ostrea virginica '15 o Crustacea Porcellio sp. 8 o Oniscus asellits 30 o Talorchestia longicornis 500 200 Orchestia agilis So 2 Orchestia palustris 10 o Balanus eburneus 5 o Balanus balanoides 50 o Panopeus sayii 10 o Eupagums bernhardi 25 o Uca pugilator 50 40 Uca pugnax 20 15 Cancer irroratus 4 o Platyonichus sp. 4 o Libinia dubia X Libinia emarginata J SO 40 Annelida Nereis sp. S S Amphitrite sp. 6 2 Enchytraeus abbidis 12 6 Heliodrilus caliginosus 6 6 Allobophora foetida 4 4 Lumbricus terrestris 3 3 Cerebratulus lacteus 4 o Coleoptera Carabidae ■ 2S 3 Galuita janus 30 o Helanotus fissilis 7 o Hydrophilus triangulis 3 o Pterostichus stygicus 10 4 Dytiscidae 25 o Gyrinidae iS o Dinetus assimilis 5 o Agabus semivittatus 4 o Tenebrionidae IS 7 14 ILLINOIS BIOLOGICAL MONOGRAPHS [224 Partial List of Animals Examined for Gregarines Number examined Number parasitized Passalus cornutus 24 Elateridae 7 4 Coccinellidae 30 3 Coccinella sp. 10 3 Coccineila novemnotata 5 3 Amara angustata 5 S Coptotomus interrogatus 7 S Ortlioptera Ceuthophilus stygius IS 8 Forficula auricularia IS Ichnoptera pennsylvanica 10 4 Gryllus abbreviatus 200 ISO Gryllus pennsylvanica 100 80 Melanoplus femur-rubrum 300 200 Melanoplus differentialis SO 10 Melanoplus acridior.um 5 S Melanoplus bivitattus ID 6 Schistocerca americana 2 I Dissosteira Carolina ID 5 Encoptolophus sordidis 2S IS Arphia sulphurea 5 S Hesperotettix pratensis ID 8 This list is incomplete for many animals were examined and not identified wlien parasites were not found. The numbers given above are approximate. LOCALITIES EEPEESENTED The hosts from which the parasites described in this paper were taken occurred chiefly in and around Urbana, Illinois. Some were taken in New Jersey, many on Long Island, and the marine material from Long Island Sound; material was received from Haverford, Pa., Colorado Springs, Colo., and Lincoln, Neb., which afforded new data on the distri- bution of several species. SEAT OP INFECTION The most frequently observed location for the sporonts is the mid in- testine of the host. The parasites are not found in the esophagus, crop, or rectum except when the infection is very heavy. The pyloric caeca are sometimes infected and parasites attached to the intestinal walls have been recovered in great numbers from the coelom of a very few insects. Cysts are often recovered from the mid intestine but usually from the rec- tum. They can be easily procured from the moistened feces of those spe- cies in "which they are large enough and opaque enough to be distin- 225] STUDIES ON GREGARINES— WATSON 15 guislied. with the eye. I have been able to procure them in this manner from the Aerididae. Cross-sections of the host intestine reveal the fact that the sporonts lie close to the epithelial walls and are not scattered through the food' masses. In the Myriapoda, they lie deeply seated between the lobes of" the intestine where they are not easily dislodgd. Thus the parasites are: in position to absorb the richly laden digestive juices just before the lat- ter reach the villi, and are not in danger of being swept along to the ex- terior by the peristaltic movements in the intestine. In the Aerididae sporonts and trophozoites are found in the pyloric caeca as well as in the intestine. In the Myriapoda the sporonts are able to bore through the walls of the intestine and have been found, though rarely, in the eoelom. One species of the genus Steinina was found in a beetle in masses on the outside of the intestinal walls, projecting into the eoelom. At least one family, the Stenophoridae, is intercellular in develop- ment and the trophozoites are embedded in the intestinal walls of the host; in the Gregarinidae, however, one end only of the trophozoite is projected into the epithelial cell of the host. SEASONAL VARIATION WITHIN THE HOST Investigation of the seasonal variation of gregarines was confined to the Aerididae and the Gryllidae, of the order Orthoptera. It extended over a period of two years. Locusts were collected around Urbana from early spring until about June 20, and were then very generally para- sitized but the number of parasites per host was small, averaging from one to ten. The nymphs of the Aerididae which hatch in the early spring were not infected in April but showed a slight infection when examined in June. In the fall, observations were again made at Urbana and disclosed a considerable increase in parasitism. Nearly every locust examined was heavily infected, fifty parasites being an approximate minimum. The same increase in the fall was found to be true of the gregarines in crickets. About fifty adults were examined at Urbana in June and it was found that only five or six were infected, and these with very few parasites. In the fall of the same year practically every cricket exam- ined revealed a heavy infection. Crickets were examined frequently throughout July and August of two successive summers at the Biological Laboratory, Cold Spring Har- bor, L. I. The parasitism here steadily increased from sparse to heavy inside of two months. Conditions there were particularly favorable to the rapid increase. The crickets were collected on the Sand Spit, a long narrow peninsula separating the inner and outer harbors, and were taken 16 ILLINOIS BIOLOGICAL MONOGRAPHS [226 from under the flotsam and jetsam which is brought to the inside of the spit by the incoming tide. There are no waves on this inner beach to change appreciably the upper limits of the tidal zone and the crickets were undisturbed. The cricket population is large and flourishing be- cause of the influx of organic debris. Thus the insects are confined to a restricted habitat and as cysts are produced and the spores scattered, the animals are reinfected over and over again. A number of crickets were taken in August from debris along the shores of Northport Harbor and Huntington Beach, Long Island, and all were uninfected. Both these localities are part of the exposed shore o£ Long Island Sound. A number were taken inland at Arlington, New Jer- sey, and were also uninfected. Practically every cricket examined in the late summer at Cold Spring Harbor and at Oyster Bay (four miles dis- tant) was infected. The only explanation which can be. offered by the writer for these phenomena is that the spores, having once become estab- lished in restricted area, have not yet found the means of becoming scat- tered broadcast but reproduce themselves in enormous numbers in re- stricted localities. RELATION OF PARASITE TO HOST TISSUE The effect of the parasite on the host is a subject still under discus- sion. Very little actual investigation has been carried on in this field but it is one which offers many interesting problems in biological chemistry. In the growing stages, the Eugregarine is either completely intercel- lular without an, epimerite, or possesses an epimerite by which it is at- tached to the epitelial cells of the host intestine, this factor depending on the family to which it belongs. All the Acephalinae (including Monocys- Us) and some of the Cephalinae (e. g. the Stenophoridae and the genus Frenzelina of the Gregarinidae) are intercellular; most of the cephaline Eugregarinae are not, however, intercellular but possess epimerites which alone penetrate the host cells. When the parasite is completely intercellular, the sporozoite pene- trates the free end of the cell, works its way inward by ameboid move- ment (Leger and Duboscq, 1909) and comes to rest in the vicinity of the nucleus. The parasite at once begins to affect the nucleus, causing the breaking up and rearrangement of the chromatin into small more or less spherical bodies which react differently to the stain than do the normal nuclei. The cytoplasm also is affected chemically for it stains less deeply than the normal cell cytoplasm. Siedlecki (1901) thinks these changes are due to a substance secreted by the parasite. Using Monocystis ascidiae for material, he found that the parasitized cell is at first greatly enlarged. The parasite within this enlarged cell then increases enormously in size so that the host cell and its 227] STUDIES ON GREGARINES— WATSON 17 contents may be ten or more times the size of the normal epithelial cell ; the parasite finally breaks out, for its rate of growth exceeds that of the epithelial cell, whereupon the latter shrinks and finally disappears, the adjoining cells gradually filling in the space left. The author says the chemical substance secreted by the parasite at first stimulates growth in the epithelial cell and later 'retards it, killing the cell, the parasite escap- ing after dissolution has set in. The normal excretion must be emptied into the cytoplasm of the epithelial cell of the host and may provoke changes therein but whether or not the cell is killed by the entrance of this foreign substance is a question. There is no other source of food for the parasite than by absorption from the cell which surrounds it, and it appears to the writer that the shrinking of the cell is due at least in part to the gradual withdrawal of its liquid content and the absorption of the latter by the contiguous parasite. How else the intercellular parasite grows is not easily explained. If the host cell is killed by toxins which are the excretory products of the parasite, the dead protoplasm is grad- ually used up as food for the growing organism. An animal is generally poisoned by its own excretory products ; the gregarine would seem to be an exception unless it is possible that the host cell remains alive and throws off the excretions of the parasite along with its own. Those parasites which are not intercellular possess epimerites by which they are attached to the free end of the epithelium of the host, the rest of the parasite lying in the lumen of the intestine. Five questions may be asked in this connection : (1) Does the epi- merite absorb food from the parasitized epithelial cell? (2) Does the epimerite absorb from the latter all the food that the gregarine receives ? (3) Does the epicyte of the gregarine body absorb all the food from the lumen of the intestine, and the epimerite act only as a holdfast organ? (4) Is a toxic substance given out through the wall of the parasite into the lumen of the intestine which is absorbed by the parts of the epithelial cells nearest the surface ? Laveran and Mesnil (1900) state that in Pyxvnia frenzeli the cell to which the parasite is attached at first greatly hypertrophies then atro- phies and finally disappears completely about the time the cephalont is ready to discard the epimerite and live free in the intestine. The hyper- trophy, they say, is due to an increase in the liquid content of the cell only, with a decrease in the density of its cytoplasm and nucleus. They do not attempt to give an explanation for the cause of the phenomenon. Leger and Duboscq (1902) think- this hypertrophy is only apparent and not real, for the penetration of the sporozoite into the cell irritates it so that the cell contracts in length at the same time increasing in width, the latter phenomenon giving rise to the idea that there is hyertrophy. They think the parasite absorbs the cell content through the epimerite 18 ILLINOIS BIOLOGICAL MONOGRAPHS [228 alone, and that constant and steady increase in the withdrawal of the cell sap accounts for the apparent atrophy. Pyxinia mohuzzi (Leger and Duboscq, 1902) possesses a long tongue- like epimerite (Fig. 98) which extends longitudinally through the pene- trated cell as far as the mesothelial layer of the intestine. The penetrated cell seems to be uninjured by this epimerite and the authors think the animal absorbs blood from the capillaries in the mesothelium by means of the epimerite. The Dactylophoridae, e. g., Nina gracilis Grebnecki (Fig. 30), have epimerites with many long radices, which Leger and Duboscq (1902: 458) state penetrate at many places several adjoining cells and probably function as an apparatus for nutrition. Many genera, Beloides, Pyxinia, etc., have a long central style in the epimerite which punctures the cyto- plasmic vacuoles and absorbs the cell sap directly. Siedlecki (1901:98) says the long jBlaments from the epimerite of Nina gracilis penetrate into the epithelial layers between the cells and do not puncture the cells themselves, as Leger and Duboscq think. Minchin (1912) says that the cytoplasm of the cell is absorbed by the parasite, which I infer to mean used as food, and that ' ' when the cy- tozoic phase is past and the host cell exhausted, the parasite drops off, shedding its epimerite." The present writer agrees with Leger and Duboscq and with Minchin that there is absorption through the epimerite. When a free cephalont is stained, its epimerite is seen to contain considerable endoplasm and not to be merely an ectoplasmic structure filled with sap. Moreover, stained sections of parasitized epithelium reveal the presence of attached eepha- lonts which are transparent or nearly so and which do not absorb the stain. Living material often contains large numbers of free cephalonts which contain but very little protoplasm or none whatever. These facts lead to the theory that the epicyte is not yet in physiological condition to absorb fluids from the intestine but that all such absorption takes place through the epimerite. "Whether or not the epimerite possesses an epicyte of different structural character from that of the rest of the body is not known. It does, however, possess a very delicate, fragile, highly per- meable layer susceptible to slight changes in osmotic pressure. The sug- gestion may be made that because the chemical constituency of the fluids in the lumen of the intestine and in the epithelial cells is obviously dis- similar, the parasite may or may not be able to absorb either of these fluids through the epicyte ; and if they are absorbed may not be nourished by one of these ingested fluids. The fact that the epimerite often con- tains protoplasm while the rest of the cephalont is still transparent or nearly so and that the cephalont remains nearly transparent as long as the epimerite persists, leads to the theory that whereas at first all the ab- 229] STUDIES ON GREGARINES— WATSON 19 sorption takes place through the epimerite, as the cephalont develops there occurs a gradual change in food from the predigested cell sap to the juices free in the intestinal tract as well as a transfer in its mode of ab- sorbing these substances from the epimerite to the general epicyte of the body. The general epicyte of the body may be physiologically different when the cephalont is very young from that when it is nearly ready to discard the epimerite. The third question : Does the epicyte of the gregarine body ahsorb all the food from the lumen of the intestine and the epimerite only act as a holdfast? has been answered above in the negative. There may come a time when maturity approaches and the epimerite is at the point of being discarded when the question may be answered in the affirmative ; during the greater part of the cephalont life, however, the epicyte is probably ineffective in absorbing nourishment. 7s a toxic substance given out into the parasitized cell through the epimerite of the parasite? Siedlecki (1901 :100) says the presence of the parasite within the cell (Monocystis ascidiae) incites hypertrophy, then atrophy, and that these phenomena are due to the chemical action of the parasite. In another species, however, Nina gracilis, which possesses nu- merous long protoplasmic filaments which penetrate deeply into the epi- thelium of the intestine, the author says of these threads "Tous ces changements provoques dans repithelium sont de nature pure- ment mechanique." He has observed changes in form and displacement of the cells but re- gards these as unallied to the hypertrophy and atrophy which is induced" by chemical excitation. Siedlecki finds in one instance a chemical effect excited by the pres- ence of the parasite in or attached to a cell ; in another species purely a mechanical affect ; while Leger and Duboscq, as mentioned, believe the ap- parent hypertrophy due to mechanical irritation of the parasite upon the cell rather than to any toxin secreted by the parasite. Yet illustrations given by Leger and Duboscq to prove a mechanical effect indicate a dif- ferent staining reaction in the case of many of the parasitized cells and a rearrangement of the chromatin in the nucleus unlike that in normal cells. The last question is stated as follows : Is a toxic substance given out through the epicyte of the parasite into the lumen which is absorbed by the parts of the epithelium nearest the surface ? It is often the case that the free end of the cell is shrivelled first. This end is nearest the hypo- thetical center of influence of the toxin which would be given out through the body of the parasite exposed in the lumen. It is also the end which is penetrated by the epimerite and the part naturally used as food first. The fact that the whole cell often reacts differently to the stain and not 20 ILLINOIS BIOLOGICAL MONOGRAPHS [230 the outer end only, and that the deep seated nucleus is affected by the very small parasite indicates the untenability of this theory as a cause of cellular reaction to the parasite. A theory for the shrivelling of the parasitized cell may be derived from the facts of liquid pressure. The cell wall is normally under some pressure from within, due to turgor. When the cell is punctured by the sporozoite, some of the cell sap might ooze out. Most of the liquid content of the cell is, however, contained in vacuoles and not liable to be affected by the puncture. The viscid cytoplasm of the cell would prob- ably be unable to find exit through the small opening. The puncture is as small as is the penetrating sporozoite and closed by the same. The parasite grows rapidly, enlarging the opening only as fast as the para- site grows. I have in no instance seen a section wherein the cell wall was torn by the growing animal, and in every instance the two fitted together tightly so as to form seemingly one layer at the neck of the epimerite. Thus the theory of loss of cell content by the oozing out through the punc- ture made is untenable. MOVEMENT IN GKEGAKINES Movement in Gregarines has probably been observed as long as the animals themselves. Dufour (1837 :11) said "Leurs movements sont fort obscur et leur locomobilite est d'une lenteur extreme; cependant je les ai constates." Siebold (1837:408) doubted that Gregarines were animals for he saw no movements. KoUiker (1848:32-3) described movement of the gliding type as "Eine langsam vorwartschreitende Bewegung ohne sichtbare Contractionen der Leibeshiille." He also noted the bending movement and describes it as follows : "Bewegung nach dieser oder j'ener Richtung durch mehr oder minder energische, auf verschiedene Weisen sich combinirende Zusammen- schniirungen der Leibeshiille." KoUiker did not attempt to explain the cause of these movements but he answered the question raised by Siebold "Are the Gregarines ani- mals?" by describing the violent contractions seen in many of his new species, movements which only animals possess. Leidy (1849:232) "detected movements of an animal character," and discovered the longitudinal striations of the epicyte which he thought were muscular in function. Van Beneden (1872) discovered the network of transverse fibrillae which Schneider (1875:505) called the myocyte. Contractility of the 231] STUDIES ON GREGARINES— WATSON 21 elements in this myocyte has since then been assigned as the basis for the bending movements of Gregarines. The first explanation for the gliding movement was oifered by Sche- wiakoff (1894) who supposed a gelatinous secretion from the posterior end of the body formed a stalk and that as the animal secreted new addi- tions to this stalk it pushed itself forward by the same amount. Porter (1897) probably without knowledge of Schewiakoff's theory proposed the following hypothesis : "It [locomotion] is a 'very slow movement of translation in a straight line' without any apparent contraction of the walls of the body. It is probably caused by a very slight undulatory motion of the under surface of the animal." Crawley (1902:420; 1903:57), unaware of Porter's hypothesis, came to the same conclusion that an undulatory movement on the under side of the body is the basis for locomotion ; and he disagreed with Sche- wiakoff's explanation. My observations on movement in Gregarines have been chiefly con- fined to the species Leidyana erratica of the family Gregarinidae because of its activity and the readiness with which material is obtained. In the normal intestinal juices of the host when the intestine is first opened, practically none of the animals are in motion ; they lie rather in inert masses from which the name Gregarine is derived. Since the juices rapidly evaporate and cannot be secured from other animals in sufficient abundance to observe normal movement over a considerable portion of time, artificial media must be used, the most common being distilled water. This causes the animals to disintegrate after periods varying from fifteen minutes to three or four hours, depending on the age of the parasites and their consequent ability to adapt themselves to a change in external pres- sure. The young, fragile animals disintegrate rapidly; the oJdest often resist the change in external pressure for several hours. When an epi- merite is present on a free individual, it is quickly ruptured in water. Egg albumen is not a satisfactory medium in which to observe mo- tion, for the parasite has great difficulty in ploughing its way through the thick substance. Eupture of the walls is prevented by its use because of a similarity in density between the animal protoplasm and this medium. Various acids in 0.5% solution were used and their effects on motion noted, among them being hydrochloric,nitric,acetic,sulphuric, and tannic. All of them killed the animals very quickly and caused the protoplasm to collect in masses ; the epicyte was also often ruptured. Chloroform and sulphuric ether in 0.5% solutions produced no apparent structural changes but the parasites were quickly anesthetized. 22 ILLINOIS BIOLOGICAL MONOGRAPHS [232 Normal salt solution acts as a stimulant to motion and in it the para- sites remain alive and active longer than in water. It is therefore the best medium in which to observe motion. Sea water has practically the same effect as normal saline. Movement of location consists of a uniform gliding progression with no apparent localized motion of the body. It is best seen in animals from a freshly opened host intestine mounted on a slide and supplied with an abundance of light. The parasites are negatively heliotropic and conse- quently attempt to avoid the Ught rays by moving rapidly from the tis- sues toward the periphery of the cover slip and down the sides until they encounter masses of debris under which they try to hide. The rate of progression has been measured in several instances. It averaged 0.8 micron per second in Leidyana erratica. The same individ- ual is able to increase or decrease its rate of motion through a consider- able range. A sample set of successive rates, measured at intervals of 15 seconds, reads as follows : 0.7, 1.8, 4, 5.6, 2.8, 1.5, 0.8, and 0.0 per second. An accompanying diagram (Fig. 233) illustrates progression combined with bending movement and the distances covered in successive time in- tervals. In the Stenophoridae motion of progression is slower, an aver- age being .007 per second for two species, one of which was five times the length of the other and of correspondingly greater volume. Just how the progressive movement is effected is a matter much dis- cussed. Schewiakoff (1894) makes the statement that it is caused by the secretion of a hollow gelatinous "stalk" formed of contiguous threads at the posterior end of the body which pushes the animal forward. He says that the gregarine is able to move only until its store of secretion is ex- hausted and cannot go on until it has accumulated the materials from which to secrete a new addition to the "stalk". Upon cutting off most of the light from the field, there can be seen many fine threads leading from the posterior end of the gregarine back to a mass of debris from which it is apparently trying to extricate itself. A slight motion of the microscope or of the table beneath will cause the threads to tremble ; but even a slight movement of the cover slip does not rupture them. I have often observed the animal swinging about in an are at the end of this fastened thread or strand of threads without break- ing it. This was noted in twenty-five instances in a single field and was repeated by the parasites until their walls were ruptured and the proto- plasm oozed out. After a mount has been made for some time and the gregarines have become scattered about in the debris, many animals can often be seen headed away from inert masses, moving a short distance forward and then being jerked quickly back as if by some invisible spring. When an animal is able to free itself, the relase is sudden and the distance trav- 233] STUDIES ON GREG ARINES— WATSON 23 ersed often as great as the time it takes is short. The release may be com- pared to the cutting of a tense cord. Generally, however, the parasite is not able to effect its release and keeps on trying until the walls are rup- tured or death ensues from some other cause. I have never observed backward gliding movement. The only back- ward motion seen was the sudden jerking mentioned above. This phe- nomenon may possibly be accounted for in the following manner : The animal exerts considerable effort to move forward against the backward pull of the threads and debris behind it. Its body becomes stretched out long and narrow by the contraction of the myonemes. These myoneme fibrillae suddenly relax and the body becomes shorter and normal in shape. As the tension on the caudal threads is thus released, the body is drawn backward with a sudden jerk. The motion is thus passive, a sim- ple reaction and not actively incited motion in a backward direction. It is not to be denied, then, that there are formed gelatinous threads which seem to fuse and form a thick thread or strand from the poste- rior end of the body, but these threads are obviously an hindrance rather than an incentive to progression. My theory concerning the rea- son for the presence of such a group of threads will be discussed later. Granted here that such a group is present, it obviously comes from the animal itself and is carried to the posterior end of the body by the longitudinal ridges which gregarines possess (see Fig. 243 for illus- tration of these longitudinal ridges). The animal in a mass of debris tries to liberate itself. In this motion there is secreted a lubricating substance which in a medium other than the normal digestive juices ad- heres to the debris. In endeavoring to get free, a great deal of energy is expended and considerable lubrication secreted; and thus the thread is formed from which the animal is unable to extricate itself. Each added trial only causes more secretion to be poured out and makes the snare the more secure. The body becomes drawn out long and slender indicating the strain which the animal undergoes (Fig. 236). I suggest the hypothesis that normally there is a secretion which reaches the posterior end. When a parasite is moving through a me- dium in which there is fine scattered debris, it picks up much of it. After a considerable accumulation has taken place, one of two things may happen: The end masses may drop off by their own weight, the force exerted by the strand of threads being less than that exerted either by the progressing animal or by the dead weight behind. If the strand withstands the stress exerted by the moving animal but the dead weight exerts greater force than the combination of the other two, the strand and the animal, the parasite is caught and eventually dies. The presence of the caudal threads can often be demonstrated with carmine. In a freshly made mount the carmine does not seem to adhere 24 ILLINOIS BIOLOGICAL MONOGRAPHS [234 and I have never been able to demonstrate the presence of threads in a freshly opened intestine. The medium must then be other than the nor- mal digestive juices. It thus seems possible that no strands are present in the normal condition but that they harden only after being for some time in an unnatural medium. Instead of hardening and condensing in the host, the constituents of the secretion are probably dissolved in the digestive juices as fast as formed. As the reason for the presence of the semi-gelatinous secretion from the body, I accept the view of Porter which states that movement is probably caused by a very slight undulatory motion of the under sur- face of the animal. Just as Limax moves forward by a slight ventral, and dorsally imperceptible, muscular movement in a vertical direction on an underlying surface the friction of which is caused by the secretion of a sticky mucus, the gregarine moves forward by imperceptible ver- tical movements in the myonemes on that side of the body which hap- pens to be ventral at the time, friction being produced with the under surface by the exudation of mucus from the body. That there is a se- cretion from the whole body and not only from the posterior region is demonstrated by carmine which adheres in fine particles to all parts of the animal. It was shown by Schewiakoff that there are tiny pores between the longitudinal ridges. These probably serve as exits for the secretion. The longitudinal ridges carry it backward and away after it has served its usefulness in effecting motion. The secretion is in the form of threads simply because it is constricted into narrow lines by passing backward between the tiny ridges. The threads are not necessarily con- tinuous but may be often broken. Thus I am of the opinion that the secretion at the posterior end of the body does not produce motion, but that it is a waste product by the time it has reached this end ; it is likewise effective as shown above in in- hibiting motion in an unnatural medium, as well as in producing it. Besides the simple progressive movement, a twisting or bending movement is commonly observed. The body bends often with little or no change of position. This bending involves chiefly the anterior half of the deutomerite. The protomerite is turned from side to side like the head of a higher animal while the parasite is progressing from place to place. The protomerite, of itself, apears however to be incapable of movement and not the slightest change in form has been noticed. The region of greatest capacity for motion is the anterior end of the deuto- merite. The endocyte of this region flows out into small pockets made in the elastic epicyte and as a group of two or three small outpushings is made on one side, close together, the protomerite falls to the opposite side. An outpushing of several small pockets just below the bent over 235] STUDIES ON GREGARINES— WATSON 25 protomerite tends to straighten it; if half a dozen or more are formed in a circle around the anterior end of the deutomerite, the protomerite win sink into the central depression and often be obscured from sight. The parasite is able to move through a place much narrower than the width of the body by the contraction and expansion of the epicyte, as in the instance of an amoeba. Bending movement when the animal is out of its normal habitat may be due to external stimuli such as the endeavor to avoid light and the water medium. "When in the normal habitat, the animal does not need to move about in search of food, there is no light to avoid, and the chief function of the bending movement when the parasite is in the in- testine is probably the formation of a cyst. Two animals rotate about an imaginary axis coming closer and closer together by bending more and more, and finally form a perfect sphere (see Figures 234, 235 and 238 J. The formation of cysts by the use of normal saline occurred in twenty-five minutes. The salt solution was removed as soon as the cyst was completely formed and' the cyst washed with distilled water. It de- veloped to completion with the exudation of ripe spores. Cysts have, however, developed in but little longer time in distilled water. SUMMARY 1. Normal salt solution is the best artificial medium in which to study motion. 2. Locomotion is effected by means of a progressive, gliding movement with no apparent localized motion of the body. 3. Progression takes place at the average rate of 0.8 per second in Leidyana erratica. 4. In artificial media there are formed gelatinous threads at the pos- terior end of the deutomerite. 5. These threads may be seen with a high power and a minimum amount of light in a mount which has been made for some time. 6. They do not occur in a freshly made mount. 7. The threads may be demonstrated with carmine granules in sus- pension. 8. The animal probably moves by imperceptible vertical movements of the myonemes of the side which is ventral at the time, and upon a surface whose friction is caused by an exudation of slime from the body of the parasite. 9. This mucus is secreted by the body and runs out through pores be- tween the longitudinal ridges in the epicyte. 26 ILLINOIS BIOLOGICAL MONOGRAPHS [236 10. The mucus runs backward along the longitudinal ridges to the pos- terior end and is discharged as a waste product in the form of broEen threads or strands. 11. The anterior half of the deutomerite is the region chiefly involved in bending movement. 12. The protomerite is incapable of independent bending movement. 13. The normal object of contortion is the formation of cysts. 237] STUDIES ON GREGARINES— WATSON 27 PAET II MOEPHOLOGY OF GEEGAEINES MOEPHOLOGY OF THE SPORONTS The structural characteristics of the Gregarines have been de- scribed by many writers, including Delage and Herouard (1896), Biitschli (1882), Minchin (1903, 1912), Doflein (1911), and others. For this reason I have not attempted to describe the general morphology of the group but rather to state facts of form and structure which I have observed in the two families under observation, viz., the Stenophoridae and the Gregarinidae. The Stenophoridae All of the species of this family are solitary. In all gregarines which reproduce sexually, the union of two sporonts is necessary but in the Stenophoridae this intimate association lasts only while the cyst is being made and not, as in some families, during the greater part of the sporont life. The cyst is probably formed quickly and this union very brief; no sporonts were seen in the process of cyst formation. One characteristic of almost all the described Stenophoridae is the great length of the deutomerite as compared with the protomerite. The ratio is seldom less than 10 :1 and is often as high as 30 :1. The protomerite is not constant in shape; it is, however, generally more or less conical, rounded at the apex, either as a simple cone (Fig. 7) or constricted or dilated slightly halfway from apex to base (Figs. 14, 16, etc.) ; there is generally, but not always, a small papilla at the ante- rior end (Fig. 24). The epimerite, which is superimposed upon the pro- tomerite of the cephalont, contains some endoplasm which is continuous with that of the protomerite through the narrow neck connecting epi- merite and protomerite. At the apex of the protomerite of the sporont, i. e., an individual which has lost its epimerite, the epicyte is very thin and the endocyte reaches nearly to the top. When the epicyte of the sporont upon the slide is ruptured, this rupture takes place at the apex and is accompanied by an extrusion of protoplasm at this point ; the en- docyte breaks first at its weakest place and in this family the apex of the protomerite is the weakest point. The thinness of the ectoplasm at 28 ILLINOIS BIOLOGICAL MONOGRAPHS [238 the apex gives rise to the idea that there is a pore here.* I am of the opinion that there is no pore but that the epimerite severs its connection with the trophozoite by gradual constriction at its short neck and drops off as a ball. The apex of the protomerite closes over completely, leav- ing a trace of the narrow channel in the epieyte by which the endoplasm of the two parts was in connection. That there is an opening to the ex- terior at this point in the sporont seems doubtful for I have never seen the extrusion of endoplasm in a freshly taken sporont to which slight pressure was applied; it occurred only when the animal had been kept on a slide in a normal saline or water medium, and then only after from fifteen minutes to an hour, or until the decrease in the density of the outside medium had had time to affect the parasite. Not all protomerites of the Stenophoridae are conical in shape. In Stenophora irolemanniheger and Duboscq (Fig. 13) the protomerite is shaped like a flattened cork fitting into the neck of a bottle, the deuto- merite surrounding it in a thin layer nearly to the apex ; in Stenophora spiroboli Crawley it is almost hemispherical in shape (Fig. 70). In sporonts of the Stenophoridae I have seen, the deutomerite is long and slender. Leger and Duboscq record dimorphism in several species, Stenophora silene (Figs. 22, 23), S. chordeume (Figs. 24, 25), S. varians (Figs. 16, 17), etc., wherein the sporonts are both elongate and subglobular in shape. However, I have not observed an authentic and unquestionable case of dimorphism. The long, slender sporonts are, nevertheless, able to contract so as to be of quite a different shape from the normal. Immature specimens of several species are subglobular and stain more deeply than the sporonts but no mature subglobular speci- mens have been seen. There is generally a constriction at the septum which distinctly dif- ferentiates protomerite and deutomerite; this is lacking in Stenophora spiroholi Crawley (Fig. 70) and in S. robusta Ellis (Fig. 26), and is only slightly developed in S. polydesmi (Lankester). The widest part of the deutomerite is generally the anterior third; sometimes the deutomerite is a cylinder more or less equal in width throughout. A combination of the two shapes is seen in Stenophora diplocorpa (Fig. 21), in which the deutomerite gradually broadens and then contracts in the anterior half, being conspicuously constricted at the middle and cylindrical posterior to the constriction. The deutomerite terminates in a broadly rounded, truncated, or conical extremity. The protomerite and deutomerite differ greatly in endoplasmic content, and therefore in color and consistency. The protomerite is *As stated by Ellis (1912b) in the Diplopoda. 239] STUDIES ON GREGARINES— WATSON 29 always the less dense, being often nearly or quite transparent; the granular content is sparse and the large irregular granules are often clustered near the septum, the rest of the space being filled with a color- less fluid. The two parts differ in staining reactions also. The deuto- merite contains fairly homogeneous endoplasm always densest at the center of the mass, which is generally in the anterior third of the body. In the posterior part of the attenuated forms, there is often so little en- doplasm that the animal is transparent in the last fifth to third of its body. The deutomerite is generally gray or black in its densest regions and a lighter gray in regions of less density. The nucleus may be either spherical or ellipsoidal in the sporonts, and varies considerably in relative size in different species. It generally contains one karyosome in mature sporonts of this family, sometimes more than one, but never many, and the karyosomes stain deeply, often revealing the presence of one or two very small centrioles within. Longitudinal striations in the epicyte seem to be characteristic of the family, and myonemes have been observed in a great many instances. See figure 243 for these structures in Leidyana erratica, one of the Gregarinidae. It is probable that both types of structures are invariably present in motile gregarines and form the material foundation for pre- vailing ideas as to the cause of motion. The epimerite seems to be an inconstant factor. Sometimes it is well developed and even retained in specimens free in the lumen of the intestine (Stenaphora nematoides, Fig. 15; 8. diplocorpa, and 8. lacta- ria). Generally, however, workers who have not sectioned the intestines of hosts have failed to find any trace of an epimerite. This is possible from the fact that development is intercellular and not extracellular as in the Gregarinidae, in which family the epimerite alone penetrates the eeU. The whole trophozoite lies embedded and is able to obtain nourish- ment by osmosis, just as it does when it becomes a sporont, taking food in the former instance from the cell originally penetrated and those sur- rounding rather than from the lumen. Often intercellular parasites are found without epimerites (Leger and Duboscq, 1904, PI. XIV, Figs. 1, 3, 4) and yet in the same section there may be smaller specimens which show the epimerite. The reason for the presence of an epimerite at all is not evident unless it is an ancestral vestige, for it disappears while the animal is still living an intercellular existence. The larger embedded trophozoites are found in various positions in the host cells, generally, however, headed away from the lumen, i. e. with their protomerites contiguous with the mesothelial lining of the in- testine. Infrequently one is met which has the protomerite turned toward the lumen (Leger and Duboscq, 1904, Fig. 6). Individuals of 8tenophora lactaria have frequently been found boring their way, pro- 30 ILLINOIS BIOLOGICAL MONOGRAPHS [240 tomerite first, througli the mesotlielial walls of the intestine into the coe- lom, and in sections of the host some specimens have actually been found in the coelom lying close to the coelomic epithelium of the intestine. Dur- ing the boring process the muscular tissue in the wake of the parasite is destroyed, leaving the surrounding tissue shredded and contorted. The adult parasites seem to prefer lying loose between lobes or clus- ters of intestinal cells rather than living in the open lumen. The inter- stices of the lobes are very frequently occupied by large adult gregarines. The sporozoite is spindle shaped and swells in the lumen. It pene- trates the free end of a cell between the cilia and undergoes develop- ment within the cell. The first trophozoic stage I have seen is the small, completely formed body without a protomerite, lying embedded with its epimerite at the distal end of the cell next to the mesothelial layer. It undergoes considerable growth here with the consequence that the cell is destroyed and the parasite comes to lie in a self -formed cyst between two cells, often affecting parts of these cells and causing the cells for some distance around to be greatly compressed. Then the epimerite dis- appears and the protomerite develops and becomes more or less flattened against the basement layer of the cell. The trophozoites emerge into the lumen through the space left by the originally destroyed cell. The nu- cleus of the trophozoite of Stenophora lactaria is spherical; it begins however to acquire its ellipsoidal form while still in the intercellular stage. The Gregarinidae The parasites of this family become associative while they are quite immature and long before they are ready to form cysts. The shape of the sporonts remains fairly constant whether they are young or fully ma- ture. The sporonts of the genus Oregarina are always more or less obese, and very frequently dolioform. The protomerite is much larger than in the Stenophoridae in comparison to the size of the body. In length, it varies from one-half to one-eighth the total length of the body. It is fre- quently hemispherical and as often cylindrical, rounded in front, but it is more than twice as high as wide ; it is rarely conoidal. There is some- times a slight indentation at the apex. The epicyte is fairly thick throughout but is thicker at the anterior end of the body aiid at the septum than elsewhere. The deutomerite is nearly always wider than the protomerite. It is fairly regular in shape throughout the family, being generally widest at the middle or slightly anterior thereto and gradually tapering both an- teriorly and posteriorly. The posterior end is always rounded; it is never sharply acute. 241] STUDIES ON GREGARINES— WATSON 31 The endoplasmic content of the prgtomerite and deutomerite differ more in density than in character of the granules. The protomerite con- tains homogeneous granules about the same size and consistency as those of the deutomerite but fewer in number, rendering this portion always. ■ less dense. Myonemes are difficult to detect in the Gregarinidae, even with am oil immersion objective, when the animals are alive. They can be seem in longitudinal sections of adults as large deeply stained dots seemingly- larger protoplasmic granules, situated at the edge of the endoplasm (Fig.. 232). Cross sections naturally do not reveal their presence. In total mounts and with an intravitam stain they can be seen as a delicate net- work of fibrillae extending around the animal (Fig. 243). Longitudinal striations in the epicyte^are rendered visible by sim- ply crushing the animal on- the slide and liberating the dense endocyte. They are very delicate parallel striations visible with the oil immersion lens and situated on the outside of the epicyte. They may be seen in both protomerite and deutomerite and traced continuously fron^ one end of the animal to the other (Fig. 243). They do not converge at the ante- rior and posterior ends, being continuous over the ends as at other parts of the body. The writer has never Seen between the striations the pores which Schewiakoff says serve for the extrusion of the mucus. The nucleus in the genus Gfegarina is always spherical. In the tro- phozoites and in immature sporonts there is often but one large karyo- some and never more than five or six. As the size of the animal increases, the karyosomes increase in number and decrease in size and are scattered irregularly throughout the nucleus. In mature sporonts they are often arranged in a twisted chaplet.and are then too numerous to count. One of the reasons why maturity of the cyst and its dehiscence in the Grega- rinidae occupies so short a time (two days) may be that the nucleus of the mature sporonts has already broken up into numerous small ele- ments before cyst fornlation has taken place and only needs to lose its wall while in the cyst for these particles to surround themselves with a. portion of the sporont endoplasm and becomes gametes. In the Steno- phoridae, the nucleus of a mature sporont contains but one large karyo~ some which after cyst formation has taken place must break up into con- stituent elements. The epimerite of all the Gregarinidae in which it has been observed is a large globular slightly stalked or sessile structure which is often re- tained after its usefulness is gone and the trophozoite is liberated in the lumen (Figs. 224 to 227). There is little endoplasm present in the nearly transparent epimerite which can be demonstrated with an intravitam, stain. 32 ILLINOIS BIOLOGICAL MONOGRAPHS [242 LIFE HISTORY OP A TYPICAL CEPHALINE GREGAEINE The life history may be outlined briefly as follows : Sporozoite — tro- phozoite — sporont— gamete — zygote — spore — sporozoite. The sporozoite is a very minute falciform body liberated from the spore by the action of the digestive juices of the host which has swallowed it.* This small body apparently possesses no means of locomotion other than the extrusion of protoplasm. It lodges among the cilia of the intestinal epithelium and bores its way into the cell by ameboid movement. (Leger and Duboscq, 1909). Penetration is probably effected by the excretion of a toxin which lowers the resistance of the cell wall. It either merely punctures the wall and projects a small portion of its body into the cell, as in most Gregarinidae, or completely embeds itself in the cell mass, deriving its nourishment from the cell sap, as in the Stenophoridae. As soon as the sporozoite begins to absorb nourishment and to grow, it becomes a tro- phozoite. A combination of factors determines when the trophozoite shall be liberated into the lumen of the cell. The destruction of epithe- lial cells and the growth of the parasite go hand in hand and when the cells no longer supply sufficient nourishment or when the activity of the parasite causes it to release its hold, the trophozoite is liberated into the intestine and thenceforth absorbs nourishment from the fluids of that cavity. After the cell has been destroyed and the parasite liberated, the epi- merite is no longer useful and drops off. With the loss of the epimerite and change in habitat, the animal becomes a sporont. At some stage in sporont life, generally an early one, a member of the genus Gregarina attaches to one end of the body another sporont, the two forming an as- sociation. In genera in which the sporonts are solitary, attachment of two sporonts takes place just previous to cyst formation. Upon reach- ing a certain size or density or because of some unknown internal factor, the two sporonts rotate about a common axis and form a sphere. This spherical mass acquires a relatively thick gelatinous covering, the cyst, and leaves the body of the host with the feces. If it remains in a moist place for 48 hours, development proceeds as follows: The sporont nu- cleus breaks up into a myriad of small chromidial bodies, each small body acquiring a small amount of the residual protoplasm of the sporont. These nucleated particles are gametes. The gametes of the two sporonts are allowed to mingle by the beaking down of the separtion walls, when they fuse two by two and form zygotes. The zygote acquires a tough, resistant transparent covering and the content breaks up into eight parts, ♦There is some evidence to substantiate the theory that autoinfection occurs and accounts for the enormous number of parasites which is often present in a host. See last page of section on cysts. 243] STUDIES ON GREGARINES —WATSON 33 each with a portion of the zygote nucleus. The resulting body is an oc- tozoie spore. The spores are liberated from the cyst through spore ducts which are formed from the residual protoplasm of the cyst. They are scattered over the grass and ground by the wind and rain and are eaten by some host along with its food. Parasitism is thus accidental. The spores upon reaching the alimentary canal of the host are acted upon by the digestive juices and the spore wall absorbed. Upon the disappear- ance of the wall, the eight sporozoites are set free and the life history starts on the same cycle again. THE QUESTION OF SPORONT MATURITY The question may be raised in connection with the development of the sporonts and cysts : Can one detect a sporont which is fully mature and ready for cyst formation ? After many months of observation upon a number of species of several genera, I have come to the conclusion that full maturity can be detected and the imminent cyst formation pre- dicted. In a genus like Gregarina, in which the association of sporonts is a characteristic feature, the fact that specimens are in associations of two does not indicate that the sporonts are mature, for associations are often formed early in sporont life while the animals are very small and obviously immature. In fact many sporonts are seen in association which are much smaller than some cephalonts of the same species free in the intestine. The fact that sporonts are linked together in twos is not an indication of maturity. Density of the animals is often a criterion of maturity but not one upon which to depend. Cephalonts are transparent or nearly so; the small sporonts are but slightly opaque and opacity increases steadily with age, the oldest in many species being very dense and practically black in transmitted light. If, however, a host is starved a few days be- fore being opened, the parasites are likewise starved and become more or less transparent. Size increases with age and only the large individuals in any case may be expected soon to form cysts. While no one of these three characteristics can be used as a test of maturity of the sporonts, an association of large sporonts in which the individuals are well filled with protoplasmic granules and hence opaque, indicates without doubt that the sporont is mature. Movement of such an association is no longer the active motion of translation; the sporonts have become sluggish and tend to revolve.. When the revolution becomes fairly well established, it takes a spiral form and gives place to rotation. The animals finally become a compact spherical mass with a cyst wall which has been secreted during rotation. The sporonts are now in position to reproduce themselves. 34 ILLINOIS BIOLOGICAL MONOGRAPHS [244 THE CYSTS Observations on cyst formation and development, like those on movement have been confined chiefly to one species. In the Stenophori- dae I have not been able to procure the dehiscence of any cysts ; in the Gregarinidae observed, however, it was an easy matter to procure cysts and watch their development. Cysts were taken from moistened fecal masses or from the intestine by means of a needle and placed on slides. Bits of broken glass were used to raise the cover slip, and distilled water added. The cell was sealed with vaseline and placed in a petri dish well vaselined along the edges. Cysts of the Stenophoridae observed were spherical or slightly ellip- soidal. They are generally found in the posterior part of the intestine and were not seen until fairly developed and rotation had ceased. It is not difficult to determine in most cases that two individuals were in- volved in making the cyst. The line of separation is often indicated in the cyst and there is often a slight difference in density of the two conjugants. In one instance one sporont was nearly black and the other pale tan. This fact was not noted until after the cyst had been in the damp chamber half an hour. In all eases observed the cysts became lighter in color after being in the damp chamber a few hours. In freshly opened intestines, cysts do not show a clear hyaline layer but after expo- sure the extrusion of water causes the inner mass to shrivel and the epi- cyst to swell so that the whole diameter is greater than at first. Al- though cysts were kept in the damp chamber nine days no spores de- veloped. Whenever still intact, the cysts were crushed at the end of that time but there was no apparent differentiation of the protoplasm and none was revealed by staining. Most of the cysts were, however, shriv- eled and disintegrated. Cyst Formation in the Gregarinidae — Leidyana erratica This species is in its normal sporont stage non-associative. The young sporonts which have but recently lost their epimerites are nearly transparent but as age advances density increases, due to the absorption of food. The oldest sporonts are very dense and practically black in the deutomerite so that the nucleus is not visible when they are alive. The body in the young sporonts is long and rather slender, but it widens appreciably in the older ones. Middle-aged animals are very active in their movements but older ones are sluggish and tend to lie motionless in masses (Fig. 230). In dense, sluggish individuals, one may expect cyst formation to take place. The sporont retains its power to bend and twist after it has apparently ceased to use its progressive powers. Sluggish individuals 245] STUDIES ON GREG ARINES— WATSON 35 in rotation set in motion currents in the surrounding medium and slowly attract into this ever-widening circle of influence particles of debris or nearby gregarines. If debris is drawn into the whirlpool, it is not re- tained, but slips to the outside again. Another gregarine is, however, attracted and held probably because of the mucus on its exterior, and caused to rotate with the first one. If two gregarines are attracted, the force exerted by the first is too weak to hold both and one is invariably liberated. A sporont is apparently unable to make a cyst alone. A sin- gle sporont has been seen to rotate for three hours without succeeding in attracting another and then to straighten out suddenly and move to another part of the field. "When such an association is formed, the sporonts are not attached by particular parts of the body, as are associations of the genus Orega- rina, but are held together in a haphazard fashion by secretions only. In rotation the sporonts come closer and closer together laterally, slipping by a few sudden jerks until one does not project beyond the other, the protomerites bend around so as to meet the posterior ends of the deuto- merites (Figs. 234 to 236), the deutomerites projecting and contracting so as to leave no unfilled interstices until the result is a compact sphere. In one such process, there was formed in the middle of one side of each deutomerite a tiny cupped indentation and the two cups fitted together to form a perfect sphere. This sphere became smaller and smaller as the cyst developed and finally disappeared in the general breaking down of the inclosed sporont walls (Figs. 235, 238). The mass continues its slow rotation for hours. After a compact mass has been formed one can still distinguish the nuclei and the proto- merite and deutomerite of each sporont, the former by the pale tan color (Figs. 239, 240). This demarcation is lost and soon after the faintly vis- ible lighter nuclear areas disappear. The straight line which separates the two sporonts (their lateral walls) remains visible for twenty-four hours after the cyst has begun to form. It disappears finally and the cyst-ma*!? becomes perfectly homogeneous throughout (Fig. 241). All the time the mass is revolving there is being exuded from the two bodies the sticky, gelatinous, transparent secretion. This exudation follows the animals as very slender spiral threads and forms a spirally arranged layer constantly increasing in width as rotation continues. When rotation ceases there is formed around the cyst-mass an apprecia- ble layer of this gelatinous matter arranged as very fine concentric threads. Motion of the mass was watched in one instance to completion. My notes opposite the time of each successive complete rotation read as fol- lows: "Brings another gregarine into the vortex; the two rotate to- gether ; shoves a third gregarine out of the way ; retracts same ; the two 36 ILLINOIS BIOLOGICAL MONOGRAPHS [246 slip and slide until they form a perfect sphere ; central spherical area left between the two sporonts ; gelatinous layer forming around the rotating sphere ;the outer layer wider and distinct." The time for the first com- plete rotation of the solitary individual was one and one-eighth minutes. Approximately this rate is retained during sixteen rotations. The rota- tions then becomes slower as the mass more and more nearly approxi- mates a sphere. Two and one-half minutes, four minutes, and five min- utes are recorded for successive rotations. At the end of forty-five min- utes the cyst was complete but still slowly rotated at the rate of one ro- tation in from four to five minutes. When next observed, two hours la- ter, motion had ceased and there was present a gelatinous layer in thick- ness one-third the radius of the cyst. FuUy formed cysts which are still in the process of rotation were frequently taken from the host and they continue to rotate a half hour or more after removal. Cyst Development and Dehiscence When the mass has finished rotating, it is a beautifully homogen- eous, opaque, gray spherule surrounded by a thick, transparent, cyst wall fifty micra in thickness or half the radius of the inner mass. The mass begins to disintegrate in twelve to fifteen hours, the protoplasm becoming arranged in many dense areas (Fig. 242). The diameter of the inner mass decreases and that of the transparent cyst wall increases by the exudation of water from the inner regions. In twenty-four hours the protoplasm within the cyst wall has begun to shrink from the peri- phery. Five hours later (29 hrs.) the spore ducts are clearly indicated (Fig. 245) by dense accumulations of protoplasm on the periphery or orange colored discs on the cyst surface. From three or four to a dozen of these discs are delineated. The orange color is due to an accumulation of orange colored oil which dissolves and loses its color in ether. Soudan III stains it red. The oil can be pressed out from the cyst in large globules. The origin of this oil in the cyst is, of course, the endoplasm of the sporonts. The protomerite is tan in color and probably contains con- siderable oil ; the deutomerite may contain as much or more but the color is obscured by the great number of protoplasmic granules which render the whole very opaque. After thirty-five hours, the ducts leading from the periphery to the center of the cyst mass appear ; they resemble the spokes of a wheel. In a few more hours the spore ducts begin to project from the surface of the sphere; the center is depressed (Figs. 247, 248). By this time the indi- vidual spores are visible within the mass (Fig. 246). At the end of from forty-two to sixty hours, the spores are liberated (Fig. 249). Although from one to a dozen spore ducts begin to grow outward, not more than 247] STUDIES ON GREGARINES— WATSON 37 one has been seen to complete itself. This is accounted for prohahly by the fact that pressure is exerted on most of the incipient ducts by the slide and cover slip, and growth to completion thus inhibited. One duct is often directed horizontally between the two surfaces and it always is this lateral duct which develops and through which spores are extruded. When there is considerable debris in the vicinity of the developing cysts, the ducts are often coiled and twisted about the cyst itself. I have never been able to incite spore exudation without the use of a cover slip for even in a carefully sealed damp chamber there is enough volume within the chamber to cause sufficient evaporation to dry up the unprotected cyst. The duct which is formed is very long, 25 tnm. or eight times the ra- dius of the cyst (Fig. 249). The ducts grow inward from the periphery where they first appear to the region of the residual mass of protoplasm. Then they grow outward from the periphery until they acquire the enor- mous length attained in a few species. The growth outward is from the region of the periphery, the older portion being pushed ahead. The tip of the long duct is orange colored as is the disc from which growth be- gan, showing that the oil globules are pushed along with the first out- pushing of the tube. There does not seem to be an eversion of the duct here, as in Gregarina rigida and other species (Lankester, 1903:183). The spores emerge in chains which soon break up into small seg- ments. These spores (Fig. 255) are barrel-shaped and truncate at the ends. They possess an epispore and endospore easily discernible when a stain is used on the slide. They are slightly cupped at the ends. I think there is a corona of very delicate spines or cilia at each end which serves to hold the spores together in chains and to furnish a means of locomo- tion for the isolated spores. That spores do move from place to place is easily determined by watching a few chains of freshly liberated spores on a slide. (Care should be taken that the slide is undisturbed and not allowed to evaporate) . In a few hours no two spores will be left attached but they will lie in small clusters or scattered over a whole field. Sometimes spore ducts do not develop and the cyst has superficially undergone but little differentiation, yet upon crushing the walls after a day or so when the spore ducts should have been formed, perfectly formed spores emerge, to all appearances and staining reactions identi- cal with those liberated in the usual way. Nothing could be said of their potency as compared with those extruded normally. The content of the spores varies greatly. If the cyst is broken be- fore the spore ducts have had a chance to form, and apparently before the spores are ripe, they will be found to contain many small clustered or isolated chromosomes which stain deeply. All the spores from a given cyst are in approximately the same stage of development. Another broken cyst will yield spores with fewer chromosomes, from ten to fif- 38 ILLINOIS BIOLOGICAL MONOGRAPHS [248 teen, for instance. A cyst brought to completion yielded spores in which each of the many examined contained eight large chromosomes. These spores were watched for a day and at the end of the twenty-four hours delicate partitions were seen, between each two of which was contained one large chromidial body. These partitions represented lines of separa- tion between the eight sporozoites which were being developed (Fig. 255). I was unable to procure or find any liberated sporozoites by any of the following methods: 1) Some spores were left on the slide in a water medium; 2) others were placed in normal sodium chloride solu- tion; 3) the intestinal juice of a freshly killed cricket was run under a third cover slip on which were a few spores; and 4) spores were placed on a small mass of fresh intestinal epithelium. In the last two instances putrefaction was soon set up in the non-sterile tissues. Using spores of another gregarine (Frenzelina delphmia) from a crab, I ster- ilized some of the colorless blood from the heart of the crab by boiling it in a test tube and used the liquid as a medium but without inciting spore development. Cysts were crushed at various developmental stages and stained. The spores were found to be well developed before the spore ducts were formed, so the early stages of development are the sources of greatest changes. Immediately after the protoplasm of the cyst becomes collected in masses, small clear papillae begin to appear on the periphery of each mottled mass (Fig. 244). The layer of papUlae being formed, another develops beneath, until the three or four outer layers of the cyst show these papillae, the inner mass being residual non-metamorphosed pro- toplasm. The papillae soon become pinched off to form tiny globular bodies, «ach of which contains a deeply staining particle inside. These globular bodies are the gametes (Fig. 251). Upon crushing and staining a cyst in the gamete stage, I have repeatedly been unable to find the least evi- dence of a difference in shape or size or in staining reaction between the gametes from opposite poles of the cyst ; i. e., from each of the two con- stituent sporonts. The gametes are isogametes. That there is, however, a, difference between them is shown by the attraction of certain gametes for others. Before the partition wall between the two sporonts is ab- sorbed, the gametes of each side do not attract others from the same side of the partition. But when the partition wall has dissolved and the cyst is examined, it is seen to contain many 'double' gametes; i. e., gametes united in pairs (Fig. 252). If taken early enough, the gametes are seen to be barely contiguous at one point. The next stage observed is that in which each retains its identity but is fiattened on the side of attachment to the other (Fig. 253). Then the identity of each becomes 249] STUDIES ON GREGARINES— WATSON 39 lost and the result is a body twice the size of the original gamete, with a nuclear content made up of the fusion of that of the two gametes. This larger body, which in staining reaction is identical with that of the gametes, is the zygote. In a cyst of twenty-four hours, no spore ducts had begun to appear but the cyst was full of zygotes. The zygotes when fully formed are ellipsoidal in shape, contain many small deeply staining bodies, and possess a rather thin waU (Fig. 234). They develop gradually into spores. The outline becomes more spore-like by the gradual flattening of the ends and the decrease in the number of chromidia while the outer waU increases in thickness. In a cyst of about thirty hours the zygotes have attained the shape of the ripe spores but the content is still that characteristic of the zygote. Prom the thirtieth hour on, the chromidia rearrange themselves and decrease in number by fusion, and the perfection of the mechanism for expelling the ripe spores proceeds. It is probable that the cyst can develop and spores be expelled while within the intestine, possibly resulting in the reinfection of the host and accounting for the enormous numbers of parasites found in some hosts. I have seen cysts dense and opaque, cysts pearl gray and mottled, and even cysts with spore duets well developed and nine in number, all within the body of a freshly caught cricket. The same ad- vanced stages of the cysts of another species have been found in the bodies of freshly opened locusts and also in certain Crustacea. 40 ILLINOIS BIOLOGICAL MONOGRAPHS [250 PAET III Synopsis of the Eugregarine Records of the Myriapoda, Coleoptera, and Orthoptera of the World INTRODUCTION The synopsis and list of parasites which follow were made in order to obtain the essential features of all the known species of eugregarines parasitic in three groups of animals so that in placing on record some twenty odd species which I had found during the last year there would be no danger of redescribing a species under a new name or of describ- ing a new species under a name already used. It is hoped that the synop- sis will be useful to future workers. Species have been included from the whole world and not from the United States only, for many species of protozoa are notably cosmopoli- tan and not restricted to definite areas. The study of gregarines is as yet scarcely begun in the United States and very few species have been found both in the Old "World and in the New, but workers in the United States must be on the lookout for Old World species and should not describe forms new to this country as actually new species without considering the parasites of other regions of the world. Every effort has been made to include in the synopsis all the species mentioned in the literature. Sources of information are as follows: Dufour (1837), KoUiker (1848), Stein (1848), Frantzius (1848), Die- sing (1851), Lankester (1863), Minchin (1903), Labbe (1899), Sokolow (1911), Ellis (1913b), indices of the Zoologischer Anzeiger from 1878 to 1895, cards of the Concilium Bibliographicum from 1895 to date, and current periodicals : Archiv fiir Protistenkunde, Archives de parasitolo- gic, etc., for the past and present calendar years. To a great extent these references have acted as checks on each other although the original sources have not infrequently revealed other species not elsewhere men- tioned. Many of the older species recorded in this synopsis do not ap- pear in Labbe 's Sporozoa. Labbe repeatedly regards as synonyms species which occurred in the same host genus or in allied genera without regard to whether or not the species of parasites were identical. In most instances the species are 251] STUDIES ON GREGARINES— WATSON 41 not the same although the same species or genus of host is involved; such unlike parasites have been separated. For example, Phialoides ornata Leger and Gregarina brevirostra KoUiker were regarded as synonymous because they infect the same host. In some instances Labbe regarded as synonymous species which actually belong together; for ex- ample, Actinocephalus lucanus Stein and Stephaiwphora radiosa Leger, which are identical, the species now being known as Actinocephalus coni- cus (Dufour) Stein. The law of priority has been adhered to strictly and many parasites known by later assigned names have been referred to names given to them many years before, e. g. Actinocephalus conicus which was long known as Actinocephalus lucanus. Labbe in most instances calls such species by the later assigned names in his treatise. In the descriptions of species, well developed sporonts have been taken as the standard except where such have not been described, these rare instances being noted in the synopsis. Shape of the cephalonts is often quite unlike that of the sporonts and thus of no systematic value in diagnosis. "Whenever the epimerite is not mentioned in the literature, as is often the case, the generic determination of the author is based on other characters. The sporonts are often polymorphic and the synopsis records are based on expanded, quiescent, and, as far as known, normal specimens except where the polymorphism is marked. In these instances such facts are noted. In the description of each new species, I have given measurements of only a few large, typical sporonts. These are taken from records of the measurements in most instances of twenty-five or more animals. In most published descriptions the length and width of one sporont only is stated, generally of the largest one observed and the ratios of various parts are based on this one parasite. As the discovery of new species proceeds, I am of the opinion that many will be very similar to others already described and not easily dif- ferentiated from them unless a wide range of measurements and ratios is taken from parasites in different hosts and selections made therefrom for use as a table. This applies in particular to the genus Gregarina, where differences between species appear to be limited. One observer might find the maximum length to be a and the ratio of the two parts as 1 :2. Another worker on the same species might find his largest specimen to be 2a long and the ratio of parts as 1 :3 and describe the species as dif- ferent from the former. A table showing lengths and ratios selected from measurements of many parasites in the same host and from as many .hosts and under as varying conditions as possible (habitat, season, etc.) eliminates the danger of duplication of species. I have differentiated new species in the same genus by the following 42 , ILLINOIS BIOLOGICAL MONOGRAPHS [252 characteristics : Size, both medium and average ; ratio of length of proto- merite to total length ; ratio of width of protomerite to width of deuto- merite ; general shape of the body ; shape of the protomerite ; shape of the deutomerite ; character of the interlocking device ; size and shape of the nucleus ; color and character of the protoplasm ; and the size and shape of the cysts and their method of dehiscence. It is true of many species that the family or generic determination or both are uncertain because important diagnostic features such as the epimerite and spores are often lacking. The correct family can some- times be determined when only one of these factors is present. In some instances the correct genus can be ascribed even though important data are lacking, e. g. the genus Grcgarina, by its biassociative factor and the host involved. If there is any doubt about the position of a given ani- mal, the parasite is placed at the end of the particular genus to which it may belong. In describing the associative gregarines, generally only specific measurements of the primite are given for the proportions of satellite differ considerably within the same species as it happens to be more or less flattened while those of the primite remain fairly constant. The shape given for the posterior end of the deutomerite is that of the satel- lite, where the deutomerite is free at its posterior end ; in the primite it is altered by contiguity with the protomerite of the primite. The species of gregarines indigeneous to each of the three groups are arranged in families, and under each family the genera are placed in alphabetical order. In each genus the species are arranged in chrono- logical order, the oldest first, the latest additions last. New species not hitherto found are described in detail in the groups to which their hosts belong. In. as many instances as possible, the names of the hosts have been checked and corrected to accord with the best authorities. However, this has often been impossible and the names had to be left as in the original citation. Especially is this true of the older species of parasites, many of which have not been found since the original discovery seventy-five years or more ago. The names of the Myriapod hosts have been corrected, those abroad in accordance with Latzel (1884) and those endemic to the United States after Bollman (1893). Ccleopteran literature seems not to be in condi- tion to warrant the finding of synonyms for many of the early described species. For instance, the name by which a beetle is known today will be recorded, but not the name by which it was known some fifty years ago and by which it was called when the parasites infesting it were de- scribed. When names have been corrected to accord with present day 253] STUDIES ON GREGARINES— WATSON 43 knowledge, the older name is placed in parenthesis after the now ac- cepted name. The spelling of the name of the diplopod Julus as given by Linnaeus (1766) has been used thruout wherever the word appears, whether in the name of the host or in the name of a species of parasite where the name is used as a prefix. The lulus of some authors is, then, disregarded in the nomenclature of the species. A Brief Synopsis of the Families and Genera of the Tribe Cephalina (Delage) OF THE Suborder Eugregarinae (Leger) This synopsis is based on the classification of Minchin (1903, 1912) and Poche (1913)- Subphylum Sporozoa Leuckart 1879:241. Class I. Telosporidia Schaudinn. Sporulation ends the life of the individual. Order i. Gregarinida Biitschli 1882 :S03. Reproduction by spore forma- tion only or by both spore formation and budding. Suborder l. Schizogregarinae Leger. 2. Eugregarinae Leger. Reproduction limited to spore for- mation. Spores octozoic. Tribe i. Acephalinae KoUiker (Monocystoidae Poche). 2. Cephalinae Delage 1896:269. Eugregarinae with an epimerite at some stage in the life history. Body usually divided by septum into protomerite and deu- tomerite. Spores with two coats. Mainly parasitic in the gut of arthropods. Family l. Didymophyidae Leger 1892:105. In associations of two or three. No septa in satellites. Genus i. Didymophyes Stein 1848:186. Characters of the family. Epimerite a small pointed papilla, cyst dehiscence by simple rupture. Spores ellip- soidal. Family 2. Gregarinidae Labbe 1899:9. Associative or soli- tary, satellite with septum. Epimerite symmet- rical, simple. Cysts with or without spore ducts. Genus 2. Gregarina Dufour 1828:366. Biassociative. Epimerite small, globular or cylindrical. Spores dolioform to cylindrical. Cysts dehisce by spore ducts. Genus 3. Hirmocystis Labbe 1899:12. Associations of from two to twelve or more. Epimerite a small cylindrical papilla. Cysts dehisce by simple rupture. Spores ovoidal. Genus 4. Hyalospora Schneider 1875 :583. Biassociative. Epimerite a simple globular knob. Cysts de- hisce by simple rupture. Spores ellipsoidal. Endoplasm yellow-orange. 44 ILLINOIS BIOLOGICAL MONOGRAPHS [254 Genus S- Cnemidospora Schneider 1882:446. Solitary. Epimerite not known. Anterior half of pro- tomerite gray, posterior half yellow-green. Dehiscence of cysts by simple rupture. Spores ellipsoidal. Genus 6. Euspora Schneider 1875:582. Biassociative. Epimerite not known. Cysts dehisce by sim- ple rupture. Spores prismatic. Genus 7. Sphaerocystis Leger 1892:115. Protomerite only in young stages. Solitary, subspherical. Dehiscence by simple rupture. Spores ovoidal. Genus 8. Gamocystis Schneider 1875:587. Protomerite only in young stages. Associative. Sporula- tion partial, with spore ducts. Spores cylin- drical. Genus 9. Frenzelina Leger and Duboscq 1907 :773. (Cepha- loidophora Mawrodiadi 1908:101). Biasso- ciative. Epimerite not known. Cysts de- hisce by simple rupture. Spores ovoidal, with dark equatorial line. Intercellular develop- ment. Genus 10. Uradiophora Mercier 1912:198. B'i- or tri- associative. Epimerite simple style, forked at end. Cysts dehisce by simple rupture. Spores dolioform. Genus 11. Leidyana Watson 1915. Solitary. Epimerite a simple globular sessile knob. Dehiscence by spore ducts. Spores dolioform. Family 3. Dactylophoridae Leger 1892:165. Epimerite com- plex. Sporonts solitary. Cysts dehisce with lateral pseu- docyst or by simple rupture. Spores elongate, cylindrical or ellipsoidal. Genus 12. Dactylophorus Balbiani 1889:41. Protomerite dilated laterally with peripheral digitiform processes. Sporonts solitary. Spores in chains obliquely. Genus 13. Nina Grebnecki 1873: — . Protomerite formed of two long narrow horizontal lobes fused and upturned spirally at one end. Periphery set with teeth from which project long slender filaments. Spores in chains obliquely. Genus 14. Trichorhynchus Schneider 1882:438. Epime- rite a very long slender neck with dilation on surface. Lateral pseudocyst for dehiscence. Spores cylindrical or ellipsoidal, not in chains. 255] STUDIES ON GREGARINES— WATSON 45 Genus 15. Echinomera Labbe 1899:16. Epimerite an ec- centric cone with eight or more short digiti- form processes from sides. Dehiscence by- simple rupture. Spores cylindrical, in chains. Genus 16. Rhopalonia Leger 1893:1285. No protomerite in sporonts. Epimerite a subspherical cushion with ten or more short thick digitiform pro- cesses. Pseudocyst. Spores cylindrical. Genus 17. Acutispora Crawley 1903 :632. Epimerite not seen. Pseudocyst. Spores biconical, thick blunt endosporic rod at each end. Genus 18. Metamera Duke 1910:261. Epimerite sub- conical, apex eccentric, surrounded by numer- ous branched digitiform appendages. Dehis- cence by simple rupture. Spores biconical. Family 4. Actinocephalidae Leger 1892:166. Sporonts soli- tary. Epimerites varied. Cysts dehisce by simple rupture. Spores irregular, biconical or cylindro-biconical. Genus 19. Actinocephalus Stein 1848:196. Epimerite small, sessile or on a short neck, with 8 or 10 short sharp spines or simple bifurcate digiti- form processes. Spores biconical. Genus 20. Geneiorhynchus Schneider 1875 :S94. Epime- rite a tuft of short bristles set at the apex of a long slender neck. Spores cylindro-bicon- ical. Genus 21. Pyxinia Hammerschmidt 1838:357. Epimerite a flat crenulate crateriform disc from center of which rises a short or long style. Spores biconical. Genus 22. Beloides Labbe 1899:27. Epimerite a spiny globule with a long apical style set on a short stout neck. Spores biconical. Genus 23. Phialoides Labbe 1899 :24. Epimerite a broad cushion with peripheral row of teeth and a thickened ■ collar placed on a long slender neck. Spores biconical. Genus 24. Legeria Labbe 1899 :24. Epimerite not known. Protomerite dilated and massive. Septum convex upward. Spores cylindro-conical. Genus 25. Coleorhynchus Labbe 1899:23. Epimerite not known. Protomerite a round shallow disc depressed in center. Septum convex upward. Spores biconical. Genus 26. Bothriopsis Schneider 1875 :S96. Epimerite an ovoidal structure with 6 or more long slender filaments. Protomerite very large, septum convex upward. Spores biconical. 46 ILLINOIS BIOLOGICAL MONOGRAPHS [256 Genus 27. Asterophora Leger 1892:129. Epimerite a thick horizontal disc with a milled border and a stout style projecting from center. Spores cylindro-biconical. Genus 28. Schneideria Leger 1892:153. (Rhabdocystis Boldt 1910:289). Epimerite like that of As- terophora. Style shorter, no protomerite in sporonts. Spores biconical. Genus 29. Stictospora Leger 1893:129. Epimerite spheri- cal, centrally depressed, armed with a dozen backwardly directed mucrones set on a short neck. Spores biconical, slightly curved. Genus 30. Stylocystis Leger 1899:526. Epimerite a re- curved sharply pointed cone. Spores biconical. Genus 31. Steinina Leger and Duboscq 1914:352. Epime- rite a short mobile digitiform process changing into a flattened button. Spores biconical. Genus 32. Taeniocystis Leger 1906:307. Epimerite a small sphere set with 6 or 8 recurved hooks. Deutomerite divided by septa into numerous linear segments. Spores biconical. Genus 33. Discorhynchus Labbe 1899:20. (Sycia Leger 1892:52). Epimerite a large globular struc- ture with a thin collar around base. Short stalk. Spores biconical, slightly curved. Genus 34. Amphoroides Labbe 1899:20. Epimerite a globular sessile papilla. Protomerite cup shaped. Spores curved. Genus 35. Pileocephalus Schneider 1875:591. Epimerite a lance-shaped or simple cone. Spores bi- conical. Genus 36. Anthorhynchus Labbe 1899:19. Epimerite a large fluted flattened button. Spores ovoidal, pointed. Genus 37. Sciadophora Leger 1899:18. Epimerite large, compressed laterally, peripherally crenulate. Protomerite bears numerous backwardly di- rected mucrones. Spores biconical. Genus 38. Hoplorhynchus Carus 1863 :570. Epimerite a flat button with 8 or 10 digitiform processes carried on a long collar. Spores biconical. Genus 39. Amphorocephalus Ellis 1913 :462. Epimerite dilated in middle, terminating in concave per- ipherally fluted disc at anterior end. Spores not known. Protomerite constricted across middle. Family 5. Acanthosporidae Leger 1892:167. Sporonts soli- tary, epimerite simple or appendicular. Dehiscence by simple rupture. Spores with equatorial and polar spines. 257] STUDIES ON GREGARINES— WATSON A7 Genus 40. Acanthospora Leger 1892:145. Epimerite a simple ' conical papilla. Spores biconical or ovoidal with row of equatorial spines and a tuft of four spines at each pole. Genus 41. Corycella Leger 1892 :i44. Epimerite globular with 8 large recurved hooks. Spores biconi- cal, 4 spines at each pole. Genus 42. Ancyrophora Leger 1892:146. Epimerite a globule with 5 or 10 backwardly directed di- gitiform processes. Spores biconical with equatorial and polar spines. Genus 43. Cometoides Labbe 1899:29. Epimerite a spher- ical button with long slender filaments. Spores cylindro-biconical, with polar and two rows of equatorial spines. Family 6. Menosporidae Leger 1892 :i68. Sporonts solitary. Epimerite a large cup bordered with hooks and placed on a long slender collar. Cysts dehisce by simple rupture. Spores crescentic, smooth. Genus 44. Menospora Leger 1892:168. Characters of the family. Family 7. Stylocephalidae Ellis 1912 :2s. Sporonts solitary, epimerites varied. Nucleus ovoidal. Dehiscence by pseu- docyst. Spores irregularly shaped, brown or black, in chains. Genus 45. Stylocephalus Ellis 1912 :2S. Epimerite a di- lated papilla at end of a long slender neck. Cyst covered with small papillae and indenta- tions. Spores hat-shaped. Genus 46. Sphaerocystis Labbe 1899:32. Epimerite a small sphere or ellipsoidal body at end of a long slender neck. Genus 47. Lophocephalus Labbe 1899 :3i. Epimerite a large sessile flattened crateriform disc, the periphery crenulate and set at base with nu- merous short upwardly directed digitiform processes. Spores hat-shaped, black. Genus 48. Cystocephalus Schneider 1886:99. Epimerite a large lance-shaped papilla set on a short stout cylindrical collar. Spores irregularly shaped. Family 8. Stenophoridae Leger and Duboscq 1904:361. De- velopment intercellular. Sporonts solitary. Epimerite absent or a simple structure. Cysts dehisce by simple rupture. Spores ovoidal with equatorial line. Not extruded in chains. Genus 49. Oocephalus Schneider 1886:101. Epimerite a spherical button upon a short conical neck. Spores not known. 48 ILLINOIS BIOLOGICAL MONOGRAPHS [258 Genus 50. Stenophora Labbe 1899:15. Characters of the family. Confined to Diplopoda. GENERA OF UNCERTAIN POSITION Genus 51. Ulvina Mingazzini 1891 :23s. Genus 52. Nematoides Mingazzini 1891 :233. Dicystid, no septum in sporonts. Epimerite forked, situ- ated on a long collar. Genus S3. Ganymedes Huxley 1910:155. Associative, epi- merite not known. Complete fusion of two individuals into one cytoplasmic mass. Cup at posterior end to aid in attachment. Spores unknown. Liver of crustaceans. Genus 54. Agrippina Strickland 1912:108. Sporonts soli- tary, epimerite a circular disc armed with digitiform processes on periphery, short neck. Spores ellipsoidal. POLYCYSTID GEEGARINBS IN THE DIPLOPODA* NAME OF PARASITE Stenophora larvata (Leidy) Ellis Stenophora polydesmi (Lankester) Watson Stenophora julipusilli (Labbe) Crawley Stenophora juli (Frantzius) Labbe Stenophora dauphinia Watson Stenophora spiroboli Crawley Stenophora fontaria (Crawley) Watson Stenophora brolemanni Leger and Duboscq Stenophora nematoides Leger and Duboscq Stenophora varians Leger and Duboscq Stenophora producta Leger and Duboscq Stenophora aculeata Leger and Duboscq Stenophora polyxeni Leger and Duboscq Stenophora silene Leger and Duboscq Stenophora chordeume Leger and Duboscq Stenophora Corsica Leger and Duboscq Stenophora robusta Ellis NAME OF HOST Spirobolus spinigerus Wood Fontaria virginensis (Drury) Julus and Parajulus Julus sabulosus (L.) Julus boleti C. Koch Julus mediterraneus Latzel Juhis boleti C. Koch Julus fallax Meinert Spirobolus sp. Fontaria sp. Polydesmus sp. Blaniulus hirsutus Brol. Brachydesmus superus Latzel Brachyiulus pusillus lusitanus Verb. Strongylosoma italicum Latz. Schizophyllmn corsicum Brol. Julus varius Fabricus Craspedosoma rawlinsii simile Verh. Polyxenus lagurus (L.) Lat. Lysiopetalum foetidissimum Savi Chordeuma silvestre C. Koch Craspedosoma legeri Brol. Parajulus venustus Wood Orthomorpha gracilis (C. Koch) Orthomorpha sp. *The parasites are arranged in chronological order, under each genus. 259] STUDIES ON GREGARINES— WATSON 49 Stenophora cockerellae Ellis Stenophora elongata Ellis Stenophora impressa Watson Stenophora lactaria Watson Stenophora diplocorpa Watson Cnemidospora lutea Schneider Amphoroides polydesmi (Leger) Labbe Amphoroides calverti (Crawley) Watson Parajulus sp. Orthomorpha coarctata (Sauss.) Parajulus impressus (Say) Callipus lactarius (Say) Euryurus erythropygus (Brandt) Glomeris sp. Polydesmus complanatus (L.) Polydesmus dispar Silvestri Callipus lactarius (Say) STENOPHOEA LARVATA (Leidy) Ellis [Fi^re 1] 1849 1851 1853 1863 1875 1899 1903 1904 1913 Gregarina larvata Gregarina larvata Gregarina juli marginati Gregarina juli Stenocephalus juli Stenophora juli Stenophora juli Stenophora iulimarginati Stenophora larvata Leidy Diesing Leidy Lankester Schneider Labbe Crawley Leger and Duboscq Ellis 1849 :232 1851 :553 1853 :237 1863 :94 1875 :584-5 1899 :15 1903 :51 1904:362 1913a :286 Stenophora: Sporonts solitary, elongate. Maximum length 800/*, maximum width 23/*. Ratio length protomerite : total length : : 1 : 20 ; width protomerite : width deutomerite : : 1 : 2. Protomerite small, subglobular, slightly flattened top and bottom, a flat circular papilla at apex with an apparent pore in center. A conspicuous con- striction at septum. Deutomerite elongate-cylindrical, tapering gradu- ally from center to an acute but bluntly pointed cone. Endocyte of protomerite clear, granular; of deutomerite dense and opaque. Nucleus small, spherical. Taken at Philadelphia, Pa. Host: Spirobolus spinigerus Wood {Julus marginatus Say) . Habitat: Intestine. This species was observed by Leidy in 1849 and was the first gre- garine he observed. His general statement regarding the parasite is quoted here nearly in full on account of its quaintness. "Gregarina is probably the larva condition of some more perfect animal, but in the Ii6 individuals of Julus virhich I have examined, I have not been able to detect any form which could be derivable from it. Creplin doubts its animal- ity. ... I detected movements of an animal character, and this led me to seek for muscular structure, which resulted in the discovery of the longitudinal lines of the inferior cell. These escaped the observation of Siebold . . . In the state in which Gregarina is found, it would probably hold a rank between the Trematoda and Trichina, the lowest of the Nematoidea." To Leidy, then, must be attributed the discovery of the longitudinal £0 ILLINOIS BIOLOGICAL MONOGRAPHS ■ [260 striations in the epicyte and it is interesting to note that he discovered them during his first observations on the gregarines. Leidy renamed the species four years later from the host in which it was found. Lankester (1863:94), in a classification of the gregarines, grouped three of Leidy 's forms: O. larvata, G. juli marginati, and G. juli pusUli, together with Gregarina- juli Prantz. under the name of the latter, ap- parently because they were all parasites and the only known parasites of the same diplopod. Schneider (1875:585) disregarding the rule of priority united Gre- garina juli marginati and a species which he discovered under the name Stenocephalus juli (Leidy) . His remarks are as follows : "Cette espece est commune et me parait etre identique a celle decrite par Leidy sous le nom de Gregarina juli marginati. Dans ce cas elle serait probable- ment repandue chez les differentes especes du genre Julus, puisqui'on la con- naitrait deja chez trois d'entre elles. . . . L'espece est legerment polymorphe elle est tantot tres-allongee et relativement etroite, tantot remarquablement mass- ive; mais son protomerite demeure toujours identique a lui-meme et suffit ample- ment au diagnostic." Leidy gave no measurements of his species and Schneider based the identity of the two forms on the similarity of Leidy 's figures with his ma- terial . It is true that in general shape the two are very similar but the protomerites differ slightly and the color differs markedly. Leidy 's spe- cies is white; Schneider's yellow' to yellow-orange. Because of these dis- similarities, the two forms should be separated. Labbe (1899 :15) changed the name of the genus Stenocephalus of Schneider to Stenophora. Crawley (1903a; 634) did not consider the two species identical. His words are as follows : "There is a good deal of confusion regarding the gregarines occurring in the Diplopod family Julidae. These gregarines all bear a certain amount of resemblance to one another, and it has been usual to relegate all of them to the species ^itenophora juli Frantz. Leger and Duboscq (1903) have recently shown that such a procedure is not warranted for the fauna of Corsica and the case is certainly the same for that of the eastern United States. The Julidae of this region are infected with certainly two and possibly three species of Stenophora, while the classic S. juli apparently does not occur." Leger and Duboscq (1904:361-2) take up the same discussion in their history of the Stenophoridae as follows : "Leidy fit connaitre une Gregarine assez particuliere, parasite de I'intestin de lulus marginatus Say. II I'appela d'abord (1851) Gregarina larvata, puis changea son nom en celui de Gregarina iuli marginati dans un travail posterieur (1853) ou il decrit une autre Gregarine, G. iuli pusilli, parasite d'un petit iule . . . qui n'est pas lulus pusillus Leach. 261] STUDIES ON GREGARINES— WATSON 51 Ray Lankester (1863) reunit les deux Gregarines de Leidy au Stenophora Mi de Frantzius, et cette synonymie fut admise par tous les auteurs qui suivirent. Schneider (1875) le premier, decrivit avec precision la Gregarine parasite des lulus sabulosus et lulus terrestris. II nota I'absence d'epimerite, la striation de I'epicyte tres marquee sur les 2 segments, la coloration jaune ou orangee de Tentocyte et le caractere des spores. Ces particularites lui firent creer le genre Stenocephalus pour cette Gregarine qu'il identifia a la Gregarine decrite par Leidy dans Spiroholus marginatus Say. II I'appela Stenocephalus iuli Leidy, nonobstant les regies de la nomenclature. Stenocephalus iuli devint ainsi la seule Gregarine des lules et Gabriel (1880) y rapporta de lui-meme sa Gregarina paradoxa. Dans les Sporozoa du Tierreich (iSgg) Labbe consacra les habitudes prises en ne reconnaissant pour Gregarine parasite des lules que le Stenophora iuli. II se contenda de remplacer le nom generique de Schneider par celui de Stenophora, le nom de Stenocephalus ayant ete attribue anterieurement a un genre d'Hemipteres. Howard Crawley (1903) etudiant les Gregarines des lules et Paraiulus des Etats-Unis, rapporta les diverses especes de Leidy au Stenophora iuli, tout en creant une nouvelle espece pour un Stenophora d'un Spirobolus. Mais, dans un travail sue la faune de Corse (1903) nous avons montre que les Stenophora etaient representes par plusieurs especes reconnaissables a la seule vue de cephalin. Notre facon de voir est adoptee par Crawley dans un second travail (1903a) et il restaure le Stenophora iulipusilli Leidy en soutenant que que le classique Steno- phora iuli n'existe pas en Amerique. Les especes americaines de Stenophora se trouvent ainsi bien separees du Stenophora iuli (Frantzius) Schneider. Nous (1903a) en avons detache egale- ment un certain nombre de Stenophora des Diplopodes de Corse ou de Provence." Stenophora larvata has not been found since Leidy 's discovery of the species and its validity must be questioned until his work is substantiated by rediscovery of this parasite. STENOPHOEA POLYDESMI (Lankester) Watson [Figures 2, 3, 4] 1853 Gregarina polydesmi virginiensis Leidy 1853 :238 1863 Gregarina polydesmi Lankester 1863 :94 1899 Amphoroides polydesmi Labbe 1899 :20 1903 Gregarina polydesmivirginiensis Crawley 1903 :45-46 1913 Amphoroides polydesmivirginiensis Ellis 1913b :274 1916 Stenophora polydesmi Watson (This paper) Stenophora: Sporonts solitary, elongate. Length 400-900/**; width of deiitomerite through widest part 25 to 60/t. Eatio length proto- merite : total length : : 1 : : 15 to 1 : 17 ; width protomerite : width deutomerite : : 1 : 1.5 to 1 : 2 in normally extended individuals. Pro- *Crawley (1903:46) gives 400jn as a maximum while Leidy gives goOfji,. 52 ILLINOIS BIOLOGICAL MONOGRAPHS [262 tomerite subglobular to elongate, length twice the width. Slight con- striction, if any, at septum. Protomerite as wide or wider than deuto- merite at the septum. Deutomerite cylindrical, well rounded at poste- rior end. Endocyte tranluscent. Nucleus visible in vivo, ellipsoidal, one spherical karyosome. Cyst and spores unknown. Taken at Philadelphia and Wyncote, Pa., and Raleigh, N. C. Host: Fontaria virginiensis (Drury) (Polydesmus virginiensis). Habitat: Intestine. This species was described by Leidy (1863:238). Leger (1892:132) described a species, Amphorella polydesmi, from the intestine of Polydesmus complanatus (L.). He created for the species a new genus, characterized by the presence of a short circular cup-like protomerite. Labbe (1899:20) united the A. polydesmi of Leger and G. polydes- mi virginiensis of Leidy as one species and because Amphorella was in- valid, called the genus Amphoroides and the species Amphoroides poly- desmi (Leger). But the protomerite of G. polydesmA virginiensis does not coincide in shape with that of the genus Amphoroides, for it is subglobose and bears no indication of a cup-like depression which is characteristic of the latter genus; therefore it must be placed elsewhere. The three following fac- tors coincide with those of the genus Stenophora, viz: a) subglobose pro- tomerite, b) relative length of protomerite as compared with total length, c) solitary sporonts. The spores and the epimerite still remain undis- covered and until they are found the generic determination is, of course, not absolute. Crawley (1903:45-6) called the species 6. polydesmivirginiensis (Leidy), but in a later paper (1903a :640) he included it in a group of doubtful forms, all of which, however, he placed in the genus Gregarina. Ellis (1913b :274) erroneously attributes to Crawley the assignment of the species name Amphoroides polydesmivirginiensis. It is Ellis him- self at this point who names the species A. polydesmivirginiensis (Leidy). He offers no explanation therefor. For the reasons given above, the species is now removed from the genus Amphoroides and placed in the genus Stenophora, the name now standing Stenophora polydesmi (Lankester) "Watson. The trinomial of Leidy was shortened to a binomial by Lankester and this binominal must stand. This is a well defined species, having been found and drawn by Crawley in 1903 and taken from the host in which it was originally found. The writer has examined a half dozen specimens of this diplopod taken at Urbana, without finding an instance of infection. 263] STUDIES ON GREG ARINES— WATSON S3 STENOPHORA JULIPUSILLI (Labbe) Crawley [Figure 6] 1853 Gregarina juli pusilli Leidy 1853 :238 1863 Gregarina juli Lankester 1863 :94 1899 Gregarina julipusilli Labbe 1899:35 1903 Stenophora julipusilli Crawley 1903a :634-5 1904 Stenophora iulipusilli Leger and Duboscq 1904:362 Stenophora: Sporonts solitary, elongate, rather stout. Maximum length 400/*, maximum width not given. Ratio length protomerite : total length : : 1 : 9 in adults ; ratio width protomerite : width deuto- merite : : 1 : 1.5. Shape protomerite conical with a rather sharp apex, widest below median portion, papilla with an apparent pore at anterior end, deep constriction at septum. Slightly broader than high. Deutome- rite irregularly cylindrical, four times as long as broad, sometimes widest through middle, sometimes posterior to middle. Endocyte very dense in adults. Granules of protomerite different from those of protomerite. Nucleus spherical and large, attaining half the width of deutomerite. Contains a large karyosome. Cyst and spores unknown. Taken at Philadelphia, Pa. Hosts Julus sp. and Parajulus sp. Habi- tat : Intestine. This parasite was found and described by Leidy as Gregarina juli- pusilli. Both figures he gives appear to be those of immature specimens (see Pig. 5). From Leidy 's data alone, I should consider the species invalid. Crawley (1903:51) includes both G. juli pusilli and G. juli margi- nati with the classic Stenophora juli Frantzius under the name of the latter. That this determination was erroneous Crawley later discovered and (1903a :634-5) he separated the three species: "This species is easily separated from 5". juli by the size of the protomerite. In 6". juli the length of the protomerite, according to the figures given by Schnei- der (1875) makes up only about 6% of the total length. In S. julipusilli this proportion increases to 10%' in the adults and 15% in the young." Stenophora julimarginati therefore stands as a separate, well de- fined species ; the species described as Gregarina juli pusilli Leidy was renamed by Crawley as Stenophora julipusilli (Leidy). Crawley's words concerning the confusion of names are as follows : "There is a good deal of confusion regarding the gregarines occurring in the Diplopod family Julidae. These gregarines all bear a certain amount of 54 ILLINOIS BIOLOGICAL MONOGRAPHS [264 resemblance to one another, and it has been usual to relegate them all to the species Stenophora j'uli Frantzius. . . . The Julidae of this region are infected with certainly two and possibly three species of Stenophora, while the classic S. juli apparently does not occur. Of these species, one is unquestionably the form described by Leidy (1853) as Gregarina julipusilli. As indicated by the specific name, Leidy considered its host to be Julus pusillus Say. According to Bollman (1887) this milliped,' correctly Julus minutus Brandt does not occur in Pennsylvania, and it may be that Leidy was mistaken in his identification. This matter is not, however, of any great importance, and the specific name of the gregarine must stand. Leidy spelled the specific name of the host pusullus, whereas Say's memoir (1821) renders it pusillus, which spelling will be used for the name of the gregarine." Leidy 's original spelling of the host name (1853 :238) pusillus is the correct one and the last remark of Crawley is uncalled for. The correct name of the diplopod, according to Bollman (1893), is now Nemasoma minutum (Brandt). Since Leidy 's description and figures are so inadequate and even his determination of the host possibly in error, there was no valid rea- son for Crawley's having retained the specific name julipusUU when he redescribed the species (1903a: 634-5). Leger and Duboscq in the citation just given mention (1904) 8. iulipusilli (Leidy) Crawley as a distinct species (note the last quotation) . In the specific diagnosis, given at the beginning of this species, Leidy 's description was excluded. It is as follows: "Gregarina Juli pusilli. White, translucent, oval. Cephalic sac hexahedral, with the sides rounded or forming a double cone, base to base, with the upper apex subacute or truncated in younger individuals. Posterior sac robust, oval; granular contents, fine, translucent; interior corpuscle, globular, transparent; nucleus transparent, without nucleolus. Whole length from i 1500 in. to I 275 in. Breadth of largest I 500 in. Diameter of head of largest I 1500 in. Hab. Intes- tine Julus pusillus." The name of this species must be a binominal and since Labbe was the first to give such a name to the particular species here designated, the species naine becomes Stenophora julipusilli (Labbe) Crawley. 265] STUDIES ON GREG ARINES— WATSON 55 STENOPHORA JULI (Frantzius) Labbe [Figures 7 and 8] 1848 Sporadina Juli Frantzius 1848 :195 1851 Gregarina juli Diesing 1851:15 1863 Gregarina juli Lankester 1863 :94 1875 Stenocephalus juli Schneider 1875:584-5 1880 Gregarina paradoxa Gabriel 1880:371 1899 Stenophora juli Labbe 1899 :15 1903 StenopJwra juli Crawley 1903 :51 1904 Stenophora iuli Leger and Duboscq 1904:363-8 Stenophora: Sporonts solitary, elongate. Dimensions not given. Ratio length protomerite : total length : : 1 : 20 (approximately) ; ratio width protomerite : width deutomerite :: 1 : 2. Protomerite small, cylindrical at base, sharply conical above, little wider than high, a small papilla with an apparent pore at apex. Deutomerite elongate, slightly wider in anterior third than elsewhere, tapering gradually to an acute but blunt cone. Endocyte yellow to orange. Nucleus spherical, diameter half that of the deutomerite at its widest part, containing one large karyosome. Cysts dehisce by simple rupture. Spores fusiform with equatorial line. Taken at Roscoff, France. Hosts: Julus sabulosus (L.) ; Julus fal- laoo Meinert (Julus t err estris). Habitat: Intestine. Stenophora juli has been the source of more confusion and of greater discussion than any other gregarine parasitic in the diplopods. The too concise descriptions and the lack of any measurements of the animals by the earlier writers have led later workers to place a number of different parasites in this same group and to regard them all as Stenophora juli. Frantzius' beautiful drawings are accompanied by no description beyond the statement that the parasite was found in Julus. Diesing called the parasite Gregarina juli Frantzius. His descrip- tion is as follows : "Proboscis? Receptaculus capitellatum acutum brevissimum. Corpus longum fusiforme. Hab. Julus terrestris . . ." Lankester (1863:94) relegated to this species the following: Grega- rina juli pusilli Leidy, G. juli marginati Leidy, and G. larvata Leidy, all of which belong elsewhere, the last two being synonymous. 56 ILLINOIS BIOLOGICAL MONOGRAPHS [266 Schneider (1875:584-5) described a species as Stenocephalus juli from the intestine of Julus sabulosus and what he regarded as Julus ter- restris*. He considered his species as related if not synonymous with a species described by Leidy in 1853 as Gregarina juli marginati. His words are these : "Cette espece est commune et me parait etre identique a celle decrite par Leidy sous le nom de Gregarina juli marginati. Dans ce cas, elle serait probable- ment repandue chez les differentes especes du genre Julus, puisqui'on la con- naitrait deja chez trois d'entre elles . . . L' espece est legerment polymorphe; elle est tantot tres-allongee et relativement etroite, tantot remarquablement mass- ive; mais son. protomerite demeure toujours identique a lui-meme et scuffit ample- ment au diagnostic." Schneider overlooked the color factor in correlating the two species. Leidy described his O. juli marginati as "opaque, white." Schneider's Stenocephalus juli has the endocyte colored yellow or orange. Schneider gives no dimensions, but from the figure the proportions of his species agree perfectly with those of Leidy 's species. The protomerites of the two species are slightly different in shape in the character of the papilla at the apex. The papilla in Leidy 's species is large and flattened and the apparent pore is widest at the apex, narrowing as it approaches the en- docyte; in Schneider's figure the papilla is smaller, more conical, either sharp or blunt at the end, slender in the middle, broadening at the base next the endocyte. While the two species are obviously closely related, I am of the opin- ion that they are not identical. Crawley (1903a :634) says "the classic Stenophora juli apparently does not occur" in the United States and to date, 1915, it has not been described from this country. If Schneider had given a set of dimensions for his species, that were identical with those of Leidy, the personal equation might have been con- sidered to such an extent as to eliminate the color consideration and the variation in the two protomerites. Leidy 's Gregarina julu marginati is thus seen to be distinct from Schneider's S. juli and stands today as Stenophora larvata (Leidy) Ellis. In 1880, Gabriel (p. 371) mentioned a species which he calls Grega- rina paradoxa and says it is identical with G. juli (Frantz.) Schn. Neither description nor drawings accompany this statement and the rea- son for giving the species a new name, if it be S. juli, is not apparent. *Leger and Duboscq (1904:364) say that /. fallax Mein. (/. albipes C. Koch) is probably the /. terrestris of Schneider. 267] STUDIES ON GREGARINES— WATSON 57 Labbe (1899:15) unites under the name S. juli (Frantz.) Schn. all of the following : 1848 Gregarina juli Frantzius 1875 Stenocephalus juli Schneider 1851 Gregarina larvata Leidy 1853 Gregarina juli marginati Leidy 1880 Gregarina paradoxa Gabriel Why Labbe regards them all as synonymous, he does not state. They appear to be alike only in that they are all parasites of the same diplopod, Julus. "With the exclusion of the last three*, the species stands as con- taining the original G. juli Frantz. and Stenocephalus juli Schn. The ratios obtained from figures given by Frantzius and Schneider are almost identical. Neither author gives any dimensions, so the animals may agree not at all in actual size. The character of the endoplasm, its granu- lar content and color, may differ considerably. Leger and Duboscq give a detailed account of the various species which have been confused in the literature. For the entire quotation, see under the heading Stenophora larvata (Leidy) Ellis. From a lack of positive evidence to the contrary, the two species Gregarina juli Frantz. and Stenocephalus juli Schn. stand as a single species, now called Stenophora juli (Frantzius) Schneider. Leger and Duboscq (1904:363-8) described a parasite as Stenophora juli and considered it synonymous with the S. juli above. The animal which they described differs greatly from the classic S. juli in shape of all its parts, in its proportions, the dedsity of its endoplasm, and in the shape of its nucleus ( ! ) . A detailed consideration of these factors is taken up under Stenophora dauphinia. STENOPHORA DAUPHINIA Watson [Figure 9] 1904 Stenophora juli Leger and Duboscq 1904 :363-8 1916 Stenophora dauphinia Watson (This paper) Stenophora : Sporonts solitary, elongate. Total length 250 to 300/*. Width 19/x. Ratio length protomerite : total length : : 1 :10 ; width protomerite : : 1 : 0.9. Protomerite dilated in posterior two-thirds, separated from anterior part by a deep circular constriction. Apex broadly conical, papillate anterior end, with an apparent pore. Deuto- merite cylindrical, attaining ten times the length of the protomerite. *The third and fourth are synonymous being now S. larvata; the fifth is synonymous with S. juli. 58 ILLINOIS BIOLOGICAL MONOGRAPHS [268 Width nearly the same throughout and ending in a blunt rounded poste- rior extremity. Endoeyte not described. Nucleus ellipsoidal, 1.7 times as long as wide. Cysts spherical, 250/* in diameter. Spores regularly ovoidal, epispore present. Equatorial line on spores. Taken at Turin, Italy, and in Dauphine, France. Hosts: Julus mediterraneus Latzel (Schizophyllum mediterraneum Latz.) ; Julus bo- leti C. Koch (Julus londinensis Mein.) ; Julus fallax Mein. (Julus albipes C.Koch). The authors described a parasite found in the same host as that upon which Schneider based his observations in his discovery of Grega- rina juli (Prantzius). The species named by Schneider as the host of his parasites was Julus terrestris (Linnaeus) Porat but Leger and Duboscq observed that this species does not occur in France (1904:363). "Nous decrirons d'abord Stenophora iuli (Frantzius) Schneider, qui nous a fourni de bons documents pour I'etude du developpement des Stenophorides, at dont il importe de preciser la diagnose. Nous entendons par Stenophora iuli (Frantz.) Schneider le parasite de Schizophyllum sahulosum L. qui correspond a la description de Schneider. Cet auteur trouvait aussi Stenophora iuli dans lulus terrestris, mais lulus terrestris L. n'est pas une determination. Depuis un siecle, les anastomistes appellent de ce nom tous les lules qui sont de coleur noire, et le veritable lulus terrestris (Linne) Porat ne parait pas exister en France. . . Et en effet, nous voyons dans un certain nombre d'lules, une Gregarine bien voisine du parasite de Schizophyllum sabulosum L. Citons notamment parmi les hotes de Stenophora iuli, Schizophyllum mediterraneum Latz. de la Tourraine, lulus londinensis Mein. de la Tourraine, lulus albipes C. K. du Dauphine." These authors base their observations on the parasites found chiefly in Julus albipes. In Julus sabulosus the gregarine attains a length of 450/i; in /. fallax Mein. and J. boleti C. K. of 300/t. Besides the elon- gate form, they mention a globular form nearly as wide as long, and reaching 130/t in length. They do not illustrate this form. The elongate sporont, only, is figured. The authors do not describe the shape of the various parts and make no comparison ■ of their form with the classic 8. juli, basing their identification rather on a similarity of hosts than of parasites. 269] STUDIES ON GREGARINES— WATSON 59 The data and figures given by Leger and Duboscq (1904) and by Schneider (1875) compare as follows: Schneider Total length Total width Ratio 1. prot : total 1 Ratio w. prot : w. deut Shape protomerite I : 20 I : 2 L£ger and Duboscq 4S0 max. 10 0.9 Apex papillate, with pseudo-canal, lower part cylindrical, upper part broadly conical, no con- striction in protomerite. Shape deutomerite Nucleus Shading in figure Irregularly cylindrical, tapering from anterior third to a sharp but rather broad cone. Twice as wide at shoulder as at protomerite. Spherical. One large karyosome. Protomerite Dark Deutomerite Dark Apex papillate with pseudo- canal, lower part broader than upper and separated from above by a deep cir- cular constriction. Deep constriction at septum. Regularly cylindrical, of ap- proximately same width throughout, tapering slightly at posterior tip. Slightly narrower than protomerite. Ellipsoidal (l : 1.7) with one large karyosome. Very light Dark The proportions of the body dimensions, the shape of the two pro- tomerites, and the shape of the two nuclei indicate at a glance that more than one species is under consideration and the species described by Leger and Duboscq should be renamed. I therefore designate it Steno- phora dauphinia. STENOPHORA SPIROBOLI Crawley [Figure 10] 1903 Stenophora spiroboli Crawley 1903:51 1903 Cnemidospora spiroboli Crawley 1903a :638 1913 Stenophora spiroboli Ellis 1913b :286 Stenophora : Sporonts solitary, elongate. Maximum length 1000/x ; width not given. Ratio length protomerite : total length :: 1 : 32; width protomerite : width deutomerite : : 1 : 1.5. Protomerite small, rounded at anterior end, one-third as high as wide. Septum concave up- ward, thus forming a protomerite in the shape of a double convex lens. No constriction at septum j perfectly smooth contour throughout, from 60 ILLINOIS BIOLOGICAL MONOGRAPHS [270 end to end. Deutomerite elongate cylindrical, broadest just below sep- tum where it attains one and a fourth times the maximum width of the protomerite. Slighly wider in anterior third than elsewhere, tapering slightly and terminating bluntly. Endocyte opaque in both protomerite and deutomerite. Nucleus undescribed, not visible in vivo. Cysts spheri- cal, 350 to 500;u, in diameter with thick epicyst. Dehiscence by rupture, spores fusiform, 12.5 by 7.5/i. Taken at Ealeigh, N. C. 'B.OBi Spiroholus sp. Habitat: Intestine ( ?). Crawley first described this species as Stenophora spiroboli, trans- ferring it later to the genus Cnemidospora when the cyst and spores had been examined, probably because of the character of the spore-integu- ment. The genus Cnemidospora Schn. (1882:446-7) is diagnosed thus: Protomerite subglobular, divided into two parts, the upper greenish gray, the lower yellow to brown; deutomerite elongate, cylindrical, spores ellipsoidal (nearly spherical) with a thick integument. No spore ducts in cyst.. The species in question does not coincide with the characters of the genus Cnemidospora. Neither the coloration of the protomerite nor the shape of the spores fits the generic description. Ellis has replaced the species in the originally assigned genus, where it undoubtedly belongs because of the form and coloration of the spo- ronts, the character of the cyst dehiscence, and the shape of the spores. STENOPHORA PONT ARIA (Crawley) Watson [Figures 11 and 12] 1903 Amphoroides fontariae 1913 Amphoroides fontariae 1916 Stenophora foniaria Stenophora: Sporonts solitary, ovoidal. Maximum length 135/i; width not given. Ratio length protomerite : total length :: 1 :4 to 1 : 5.5 ; width protomerite : width deutomerite : : 1 : 1.5 to 1 : 2. Pro- tomerite subglobose, widest in posterior two thirds, tapering to a blunt cone. Deep constriction at septum. Deutomerite elongate ovoidal, ter- minating bluntly. Endocyte nearly transparent in protomerite, very opaque in deutomerite. Nucleus not always visible in vivo, small, spheri- cal, with one karyosome. Cyst and spores unknown. Taken at Wyncote, Pa., Raleigh, N. C, and at East Falls Church, Va. Hosts: Polydesmus s^. &ixA Fontaria s^. Habitat: Intestine. Leger (1892) created the genus Amphorella, afterwards renamed Amphoroides by Labbe (1899 :20), to include species with solitary ovoidal sporonts having a protomerite short, compressed and crateriform, and Crawley 1913 :53 Ellis 1913b :274 "Watson (This paper) 271] STUDIES ON GREG ARINES— WATSON 61 spores rhombus-shaped (seen in one plane) and biconical, with but one integument. Leger and Duboscq (1904:375) compared one of their new species with the species in question. Their remarks are : "Stenophora chordeume nous parait, par sa forme, une espece tres voisine de la Gregarine des Polydesmus et Fontaria des Etats-Unis, signalee par Crawley (1903) sous le nom d' Amphoroides fontariae. Les figures qu'en donne cet auteur dans sa PI. I fig. 12, 13, 14 nous portent a croire, d'apres les caracteres de I'epi- merite, qu'il s'agit plutot d'un Stenophora que d'un Amphoroides. II est d'ailleurs impossible de se prononcer avec certitude sur ce point, car Crawley ne nous fait pas connaitre les sporocystes de sa Gregarine, et on sait que, outre la forme de I'epimerite, celle des sporocystes distingue nettement les Amphoroides des Steno- phora ; dans Amphoroides, ils sont biconiques ; chez Stenophora, ils sont ovoides." Thus the basis for the original inclusion of the species in the genus Amphoroides is not that of spore characteristics and until the spores are known the generic position of the species will not be absolute. The shape of the protomerite of the species under consideration is, however, very unlike that of the type species of this genus, A. polydesmi Leger, and hence the species cannot consistently be left in this genus. Its logical position seems to be with the Stenophoridae because of elimination from any other genus rather than from any positive character, and I should designate it Stenophora fontaria (Crawley). STENOPHORA BROLEMANNI Leger and Duboscq [Figure 13] 1903 Stenophora hrolemanni Leger and Duboscq 1903a :339-40 Stenophora : This gregarine is small, from 40 to 54/i, long and is com- pressed laterally, especially in the anterior part. It lives within the cell of the host during the greater part of its life cycle. The older intercellu- lar individuals are subspherical and occupy a cavity larger than that oc- cupied by the younger ones, which is formed by the greater destruction and compression of surrounding cells. The protomerite is invagiaated into the anterior end of the deutomerite like a cork into the neck of a bot- tle. "When the animal leaves the epithelium, the protomerite still retains its invaginated position. The protomerite in profile is cylindrical, rather flattened at the top, and when seen from the front it is as broad as high, widest anterior to the middle and possesses at the summit a small plate slightly concave upward and bearing in the center a small spherical pa- pilla. Leger and Duboscq say this papilla may correspond to a protrac- tile epimerite, for fibrillae seem to radiate from the apex outward over the anterior third of the protomerite. The deutomerite seen in profile is much larger at its posterior end than elsewhere, i. e., the animal is com- 62 ILLINOIS BIOLOGICAL MONOGRAPHS [272 pressed chiefly in the anterior half. A front view shows a deutomerite as broad as it is high. The nucleus is large, spherical or slightly ovoidal and contains one large karyosome. The parasite is characterized then by its compression, the invagination of its protomerite and by its inter- or intra-cellular location (the authors are not sure which). Taken in Provence, France, and on the island of Corsica. Hosts: Blaniulus hirsutus Brol., Brachyiulus superus Latzel, Brachyiulus pusU lus lusitanus Verh. Habitat : Intestine. STENOPHOKA NEMATOIDES Leger and Duboscq [Figures 14 and 15] 1903 Stenophora nematoides Leger and Duboscq 1903a :335-7 Stenophora: Sporonts solitary, elongate. Average length ITO/u,, maximum length 300/^. "Width not given. Eatio length protomerite : total length : : 1 : 10 ; width protomerite : width deutomerite : : 1 : 3. Protomerite cylindrical, slighly dilated a little anterior to septiun. Twice as long as wide, dome shaped at apex ; constriction at septum. Deu- tomerite normally with constriction at end of anterior third, or half; above this point considerably dilated, especially in posterior portion. Posterior half or two thirds of deutomerite, i. e., part below constriction, -cylindrical, ending in a broadly rounded or somewhat truncate extremity. The largest sporonts without the peculiar dilated portion of the deutome- rite; nematoid in shape, long, slender, cylindrical, often slightly curved and with a body as much as seventeen times as long as to protomerite (170 : 10), and not more than Tfj, wide throughout. Endocyte granules fine, homogeneous except in anterior end of protomerite where deeply staining chromatic granules are accumulated. Nucleus large and ovoidal, the long axis parallel to the long axis of the body. One large karyosome. Epimerite a large subglobular hyaline body. Cyst and spores unknown. Taken at Bastia, Corsica. Host: Strongylosomum italicum Latzel. Habitat : Intestine. The authors' conclusion concerning this species is as follows: "Bien que nous ne connaissions pas revolution complete de cette Gregarine, nous avons la conviction qu'il s'agit d'une espece voisine du Stenophora iuli, car a part la forme generale nematoide qui est ici tres caracteristique de I'espece, toutes le autres particularities structurales (forme du protomerite, caractere du noyeau, presence de grains chromatoides accumules surtout dans le protomerite, etc.) se retrouvent aussi chez les autres especes du genre Stenophora, lequel d'ailleurs est special aux Diplopodes." 273] STUDIES ON GREG ARINES— WATSON 63 STENOPHORA VARIANS Leger and Duboscq [Figures 16 and 17] 1903 Stenophora varians Leger and Duboscq 1903a :337-9 Stenophora: Sporonts solitary, dimorphic, elongate and globular. The elongate forms cylindrical or slightly compressed, slightly attenuate at both extremities, attaining a maximum length of 250/*. "Width not stated. Ratio length protomerite : total length : : 1 : 6 to 1 : 7 ; ratio width protomerite : width deutomerite : : 1 : 1. Protomerite cylindro- conical, 1^^ times as long as wide, its summit depressed, with an appar- ent pore. Constriction at septum. Deutomerite just below septum a lit- tle narrower than protomerite a short distance above. Deutomerite ir- regularly cylindrical, slightly curved in adults, truncate or broadly rounded behind. Nucleus spherical with a large karyosome. Endocyte of protomerite consisting of large deeply staining bodies, of deutomerite large non-staining bodies with a few scattered chromatic bodies. The globular sporonts more rare than the elongate ones but coexist- ing with the latter. Maximum length 35 to 40/;i. Deutomerite large, globu- lar protomerite, cylindro-conical and shorter than in the elongate forms. A small papilla at anterior end. Protomerite shows same staining reac- tion as elongate forms and the nucleus is relatively larger, with a much larger karyosome. Taken at Ajaccio, Corsica. Host: Schizophyllum corsicum Brol. Habitat : Intestine. Relative to the dimorphism, the authors make these remarks : "Au sujet de interpretation de ces deux formes de Stenophora dans un meme hote, on peut emettre plusieurs hypotheses : On bien la forme globuleuse, on raison de sa petite taille represente un stade tres jeune de la Gregarine; ou elle represente une espece distincte de la forme allongee; ou bien enfin il s'agit d'un dimorphisme sexuel dans des individus d'une seule et meme espece. Nous nous rattachons d'autant plus volontiers a cette derniere hypothese que Ton ob- serve assez souvent de jeunes formes allongees de volume bien inferieur a celui des formes globuleuses." The great difference in maximum lengths recorded of the elongate (250/*) and the globular (40/t) forms of this species would hardly indi- cate that the latter is mature. The immature specimens of most species of gregarines are more or less globular, stain deeper, have a protomerite which changes but little in shape as maturity approaches, and possess nuclei much larger in proportion than the adults, and often of a differ- ent shape from that of the adults. I have often seen these globular indi- viduals as large or a little larger than other individuals which had al- 64 ILLINOIS BIOLOGICAL MONOGRAPHS [274 ready assumed their adult form, and have attributed the difference to a difference merely in the amount of nourishment they have received. T think if we are to assume that there is a sexual dimorphism, we must look for two individuals of somewhere nearly the same size rather than one six times the size of the other. While sexual dimorphism is a factor to be looked for among grega- rines, it has never been definitely proven for a single species. There may be a difference in sexes among the sporonts, but if so, this difference seems to be of a chemical nature or of such slight morphological signifi- cance as to have been generally overlooked; and it should be evident among all or most of the members of the same family rather than con- fined to a few species only. STENOPHOKA PRODUCTA Leger and Duboscq [Figure 18] 1903 Stenophora iuli Leger and Duboscq 1903a -.SIS 1904 Stenophora producta Leger and Duboscq 1904:375-7 Stenophora: Sporonts solitary, very elongate. Sporonts 1000/t long, width not given. Ratio length protomerite : total length :: 1 : 20 ; ratio width protermite : width deutomerite : : 1 : 21. Proto- merite globular, slightly flattened top and bottom, sometimes slightly in- vaginated at the deutomerite. At apex a small papilla with an apparent pore. Deutomerite very long, cylindrical, broadly rounded behind. En- doeyte of protomerite finely granular, staining deeper than the deuto- merite. The nucleus ellipsoidal, with one large karyosome. An inverted xiphoid cone rounded at the summit, projecting from the septum down- ward into the deutomerite and consisting of homogeneous protoplasm staining deeper than that of the deutomerite. Probably consisting of nutriment manufactured by the protomerite and filtered through the sep- tum, to be eventually diffused through the deutomerite. Epimerite a small knob. Cysts spherical, size not given. Spores ovoidal, 5/* long. Taken at Corte, Corsica. Host : Julus varius Fabricus (Parajulus variusFah.). Habitat: Intestine. The reason for the confusion of names mentioned above appears in the following quotation from Leger and Duboscq (1904:375) : "Nous avons deja signale la presence de cette Gregarine dans I'intestin de Pachyiulus varius Fab. de la Corse (1903) et nous I'avons tout d'abord confondue avec Stenophora iuli, ne I'ayant observee a cette epoque que sur le vivant. Depuis une etude plus appro fondie sur des preparations colorees nous a convaincu qu'il s'agit d'une especee morphologiquement differente de Stenophora iuli (Frantzius) 275] STUDIES ON GREGARINES— WATSON 65 Schneider et nous la distinguerons de cette derniere sous le nom de Stenophora producta n. sp. . . . Nous n'avons pas remarque de ligne equatoriale £l la sur- face des sporocystes de Stenophora producta, ce qui distingue encore cette espece de Stenophora iuli." STENOPHORA ACULBATA Leger and Duboscq [Figures 19 and 20] 1904 Stenophora aculeata Leger and Duboscq 1904 :368-70 Stenophora: Sporonts solitary, elongate. Maximum length 60/*; width not given. Eatio length protomerite : total length :: 1 : 4 (approx.) ; width protomerite : width deutomerite : : 1 : 15. Proto- merite subglobular, a short cylindrical portion at the base, somewhat di- lated in middle, terminating in a small delicate elongate papiUa 1 to 2/* long. A conspicuous constriction at septum. Deutomerite cylindrical, broadly rounded behind. The endocyte of the deutomerite with proto- plasmic granules smaller than those of protomerite and less deeply stain- ing. Nucleus very large, subspherical in diameter, two thirds to seven eights the width of deutomerite, with a large karyosome. Cysts and spores unknown. Taken in Dauphine, France. Host : Craspedosoma rawlinsii simile Yej^la.. Habitat : Intestine. STENOPHORA POLYXENI Leger and Duboscq [Figure 21] 1900 Stenophora polyxeni Leger and Duboscq 1900 :1566-8 1903 Stenophora polyxeni Leger and Duboscq 1903 :xciu 1904 Stenophora polyxeni Leger and Duboscq 1904:370-1 Stenophora : Sporonts solitary, obese. Average length SO/i. "Width not given. Ratio length protomerite : total length : : 1 : 10 ; ratio width protomerite : width deutomerite :: 1 : 2 (approx). Protomerite very small, hemispherical or somewhat flattened. No apparent pore in anterior end, as in many Stenophoridae. Protomerite twice as wide as high. Widest at or just above base. Slight constriction at septum. Deu- tomerite elongate ovoidal in young and sac-shaped in older sporonts. En- docyte fairly homogeneous. Nucleus spherical, half the width of deuto- meritet, with a large karyosome. Cyst and spores not known. Taken at Grenoble, France. Host: Polyxenus lagurus (Linn.) Latreille. Habitat : Intestine. 66 ILLINOIS BIOLOGICAL MONOGRAPHS [276 STENOPHOEA SILBNE Leger and Duboscq [Figures 22 and 23] 1904 Stenophora silene Leger and Duboscq 1904:371-2 Stenophora: Sporonts solitary, dimorphic, an elongate and a glo- bular form. The elongate form 100/* in maximum length, width not given. Eatio length protomerite : total length : : : 1 : 10 ; width proto- merite : width deutomerite : : 1 : 1. Protomerite cylindrical, slightly dilated top and bottom, nearly flattened at top, an apparent pore at apex. Constriction at septum. Deutomerite cylindrical, gradually tapering toward posterior end. Endocyte of protomerite with large achromatic bodies, of deutomerite very finely granular and deeply staining. Nu- cleus large, half the maximum width of deutomerite, ovoidal, its longi- tudinal axis parallel to that of body, containing one large karyosome. The globose form, 55 to 60/* in maximum length. "Width not given. Eatio length protomerite : total length : : 1 : 6 ; width protomerite : width deutomerite : : 1 : 2.3. Protomerite similar to that of elongate form, but containing finely granular endoplasm as deeply staining as that of deutomerite. Deutomerite broadly ovoidal, widest below center. Nucleus less ellipsoidal than in elongate form. Cyst and sports not known. Taken in Dauphine, France. Host: Lysiopetalum foetidissimum Savi. Habitat : Intestine. "Howard Crawley (1903) a signale dans Lysiopetalum lactarium des Etas- Unis deux especes de Gregarines : I'une qu'il nomme Gregarina calverti dont la forme generale et la taille sent si differentes de celles de la precedente que Ton ne peut etablir de confusion; I'autre espece est rapportee au Stenophora iuK. II est possible que celle-ci soit identique a notre Stenophora silene, mais on ne peut I'aiBrmer, car Crawley ne donne pas de dimensions de son Stenophora." Stenophora silene is not the species described by Crawley (1903:51; 1903a :634-5) as Stenophora juU. Crawley's species attains a length of 400/t, S. silene of only 100/*. The protomerite of S. juli is broadly conical, 1.4 times as wide as high; of S. silene cylindrical, flattened at the apical end. Crawley's Gregarina calverti is still another species, now called Amphoroides calverti. Whether or not there is an actual dimorphism in the Stenophoridae is a problem still far from settled. The finding of elongate and globose forms in the same species and the difference in staining reactions can, I think, hardly be considered sexual dimorphism unless the two spo- ronts are of somewhere nearly the same size. In S. silene, the difference in length of the two is 100%. The difference in lengths of the elongate 277] STUDIES ON GREGARINES —WATSON 67 and globular sporonts is not to be accounted for by a mere shortening of the body, for the staining reaction and shape of the nucleus differ as well. The nucleus of the globular form is less ellipsoidal than that of the elongate form. In all Stenophoridae I have observed, the young trophozoites and younger sporonts have not yet attained that elongation of the nucleus which is characteristic of the adults, and a gradual transition can be observed in the same series of sections from a spherical to sub-spherical and finally to the elongate ellipsoidal nucleus of the adult. In all the gregarines I have studied, the young globular tropho- zoites contain less protoplasm and stain more readily and deeper than the adults. If globular and elongate specimens of approximately the same length can be procured or, at least, with protomerites of the same approximate size, and a young cyst shown to contain two individuals with different staining rections and differently shaped nuclei, then there is sexual dimorphism among the Stenophoridae. This has not yet been reported and there is too great a discrepancy in size of the elongate and globose forms to warrant calling them sexually unlike and the phenomenon sexual dimorphism. STENOPHORA CHORDEUME Leger and Duboseq [Figures 24 and 25] 1904 Stenophora chordeume Leger and Duboseq 1904:372-5 Stenophora: Two forms described for the sporonts. Elongate form 140/* long, width not given. Ratio length protomerite : total length :: 1 : 7.5; width protomerite : width deutomerite :: 1 : 2. Protomerite nearly twice as wide as high, widest along central portion, flattened above, with papilla and an apparent pore at apex. Conspicuous constriction at septum. Deutomerite an elongated irregularly shaped sac widest below the middle and tapering rapidly to a point. Endocyte of protomerite clear, containing large non-staining granules. Endocyte of deutomerite homogeneous with a few scattered irregularly shaped chromatic granules. Nucleus spherical, with a large karyosome. Globular form with maximum length of 100/*. Width not given. Ratio length protomerite : total length :: 1 : 5; width protomerite : width deutomerite : : 1 : 2.5. Protomerite same shape as in elongate form except that the constriction at septum is deeper and the proto- merite sometimes partially invaginated into anterior end of d^utomerite. Latter ellipsoidal and nearly spherical. Endocyte of protomerite deeply staining, like that of deutomerite. Latter with long scattered chromatic 68 ILLINOIS BIOLOGICAL MONOGRAPHS [278 filaments. Nucleus spherical, with, a large karyosome and numerous irregular chromatic granules. Cyst and spores unknown. Taken at Grenoble, France. Host: Ghordeuma silvestre C. Koch (C. sylvestre C. K.). Habitat: Intestine. Concerning the long chromatic filaments in the deutomerite, the authors say (1904:374): "Sur la signification de ces singulieres formations, on ne peut qu'emettre des hypotheses : ou bien ce sont des productions parasitaires, ce qui nous parait pen probable, car toutes les formes globueuses en montrent a I'exclusion des formes allongees, ou bien ce sont des produits derives de I'activitie cellulaire. Tout en nous rattachant plus volontiers a cette maniere de voir, nous ne saurions dire si ces produits prennent naissance dans le cytoplasme comme substances de reserve ou de dechet comparables aux cristalloides deja signales chez certaines Gregarines, ou bien s'ils derivent de la chromatine nucleare. Dans tout les cas, nous ne croyons pas devoir les considerer comme des elements chromatiques ou chromatides, destines a jouer un role important dans les phenomenes sexuels et nous les regardons plutot comme des produits ergastoplasmiques." As heretofore, the size of the two dimorphants is considerable (50%). The deutomerite of the smaller contains many long chromatic filaments. At the same time, the deutomerite of the elongate form is not devoid of scattered chromatin, which may be the broken remnants of threads in a younger stage. Only two diplopods were parasitised, one harbored many parasites; the other on the contrary very few. It is possible, from the limited material at hand, that still longer and more mature elongate forms may exist and bring up the percentage still higher. For the views of the authors concerning its relationships compare the paragraph quoted under Stenophora fowtaria (page 60). From the data given, then, it is impossible to state with certitude that the species are or are not the same. Dimensions correspond closely. I have not included Crawley's species here because of difference in shape of the sporonts but have left it as a distinct species and placed it among the Stenophoridae, the name now being Stenophora fontaria (Craw- ley). STENOPHORA CORSICA Leger and Duboscq 1903 Stenophora Corsica Leger and Duboscq 1903a :314 No description or figure is given for this species. It is merely mentioned as a parasite found in Craspedosoma legeri Brol. at Vizza- nova, on the island of Corsica. 279] STUDIES ON GREGARINES— WATSON 69 STBNOPHOEA EOBUSTA Ellis [Figure 26] 1912 Stenophora rdbusta EUis 1912a -.8-10 Stenophora: Sporonts solitary, relatively short and thick. Average length 153/x ; minimum length 140/i ; maximum 180/*. Width 67/*, as aver- age. Ratio length protomerite : total length : : 1 : 8 ; with protome- rite : width deutomerite : : 1 : 2.5. Protomerite small, dome-shaped or conical. Slight concavity in apical portion, widest at junction with deutomerite. No constriction at septum. Deutomerite broadly ellipsoi- dal, widest in center, slightly rounded behind. Bndoeyte fairly clear in all parts but especially so in protomerite. Nucleus spherical, faintly visi- ble or obscured in vivo. One or more karyosomes. Cyst and spores not known. Taken at Boulder, Colo. Hosts : Parajuhis venustus Wood ; Ortho- morpha gracilis (Koch) ; Orthomorpha sp. Habitat: Intestine. STENOPHORA COCKERELLAE Ellis [Figure 27] 1912 Stenophora cockerellae Ellis 1912 :681-5 Stenophora: Sporonts solitary, elongate. Average length 500 to 800/t. Minimum length 186/t; maximum 850/*. Width deutomerite not given. Ratio length protomerite : : : :1 : 14.5 to 1 : 17 in adults ; width protomerite : width deutomerite : : 1 : 2. Protomerite more or less globose, widest in posterior half. Slightly constricted at septum. Peculiar in that the protomerite protrudes and retracts a short rounded papilla. Deutomerite widest in anterior sixth. Posterior end broadly rpunded to square. Endocyte of protomerite pale gray, rather opaque, nearly filling protomerite. Endocyte of deutomerite dense, lead gray to almost black. Nucleus spherical, diameter two thirds the width of deu- tomerite. Not visible in vivo. Cyst and spores unknown. Taken at Quirigua, Guatemala. Host: Orthomorpha coarctata Intestine. 70 ILLINOIS BIOLOGICAL MONOGRAPHS [280 STENOPHORA ELONGATA EUis [Figure 28] 1912 Stenophora elongata Ellis 1912 :685-6 Stenopliora : Sporonts solitary, very elongate. Length 200 to 300;* (average). Minimum length 21;ii; minimum 390/*. "Width of deutome- rite not given. Length of protomerite : total length : : 1 : 18 to 1 : 26 ; width protomerite : width deutomerite :: 1 : 1:6. Protomerite more or less pentagonal (seen from side), truncate, wider than long. Con- striction at septum distinct. Deutomerite widest in anterior third, pos- terior end rounded. Bndocyte of protomerite dense, opaque, dark gray ; of deutomerite gray, very dense. Nucleus not visible in vivo, spherical, one half to seven eighths width of deutomerite. Cyst and spores un- known. Taken at Quirigua, Guatemala. Host: Orthomorpha coarctata (Saussure). Habitat: Intestine. STENOPHORA IMPRESSA Watson [Figure 53] 1915 Stenophora impressa "Watson 1915 :29 This parasite was found to be very common in the intestine of Paraju- lus impressus (Say), one of the common small diplopods found at Ur- bana, Illinois. The sporonts are isolated, none being associative. They are elon- gate ellipsoidal in shape, widest through the central portion of the deu- tomerite or at the beginning of the posterior two thirds. The protomerite is conical, dilated just above the base and tapering rather acutely but with a blunt point at the apex. The widest part is some little distance anterior to the septum, the constriction at the septum being conspicuous but not deep. The length of the protomerite is about one tenth of the total length of the sporont. The deutomerite broadens gradually from the septum to the central region and then as gradually becomes nar- rower, ending in a very blunt extremity of much the same general shape as the anterior end of the protemerite. At its widest part, the deuto- merite is about twice the greatest width of the protomerite. The endocyte is gray with no trace of tan. The protomerite con- tains a few large granules of more or less transparent protoplasm and the deutomerite content is finely granular, homogenous, and often so dense as to appear black in transmitted light. The epieyte is thin, trans- parent, of even width throughout, and is longitudinally striated. At the anterior end of the protomerite there is an invagination of the epi- 281] STUDIES ON GREGARINES— WATSON 71 cyte. The latter is here very thin and readily breaks, with a consequent extrusion of the endocyte. The nucleus is spherical, generally visible in the adults and contains one large karyosome which is visible without staining. The trophozoite of Stenophora impressa was studied in sections made of the intestine of the parasitised Parajuli. The young parasites lie imbedded between the cells of the intestinal epithelium, having made a place for themselves by the absorption and destruction of the cell originally entered, and by the absorption, destruction, and pushing aside of contiguous cells; they lie with the apex of the protomerite next the mesothelial wall. As is often the case with the Stenophoridae, there is never developed an epimerite. Since the whole parasite lies embedded, there is abundant surface through which osmosis may take place without the additional presence of an epimerite. The protomerite of trophozoites is often deeply embedded in the deutomerite, like a cork in the neck of a bottle. Two types of movement were observed. A rapid gliding over the surface at the rate of 6/t per second was very common. This form of movement persists for an hour or more after the animals are placed on the slide. Partial rotation of the body on its own axis and a bending of the body to an angle of about 45° were frequent. The epicyte in the re- gion just below the septum is very flexible, resulting in a nodding of the protomerite from side to side. The extension of the upper part of the deutomerite which causes the protomerite to drop is effected slowly, but withdrawal of protoplasm is done by a sudden jerking movement which restores the normal shape. Cysts 160/i in diameter were found, but none could be induced to develop to completion in a water medium. This species differs from Stenophora lactaria in a) general shape of the deutomerite, b) shape of the posterior end of the body, and c) shape of the nucleus. A table of the various dimensions given in microns follows : Total length of body. 155 Length of protomerite 20 Length of deutomerite 135 Width of protomerite 30 "Width of deutomerite. _ _ 70 Batio length protom. : total length........! :7.5 1:9 1:10 1:10 1:11 1:11 width protom. : width deutom. 1 :2.3 1 :2 1 :2 1 :2.3 1 :2.4 1 :2.1 270 240 270 390 345 30 25 25 35 30 240 215 245 355 315 35 35 30 48 48 70 70 70 115 100 72 ILLINOIS BIOLOGICAL MONOGRAPHS [282 STENOPHOEA LACTARIA Watson [Figure 55] 1915 Stenophora laciaria Watson 1915 :29-30 A gregarine which was found with relative frequency is this one from the intestinal tract of the small diplopod Callipus lactarius (Say), taken at Urbana, Illinois, during the month of October, 1914. The infec- tion per host was heavy and sections of the alimentary tract showed the latter half of the same to be heavily parasitised. A table of various dimensions of the parasites at different ages fol- lows. There is considerable discrepancy in the ratios given but the fact that there is a gradual transition from one extreme to the other indi- cates that a single species is involved. Measurements were made only of individuals which to all appearances were equally expanded; dimen- sions are all given in microns : Total length sporont 175 216 Length protomerite 28 27 Length deutomerite 145 189 Width protomerite 30 30 Width deutomerite 54 53 Ratio length protom. : tl. length.! :6 1 -.7.5 width prot. : width deutl :1.8 1 :1.8 The sporonts, as in all members of this family, are solitary until just previous to cyst formation. The body, when moderately expanded, is shaped like a classic vase, widest near the top and tapering very grad- ually. The protomerite is small in comparison with the deutomerite, be- ing from one eighth (in young specimens) to one sixteenth the total length. It is conical, widest just anterior to the base, and its breadth ex- ceeds its height. (39 by 30/t; 32 by 29/1,). It is from 0.4 to 0.6 as wide as the deutomerite at its widest part. There is a slight invagination at the anterior end. The deutomerite is widest a short distance below the conscription at the septum and tapers gradually toward the posterior end, terminating in a blunt cone. The protomerite is quite or nearly transparent, containing but few large crystal granules of protoplasm which stain deeply. There is an ap- parent pore at the anterior end. The deutomerite is more or less dense and opaque, being pearly white in reflected light and light or dark gray, depending on the amount of protoplasm present, in transmitted light. The density depends on age, the young trophozoites containing a few pale gray granules, the oldest and largest sporonts being filled with pro- 293 304 339 455 480 30 30 20 36 30 213 264 319 419 450 39 29 39 35 39 90 61 90 65 90 1:10 1:10 1:17 1:13 1:16 1:2.3 1:2.1 1:2.3 1:1.9 1:2.3 283] STUDIES ON GREGARINES— WATSON 73 toplasm which gives to them a blackish appearance. The deutomerite stains a fairly homogeneous shade, and the small granules here do not absorb as much of the stain as do the larger protoplasmic granules. The epicyte is colorless and very thin, even at the septum. Longitu- dinal striations are discernible. This epicyte is much more resistant than in many gregarines studied, for animals remain alive on the slide in a water medium or in normal saline for maxiy hours, and when they finally become immotile, retain their shape. After several days on the slide, they have been noted to be intact with the body only a little more nearly globular from osmosis than in the normal parasites. This may be due to the thinness of the epicyte and its great permeability. Myone- mes were seen in stained sectioned specimens as deeper staining dots, larger than the deutomerite granules and lying along the periphery of the endocyte in the longitudinal striations. The nucleus of sporonts is an elongate ellipsoid, generally placed diagonally and reaching almost entirely across that part of the deutome- rite in which it lies. In large specimens, it approximates 55 x 30/*. It contains one large spherical or slightly ovoidal karyosome which stains evenly and lightly throughout with Bhrlich's hematoxylin. The nu- cleus is not visible in vivo in the large and dense individuals. In young specimens, it is spherical, becoming ellipsoidal as the sppront stage ap- proaches. The trophozoite is much less dense than the sporont. The epimerite is a round, sessile, transparent knob. The sporozoite is a deeply staining, spindle shaped body which pene- trates the cell at is free end, becomes embedded, grows, and absorbs the host cell which it entered. The whole trophozoite, not merely the epime- rite, lies embedded and after it has destroyed the originally entered cell distorts and compresses those adjoining. It remains embedded until it has practically outgrown the cells of the epithelium and easily escapes into the lumen through the canal it has formed by cell destruction. The trophozoite is able to move about while embedded. In cross sections of the intestine the parasite, still embedded, is sometimes cut crosswise, in- dicating that it lies with its longitudinal axis parallel to that of the host, and in one instajice it lay with the protomerite pointed toward the lumen rather than toward the mesothelial wall, the normal position. The gliding movement common to most Polycystids is functional here and the animal moves forward very rapidly in a straight line, often with a constant turning of the protomerite from side to side which af- fects neither the rapidity nor the direction of motion. Progression has been observed at the rates of 6.5ju, and 7.5/* per second. Bach of these rates is for a different specimen and each movement extends at a uniform rate over several minutes. No gelatinous stalk was seen trailing the ani- 74 ILLINOIS BIOLOGICAL MONOGRAPHS [284 mal either with or without the use of a stain on the slide. Ameboid move- ment was noted, chiefly confined to the anterior part of the deutomerite ; it results in the nodding of the 'head' as many as thirty times without ceasing or decreasing speed. The protomerite does not change in shape or size, neither does the posterior two thirds of the deutomerite. The epicyte of the shoulder region stretches on one side, the endocyte flows into the pocket thus formed, and the inactive protomerite, its equilibrium disturbed, drops to one side and then to the other as the pockets form now on one side and now on the other. Structures which cause move- ment must therefore be much more numerous or else much more active physiologically in this restricted area than elsewhere. Cysts are spherical and vary from 150 to 270/* in diameter. I have as yet been unable to procure development of the cysts. A number were kept from two days to two weeks in water and normal saline media and when opened revealed no indication of having undergone progression beyond the dissolution of the walls separating the two conjugants. Staining revealed no differentiation whatever in the apparently homo- geneous protoplasm. This species is distinguished from Stenophora larvata (Leidy) EUis by the considerable difference in size. Leidy 's species varies from 100/* to 800/A in length, while 8. lactaria does not exceed 480/t. His form varies in width from 30/i to 20fi, the other never exceeding 90/x. The ratio of length protomerite : total length in S. larvata (largest individual) is 1 : 26 ; in S'. lactaria it never exceeds 1 : 16. The nucleus in the for- mer is spherical and about 70/* in diameter; in the latter it is ellipsoi- dal and smaller, 55 by 30/* in the largest measured! The host is a differ- ent diplopod found, however, in the same habitat. S. lactaria differs from 8. elongata Ellis and from 8. cockerellae Ellis in size, shape of the protomerite and deutomerite, and in shape espe- cially of the posterior end of the deutomerite. STENOPHORA DIPLOCORPA Watson [Figure 54] 1915 Stenophora diplocorpa "Watson 1915 :29 A number of most peculiar polycystid gregarines were found in the common small diplopod, Euryurus erythropygus (Brandt), at Ur- bana, Illinois. The parasites were abundant in each of the two speci- mens examined, each host containing more than a dozen gregarines. The sporonts are solitary. The shape is more or less cylindrical, the body being very much attenuated. The protomerite is as wide as it is long and is from one-sixteenth to one-twenty-fifth the total length of the 285] STUDIES ON GREGARINES— WATSON 75 body, and there is no indentation at its anterior end as in many of the Stenophoridae. The anterior half of the protomerite is rather broadly conical and is blunt at the apex. There is but a slight constriction at the septum in extended individuals. The anterior end of the deutome- rite is but little wider than the protomerite just in front of the septum. The deutomerite gradualy Tvidens, becoming twice the maximum width of the protomerite. It is incompletely separated into two nearly equal parts by a deep constriction at about the middle and behind this con- striction the body is cylindrical, of practically the same width through- out, terminating in a blunt, well rounded cone. The protomerite is transparent or nearly so, containing a few large irregular deeply staining granules clustered near the septum. The deu- tomerite is plaia tan in color and contains smaller homogeneous gran- ules densest just anterior to the constriction in the walls, least dense at the posterior end, and otherwise fairly evenly distributed. The endo- plasm is much less opaque than in many gregarines. The epicyte is thick, transparent and of even width throughout except at the constric- tion in the middle of the deutomerite where it becomes considerably thicker. Longitudinal striations are easily discernible in the epicyte. The myonemes are well developed, especially at the constriction and in the region of the septum, and are indicated by a series of delicate some- what reticular fibrillae embedded in the peripheral layer of the endo- cyte and running crosswise of the body. The nucleus is visible in vivoj it is spherical and in diameter two thirds the width of the body just back of the deutomerite constriction. It lies just posterior to this con- striction. One large karyosome is visible within. The epimerite evidently persists after its usefulness is over, and was seen in one instance on a fairly large specimen free in the lumen of the intestine. It is a large hyaline smooth knob with a short stalk broad at the base. Neither sporozite nor cyst was seen. The parasite is fairly active. Gliding motion, accompanied by no bodily contortion was observed at rates of 11 and 7/t per second. Bach rate was fairly constant for the given gregarine for a period extending over several minutes. A contortion of the body is common, either with no displacement of the body as a whole or in connection with the glid- ing motion. In fact, it was difficult to find an animal in simple progres- sion which was not at the same time performing some sort of contor- tion. The region of the septum is very motile. Here the epicyte ex- pands and contracts, with an inflow or withdrawal of the endocyte, just as in the case of an amoeba. Tiny processes can be seen extruded sev- eral at a time or a large portion of the endoplasm of the region may be pushed out one at a time. In the latter case, the heavy and rigid proto- 1^ ILLINOIS BIOLOGICAL MONOGRAPHS [286 merite is overbalanced and drops to one side. Immediately thereupon an OTitpushing of protoplasm on the other side either restores the nor- mal condition or causes a nodding to the opposite side. This movement may continue with surprising rapidity and extend over a long period of time. The deutomerite above its median constriction is very motUe, but the portion below is never involved in violent contortions. This species is similar in general outline to Stenophora nematoides L6ger and Duboscq (1903a :335-7). Both have the peculiar and hitherto unique constriction at the middle of the deutomerite. They differ in the shape of the protomerite, which in Leger and Duboscq 's species is much longer than wide ; in the shape of the nucleus, which in S. nema- toides is elongate ovoidal and in ;Si. diplocorpa is spherical; and in the character of movement. I have in no case observed the nematoid shape which is assumed by 8. nematoides and is due to the elongation of the body and the entire disappearance of the constriction. Motion in S. dip- locorpa is confined chiefly to regions above the constriction and the lat- ter never entirely disappears. A table of measurements follows, in which all dimensions are given in microns : Total length of body 9,97 325 262 335 359 . 19 20 12 15 14 .278 305 250 320 345 . 20 20 20 15 15 . 45 57 40 45 45 Length of protomerite Length of deutomerite Width of protomerite.. Width of deutomerite Ratio length protom.: total length 1:16 1:16 1:22 1:22 1:25 width protom.: width deutomerite. 1:2.2 1:2.8 1:2 1:3 1:3 Diameter nucleus - 20 22 18 22 24 CNBMIDOSPORA LUTEA Schneider [Figures 56 and 57] 1882 Cnemidospora lutea Schneider 1882 :446-8 Cnemidospora : Sporonts solitary, elongate. Total length 500/*. Width not given. Ratio length protomerite : total length :: 1 : 15; width protomerite : width deutomerite :: 1 : 1.6. Protomerite sub- globular, broader than long, in the ratio of 4 : 3. Divided into two parts, the anterior the shape of a double convex lens, without the charac- teristic endocyte granules, and tinted greenish ; the posterior, larger, por- tion containing yellow or brown endoplasmic granules. Deep constriction 287] STUDIES ON GREGARINES— WATSON 77 at septum. Deutomerite cylindrical, tapering very slightly and ending ia a broad flattened extremity. Endoeyte of deutomerite brown, rather dense. Nucleus ellipsoidal, twice as long as wide, containing one or more karyosomes. Myocyte apparent. Cysts not described. Spores ellipsoi- dal, with a thick integument. Taken at Poitiers, France. Host : Glomeris sp. Habitat : Intestine. There is but one species in this genus. Crawley (1903a :638-9) de- scribed a species as Cnemidospora spiroboli but it has been removed to the genus Stenophora, because it has none of the characters of the pres- ent genus. AMPHOEOIDES POLYDBSMI (Leger) Labbe [Figure 58] 1892 Amphorella polydesmi Leger 1892 :132-4 1899 Amphoroides polydesmi Labbe 1899 :20 1903 Amphoroides polydesmi Leger and Duboscq 1903a :314 Amphoroides: Sporonts solitary, ovoidal, rather short and broad. Length 170 - 200/i. Width not given. Ratio length protomerite : total length : : 1 : 20 ; width protomerite : width deutomerite : : 1 : 26. Pro- tomerite very short, depressed and cup-shaped within. Three times as broad as h^h. Widest at top, where it is wider than the deutomerite just below septum. A constriction at septum. Septum pushed up in the middle to form a dome which is higher at its summit than the proto- merite itself, the latter appearing as a crenulate collar about it. The deutomerite is cylindrical through the anterior third, widening appre- ciably to form a shoulder, below which it gradually tapers, ending in a broad flattened extremity of approximately the same width as the ante- rior third of the deutomerite. The endoeyte is yellow-brown, the nu- cleus spherical, its diameter as great as the width of the base of the deu- tomerite and contains one large karyosome. The epimerite is a cylindro- conical or globular papilla. Cysts are spherical, 150/t in average di- ameter, dehisce by simple rupture and the spores are biconical, 7.8 by 3.8/t. Taken in the valleys of the Vienne and the Loire, France, and at Vizzanova and Corte, Corsica. Hosts: Polydesmus complanatus (L.) ; Polydesmus dispar Silvestri. Habitat: Intestine. This species was first described by Leger as Amphorella polydesmi. The generic name was preoccupied and Labbe changed the name to Am- phoroides. At the same time Labbe included with A. polydesmi as a synonym Oregarina polydesmivirginiensis of Leidy, probably because of the identity of the generic name of the hosts. The character of the 78 ' ILLINOIS BIOLOGICAL MONOGRAPHS [288 protomerites alone would radically differentiate the two species. The latter has since been named Stenophora polydesmi. Labbe says of the Antiaocephalidae, to which the genus Amphoroi- des belongs the members are parasites of the "tube digestif d'Arthropodes carnaissere" but the diplopod Polydesmus is surely not carnivorous. AMPHOROIDES CALVERTI (Crawley) Watson [Figure 52] 1903 Oregarina calverti Crawley 1903 :48 1903 Gregarina calverti Crawley 1903a :638 1915 Amphoroides calverti Watson 1915:30 Amphoroides : Sporonts solitary, elongate. Maximum length 1670/1, average length 1400/*, average width 120/i. Ratio length protomerite : total length : : 1 :47 ; width protomerite : width deutomerite : : 1 -.2.5 to 1 : 3. Potomerite greatly compressed in sporonts, shallow, five times as wide as high. Deep crater within the top. Constriction at septum sharp and deep. Deutomerite elongate, widest in anterior third, tapering to a sharp point. Endocyte of protomerite tan in color, not dense ; of deu- tomerite opaque, white. Nucleus small, spherical, not visible in vivo. Myocyte well developed. Cysts spherical, 380/t in average diameter. De- hiscence by simple rupture. Spores not known. Taken at Wyncote, Pa., and Urbana, 111. Host: Callipus lactarius (Say); Lysiopetalum lactarium (Say). Habitat: Intestine. This species was described by Crawley (1903) as belonging to the genus Gregarina. Later (1903a) he described the cysts and spores as follows : "Cysts spherical 250 - 360/1, in diameter. — Dehiscence effected by sporeducts, from 4 to 8 in number, not exceeding in length the diameter of the cyst. Spores doliform, 13 by Sfi. A single thick spore wall. — " 1 have seen one cyst from this species which measured 380j«, in di- ameter and indicated dehiscence by rupture and not by spore ducts. Crawley probably confused the cysts of this species with those of another which may have been developing in the damp chamber at the same time. This gregarine bears no resemblance to the members of the genus Gregarina whose cysts dehisce by spore ducts, either in its habitat, in a diplopod, or in any of the characteristics of the sporont. The elongate shape, character of movement by slow contortions, great size of the indi- vidual, and chiefly the fact that all the animals are solitary tend to prove conclusively that this species is not a member of the genus Gregarina. I 289] STUDIES ON GREGARINES— WATSON 79 think that when the unauthentic species have all been properly placed, it will ultimately be shown that members of the genus Gregarina are aM associative during the greater part of their adult sporont life. I plaee this species in the genus Amphoroides because of the shape of the pro- tomerite. Appendix to the Stenophoridae Two and only two species have been described as Stenophoridisie which are not parasites in diplopods. These are Stenophora erratica (Crawley) (1907:220-8) and /S. £^m6eZi Ellis (1913:462-5). The former was placed in this family on very slender evidence, viz. : At the anterior tip of the protomerite is a "low papilla within which are traces of a pore. It is this character which led me to place the gregarine in the genus Stenophora." The author notes later the following (1907:221) : "The suggestion is permissible that this form is actually the common Steno- phora Julipusilli Leidy, somewhat altered in appearance from being in the wrong host. Crickets and Julidae frequently occur in the same environment, and the former might readily swallow the spores derived from the feces of the latter. This done, the spores might readily develop, although producing slightly atypical gre- garines." The present writer has placed the species in a new genus and called it Leidy ana erratica (Crawley). For argument relative to this posi- tion, see under this species, among the Orthopteran parasites. Ellis (1913) described from a beetle a parasite he calls Stenophora ginibeli. "The epicyte of the apex of the protomerite is quite thin and the sarcocyte of this region is driven into a papilla which results from the expansion of the thin epicyte." Such a papilla has been found nowhere else among the Stenophoridae except in S. cockerellae. The present writer has often observed an ex- pansion of the epicyte at the apex of the protomerite after the animal has been on the slide for some time in a water medium and it is due to osmo- sis and the expansion of the epicyte at its weakest point. This gregarine has been removed from the genus Stenophora and placed in the genus Gregarina. The name now stands Actinocephalus gimbeli. With this disposition of the above two species, the family Stenophori- dae is foimd nowhere outside of the family Diplopoda and the diplopods are parasited almost but not exclusively by the Stenophoridae. It is in- teresting to note in this connection the fact that very rarely is the same species of gregarines found in more than one species of host. Each spe- cies of diplopod may be expected to yield its specific parasite, althougl this is not without exception. ILLINOIS BIOLOGICAL MONOGRAPHS [290 The species of parasites among the Stenophoridae do not appear to be as widely distributed, i. e. as cosmopolitan, as do those of other grega- rines, e. g. of the genus Gregarina, widely separted localities seemingly yielding different parasites from the same host or from closely allied hosts. It is true, however, that much less work has been done in differ- ent parts of the world on the diplopod parasites than on those of the beetles and Orthoptera. One is led to believe that each family of gregarines has its unique order or narrowly restricted orders of insects which it infects and that each genus of gregarine is confined to a single host or to very closely re- lated species. POLYCYSTID GEBGARINES IN THE CHILOPODA* Name of Parasite dactylophoridae Daciylophorus robustus Leger Nina gracilis Grebnecki Nina giardi (Leger) Sokolow Nina giardi corsicum (Leger and Duboscq) Sokolow Nina indicia Merton Echinomera hispida (Schneider) Labbe Echinomera horrida (Leger) Watson Acutispora macrocephala Crawley Trichorhynchus pulcher Schneider Rhopalonia geophili Leger Rhopalonia stella Leger ACTINOCEPHALIDAE Actinocephalus striatus Leger and Duboscq Actinocephalus dujardini Schneider Amphorocephalus amphorellus Ellis Hoplorhynchus actinotus (Leidy) Crawley Hoplorhynchus scolopendras Crawley SPECIES OF UNCERTAIN DETERMINATION Trichorhynchus lithobii Crawley Name of Host Cryptops hortensis Leach Cryptops anomalons lusitanus Verh. Scolopendra cingulata (Latr.) Scolopendra . oraniensis Scolopendra oraniensis lusitanica Verh. Scolopendra subspinipes Leach Lithobius forficatus Linn. Lithobius coloradensis Cock. Lithobius calcaratus Koch Lithobius forficatus Linn. Scutigera forceps (Raf.) Scutigera sp. Himantarium gabrielis Linn. Stigmatogaster gracilis Mein. Himantarium gabrielis Linn. Scolopendra cingulata Latr. Lithobius forficatus Linn. Scolopendra heros Giard Scolopocryptops sexspinosus (Say) Scolopendra woodi Meinert OTHER SPECTES UNNAMED *The parasites are arranged in chronological order under each genus. 291] STUDIES ON GREGARINES— WATSON 81 DACTYLOPHORUS ROBUSTUS Leger [Figure 29] 1887 Dactylophorus sp. Schneider 1887 :67 1889 Dactylophorus sp. Balbiani 1889:41 1892 Dactylophorus robusta Leger 1892:124-7 1899 Dactylophorus roiustus Labbe 1899:17 1903 Dactylophorus rohustus Leger and Duboscq 1903 :310-1 Dactylophorus: Sporonts solitary, elongate. Length 700-800/t. Width not given. Ratio length protomerite : total length : : 1 : 30. Width protomerite : width deutomerite : : 1 : l^. Protomerite at top ap- proximately twice as wide as deutomerite, broadest at top, six times as wide as high. Periphery of upper margin set with numerous small up- wardly directed digitiform processes which constitute the epimerite. Deu- tomerite elongate, re^larly cylindrical in anterior third then becoming much narrower and ending in a long acuminate point. Nucleus ovoidal, twice as long as wide, containing several karyosomes. Endocyte yellow. Cysts spherical, 200/i in diameter, dehiscence by pseudocyst, spores cylin- drical, rounded at ends, 11 by 4.3/t. Taken at Grenoble, France, and on the island of Corsica. Hosts Cryptops hortensis Leach; Cryptops anomalons lusitanus Verb. Habi- tat: Intestine. Labbe (1899:17) attributed the naming of the genus Dactylopho- rus to Balbiani. The latter, however, says : "C'est d'abord une Gregarine que je crois nouvelle, a moins qu'elle ne soit I'espece que M. A. Schneider dit avoir decouverte chez les Cryptops, et a laquelle il donne le nom de Dactylophorus . C'est sans doute la presence de cet ap- pendice qui a valu a notre espece le nom Dactylophorus, qui lui a ete donne par M. Schneider." Balbiani described a polycystid gregarine from the digestive tract of Cryptops sp. as follows : "La Gregarine a la forme d'iine massue etroite, etiree en une longue pointe asa partie posterieure. Sa longueur moyenne est de 0.41 mm. et sa larguer, prise dans la portion renflee du corps, de 0.035 tnm. Le segment anterieur ou protomerite est petit, connoide, et prolonge sur un de ses cotes, en un court appendice obtus dirige en avant." Labbe considered this species identical Avith that later described by Leger as D. rohustus, probably from the fact that the specimens were taken from the same chilopod (Cryptops). It is evident, however, from 82 ILLINOIS BIOLOGICAL MONOGRAPHS [292 fibres of the two species, that they are quite unlike. Balbiani's species lacks the dilated flattened protomerite with its digitiform processes, but has rather a high irregular cylindrical protomerite with an eccentric, conical, forwardly directed projection. Moreover, the deutomerite is quite different in shape from that of D. robustus (compare Figures 29 and 47) and the nucleus in the one species is spherical, in the other ovoi- dal. Balbiani's figure compares favorably with figures of sporonts of Echinomera hispida (Schneider) Labbe in the following respects; a) the eccentrically placed cone at the apex of the animal, b) the shape of the protomerite, c) the shape of nucleus. In the case of E. hispida, the epi- merite persists and the cone is a part thereof. Balbiani's figure shows no epimerite, neither does it indicate the digitiform processes characteristic of the other. For these reasons, I do not wish to regard the two species as identical, but rather to leave the one as indefinitely placed. Its origi- nal position is obviously incorrect; and the epimerite which is needed to correctly diagnose it not having been discovered, its correct systematic position cannot be determined. Figure 47 is copied from Balbiani's drawing. NINA GRACILIS Grebnecki [Figure 30] 1873 Nina gracilis Grebnecki 1873 : ? 1887 Pterocephalus noMlis Schneider 1887 :68-9 1909 Nina gracilis Leger and Duboseq 1909 :33-68 Nina : Sporonts solitary, very elongate. Length,4 to 5 mm. Width not given. Ratio length protomerite : total length :: 1:26; width protomerite : width deutomerite : : 1 : 0.1. Protomerite bilater- ally symmetrical, divided into two equal lobes by a perpendicular con- striction, these two lobes widely separated at one extremity to form an up- turned cornucopia. The free upper extremity of each lobe bordered with a longitudinal row of short sharp spines, from which project long thread-like filaments. Deutomerite constricted just below septum then dilated slightly, the lower half regularly cylindrical, and terminating in a short bluntly pointed extremity. Nucleus slightly ovoidal with sev- eral small karyosomes. Csyts spherical. Spores regularly ellipsoidal with one integument, united in chains diagonally. Taken at Poitiers and at Grenoble (?), France. Hosts: Scolopen- dra cingulata Latr. (8. cingulata var. hispanica Newp.). Habitat: Intestine. 293] STUDIES ON GREGARINES— WATSON 83 Labbe (1899:17) says KoUiker's (1849:35) Gregarina scolopendra, from Scolopendra morsitans Sieb. is probably the same gregarine as the above. But the protomerite is very different from that of the genus Nina and indicates at once Labbe 's error. KoUiker gives no description of the epimerite and it is impossible to say in what genus his specimen should be placed. His drawing is reproduced in my Figure 48. Leger and Duboscq recognize the species and fully discuss its cyst formation. NINA GIARDI (Leger) Sokolow 1899 Pterocephalus Giardi Leger 1899 :390-3 1900 Nina giardi Sokolow 1911 :281 Nina : Sporonts solitary, elongate. Length 4 mm. "Width not given. Protomerite very broad at the upper extremity, bilaterally symmetrical, consisting of two long parallel horizontal lobes separated at one extrem- ity and upturned at the other, with a small vesicular body near this end. Each lobe set with a row of short upwardly directed teeth from which project long slender sinuous filaments. Deutomerite long, slender, cylin- drical, tapering slightly at the posterior extremity and ending bluntly. Cysts spherical. Spores with two envelopes, 14 by T/j,. Taken at Wimereux, Pas-de-Calais, France. Host: Scolopendra oraniensis (africanaYerh.) Habitat: Intestine. NINA GIAEDI CORSICUM (Leger and Duboscq) Sokolow [Figure 31] 1903 Pterocephalus Giardi corsicum Leger and Duboscq 1903a :333 1911 Nina giardi corsicum Sokolow 1911 :281-2 Nina: Sporonts solitary, very elongate. Length 2/*. Width not given. Ratio length protomerite : total length : : 1 :10. Ratio width pro- tomerite : width deutomerite : : 4.5 : 1. Protomerite bisymmetrical, formed by two long horns which meet at one end and curve upward nearly 90°. Very wide, 4.5 times maximum width of deutomerite. Ex- tending beyond the deutomerite three times as far on one side as on the other. The periphery of the horns densely set with a row of small denticles with long slender filaments. The shorter lobes thick and blunt. A pseudo-nuclear vacuole near the apex of the opposite lobe, 1. e. at the end of fusion. Protomerite transparent. Deutomerite regularly 84 ILLINOIS BIOLOGICAL MONOGRAPHS [294 cylindrical, tapering slightly and ending bluntly. Nucleus large, spheri- cal. Cyst and spores not known. Taken on the island of Corsica. Host : Scolopendra oraniensis lusi- tanica Verh. Habitat : Intestine. This species differs from N. giardi type only in that a) it attains but half the length of the former, b) the confluent lobes of the protomerite are upturned further in the adult, and c) the lobes of the protomerite are shorter and blunter. NINA INDICIA Merton [Figure 33] 1911 Nina indicia Merton 1911 :119-26 Nina: Sporonts solitary, elongate. Length 500/x - 1500/*. Width not given. Ratio length protomerite : total length : : 1 : 20 ; width pro- tomerite : width deutomerite : : 4 : 1. Protomerite bilaterally symmetri- cal, low and very broad, eight times as wide as high, formed of two long sinuous narrow plates separated at one end for a very short distance. Each bearing a narrow ridge at the upper margin set on both sides with short sharp teeth. The two ridges never confluent but nearly parallel throughout their length. Deutomerite elongate, irregularly cylindrical, dilated a short distance below the septum and tapering from the middle to a long slender and pointed posterior extremity. Endocyte dense in deutomerite, much less dense in protomerite. A deeply staining vesicle at one end of protomerite. Nucleus spherical with chromatin arranged in one convoluted band. Cyst and spores not described. Taken at Heidelberg, Germany. Host: Scolopendra suispinipes Leach. Habitat : Intestine. BCHINOMERA HISPIDA (Schneider) Labbe [Figure 32] 1875 Echinocephalus hispidus Schneider 1875 :293-4 1899 Echinomera hispida Labbe 1899 :16 Echinomera: Sporonts solitary, obese. Measurements not given in the literature. Ratio length protomerite : :total length : : 1 : 7 to 1 : 11 ; width protomerite : :width deutomerite : : 1 : 2 to 1 : 2.4. Pro- tomerite broad, flattened, surmounted by a persistent epimerite in the form of an irregular asymmetrical cone as broad at its base as the proto- 295] STUDIES ON GREGARINES— WATSON 85 merite and terminating in an eccentrically placed point. Sides of this cone set with eight digitiform, upwardly directed processes. Deutome- rite regularly ellipsoidal, widest in the anterior half or nearly globular, terminating in a broadly rounded extremity eight to ten times the length of the epimerite and protomerite together. Endocyte dense, finely granular, with spherical karyosomes. Cysts are described in the liter- ature as spherical, dehiscence by simple rupture. Spores elongate cylin- drical, united in chains. Dimensions not given. Taken at Paris, France ; Cambridge, Mass. ; Wyncote, Pa. ; Raleigh, N. C; and Boulder, Colo. Hosts: LithoMus forficatus Linn. (L. for- cipatus) and LitKobius coloradensis (Cock.) Habitat: Intestine. Crawley (1903:52) found this gregarine rather common in Litho- hius forficatus in eastern United States, and Ellis (1913 :465) found it in the West. Neither gives figures of the species. Since Schneider gave no dimensions, these writers based their determination on a com- parison of their material with his figures. Ellis gives these measure- ments: length 180/i, width 80/i. He says " processes of the epimerite disappearing shortly after the animal frees itself from the intestinal wall of the host, but the conical part persists in the spo- ront stage, giving a symmetrical margin to the front of the protomerite." "In some specimens the ratio of the length of the protomerite to the length of the deutomerite was as low as one to seven, while Schneider's original figures give it as one to eleven or more. Other specimens seemed intermediate between E. hispida (Schn.) and E. horrida (Leger). It seems probable then that E. hor- rida (Leger) is synonomous with E. hispida, leaving a single species in this genus." That Ellis found the ratio of length protomerite : length deutomerite as low as 1 : 7 is not out of harmony with Schneider's proportions of E. hispida, for the latter says "Deutomerite huit a dix fois environ plus long que le segments superieure reunis .'' E. horrida is much more nearly globose than such proportions indicate and there is no good argument for considering the two species synony- mous. Half a dozen specimens of Lithobius forficatus were examined at Oyster Bay, L. I., in October, 1915 and three of them were found to be parasitised with this species. (Figs. 270, 272). From ten to fifty adult parasites were found in the intestine of each host. This species is readily recognized by its intense black color. The specimens are small, the maximum length seen being 330/*, and the maximum width 86 ILLINOIS BIOLOGICAL MONOGRAPHS [296 i20fi. The ratio of length protomerite : total length was 1 : 7 and the ratio of width protomerite : width deutomerite was 1 : 2. The spo- ronts are solitary, and characterized by the possession of a short eccen- tric conical projection from the protomerite, which is slightly mobile. The protomerite is constricted conspicuously in a horizontal direction at about its middle portion. The protoplasm above this constriction is sparse and transparent; below, it is a little more dense and tan; in the deutomerite it is very dense and black, and the nucleus is not visible. Cysts were found to be ovoidal in shape and measured 320 by 270/t. Spores were not seen. A table of measurements in which all dimen- sions are in microns is given here: Length sporont 330 330 270 Length protomerite 40 50 40 Length deutomerite 290 280 230 Width protomerite 50 60 60 Width deutomerite 120 120 120 Ratio length protom. : total length 1 :8.2 1 :6.6 1 :7 Width protom. : width deutomerite 1 :2.4 1 :2 1 :2 ECHINOMEEA HOERIDA (Leger) Watson 1899 Echinocephalus horridus Leger 1899 :390-5 1911 Echinocephalus horridus Sokolow 1911 :281 1916 Echinomera horrida Watson (This paper) Bchinomera : Sporonts ovoidal, almost spherical, 100-150/* in length. Width not given. Protomerite in shape of a narrow elongate blunt cone, the apex eccentric and carrying a papilla which represents a iprimitive epimerite. Cysts spherical or cylindrical, rounded at ends. Taken at Wimereux, France. Host: Lithohius calcaratus Koch. Habitat : Intestine. ACUTISPORA MACROCBPHALA Crawley [Figure 34] 1903 Acutispora macrocephala Crawley 1903a :632-3 Acutispora: Sporonts solitary, elongate. Maximum length 600/*, width not given. Ratio length protomerite : total length :: 1 : 3; width protomerite : width deutomerite : : 1 : 1.3. Protomerite one- 297] STUDIES ON GREGARINES— WATSON 87 third the length of the sporont. Conical papilla at apex, deep con- striction in posterior third and a constriction of equal depth at septum. Deutomerite just behind septum wider than protomerite just in front of it, regularly conical, tapering from shoulder to a blunt point. Endo- cyte dense. Nucleus nqt visible. Cysts spherical, 410/t in diameter, dehiscence by pseudocyst. Spores navicular, slightly curved, slender, two integuments, thin and blunt refractile rod of endocyte at each end, 6/* long ; spores 19 by 4/*. Taken at Ealeigh, N. C. Host: Lithobius forficatus L. Habitat: Intestine. The genus Acutispora was created by Crawley for this unique species. TBICHOEHYNCHUS PULCHER Schneider [Figures 35, 36] 1882 Trichorhynchus insignis Schneider 1882 :439-42 1882 Trichorhynchus pulcher Schneider 1882 :439-42 1889 Gregarina megacephala Leidy 1889 :10-11 1899 Trichorhynchus pulcher Labbe 1899 :16 Trichorhynchus: Sporonts solitary, elongate, length 420 to TSO/x; width 240/x. Ratio length protomerite : total length : : 1 : 4 to 1 : 7. Width protomerite : width deutomerite : 1 : 1 to 1 : 1.6. Bpimerite nearly half the total length of body without it. Protomerite conical, rounded at summit. Slight constriction at septum. Deutomerite just below septum same width as protomerite just above it, widest in ante- rior third. Constricted below middle portion then dilated and ending in a broad but sharply pointed cone. Bpimerite a very long flexible 'tongue' proceeding from the apex of the protomerite, slightly dilated at the extremity. Endocyte in both parts dense. Nucleus ovoidal with one large karyosome. Cysts ovoidal, 316 by 303/;i. Dehiscence by pseu- docyst. Spores cylindrical, rounded at ends, 9.7 by 5.8/^. Taken at Poitiers, Prance; Philadelphia, Pa. Hosts: Scutigera, sp. ; Scutigera forceps (Raf.) (Cermatia f.). Habitat: Intestine. This gregarine was described by Schneider under the name T. in- signis, but his references to his plates are to figures of T. pulcher. It was probably an error in the proof which was accountable for the incorrect naming of the species, for the name of the species immediately preceding is Lophocephalus insignis. Labbe referred to the species as T. pulcher. 88 ILLINOIS BIOLOGICAL MONOGRAPHS [298 Crawley referred the gregarine which was described by Leidy as G. megacephala (Fig. 35) to the present species because of the elongate appendage on the protomerite. That this position is correct is attested by the fact that Crawley himself found the species, the specimens agree- ing with Schneider's figures and with the dimensions as given by Leidy, Crawley's description is as follows: "This form is well described by A. Schneider whose figure also is excellent, giving a very accurate idea of the actual animal. Schneider, however, gives no dimensions, while Leidy says that the dimensions vary from 420 to 750 microns, these figures agreeing very closely with those which I obtained. "My own ottservations on this species show it to be an active, very poly- morphic gregarine, with the ability to undergo extensive alterations in shape. Thus, the anterior end of the protomerite, normally a blunt curve, frequently protrudes in a long tongue-shaped process. The peristaltic movement so frequently dis- placed by gregarines, may, in this species, pass forward as well as backward. This indicates that here the contractile elements are capable of operating as well in one direction as another, which is certainly not the case in most polycystid gregarines. Fusion, preparatory to encystment, was seen to take place 'head to head.' " Leidy 's brief account of the species is as follows: "One morning I found a fine Cermaiia forceps in my bedroom. It was — species which may be named Gregarina megacephala. The body is elongated ovate and acute or short clavate and obtuse with an unusually large ovoid and often constricted head, surmounted by a small rounded or elongated appendage. Length 0.42 to 0.75 mm. by 0.24 broad; head about one-fourth the length of the body. It approximates Dufouria agilis of Schneider, found in the larvae of a Hy- dracantharis.'' The latter species lacks the elongated proboscis; it is now known as Legeria agilis (Schn.) Labbe. For description and drawing, see chapter on Coleoptera. RHOPALONIA GEOPHILI Leger [Figure 51] 1894 Bhopalonia geophiU 1896 Bhopalonia geophili Leger Leger 1894:1285-88 1896:29 Rhopalonia: Sporonts solitary, dicystid, obese. Widest at ante- rior end, tapering to a point. Length 500/*. Epimerite a large hyaline subspherical plate with a corona of ten to fifteen backwardly directed digitiform processes placed above the protomerite on a short neck. Bndocyte with large yellow-orange granules. Nucleus ovoidal, contain- ing several karyosomes. Cysts spherical, 200 to 250/t, the fertile haK brown, the sterile half white, a black equatorial band marking the future 299] STUDIES ON GREGARINES— WATSON 89 line of dehiscence. Spores cylindrical, rounded at ends, double waUed, 16 by 6.5/x. Taken in Provence, France and on the island of Corsica. Hosts: Himantarium gabrielis Linn. (Oeophilus g.); Stigmatogaster gracilis Meinert. Habitat : Intestine. This parasite is peculiar in having no septum in the adult sporont and thus no protomerite and deutomerite. A rudiment of a protomerite is indicated by a finely granular yellow mass at the proximal end of the body, separated from the rest of the sporont by a clear area. Leger thinks this genus is transitional between the Cephalina and the Acepha- lina. His words are as follows : "La Gregarine est done, au point de vus evolutif, une dicystidee vraie, c'est-a- dire n'ayant jamais plus de deus segments; auu apparail de fixation caduc et un segment unique persistants (pseudo-monocystis) representant a la fois le proto- merite et le deutomerite des tricystides. EUe se rapproche en cela des gregarines intestinales des vers marine." Leger and Duboscq (1903:311) found a parasite on the island of Corsica which may be the Bhopalonia geopMU of Leger. "Les Stigmatogaster d'Ajaccio contenaient dans leur intestin de rares spo- radin en forme de toupie, surmountes au pole anterieur d'un plateau circulaire borde d'un Wourrelet saillant. Nous les rapportons avec quelque doute an Rhopa- lonia geophili Leger, frequent dans les Stigmatogaster gracilis de Provence et dont les sporadins sont generalement de forme plus allongee." RHOPALONIA STELLA Leger 1899 Bhopalonia stdla Leger 1899 :390-5 Rhopalonia : Sporonts solitary, ovoidal, elongate or spindle shaped. Length about 130/^, width not given. Body not differentiated into proto- merite and deutomerite. The epimerite is like that of B. geophili Leger and " — rapelle assez bien une fleur de syantheres." (Sokolow 1911 :281). Host : Himantarium gabrielis Linn. Habitat : Intestine. The comparison of the epimerite with the flower of one of the Com- positae is a good one, as seen in Figure 51. 90 ILLINOIS BIOLOGICAL MONOGRAPHS [300 ACTINOCEPHALUS STEIATIUS Leger and Duboscq [Figure 37] 1903 Actinocephalus striatus Leger and Duboscq 1903a :334-5 Aetinoeephalus : Sporonts solitary, minute. Length 30-35/t. Width not given. Ratio length protomerite : total length : : 1 : 4 ; width protomerite : width deutomerite : : 1 :.7. Protomerite wider than deuto- merite, dome shaped, broadly rounded in front with a small flattened cir- cular papilla surrounded by a circle of small teeth. Constriction at sep- tum, which is curved upward. Deutomerite irregularly cylindrical, term- inating in a sharp cone. Bpicyte marked with very apparent longitudinal striations, from whence the name. Nucleus ovoidal with its longitudinal axis perpendicular to that of the body. Cyst and spores unknown. Taken in Provence, France. Host: Scolopendra cingulata La- trielle. Habitat: Intestine. This gregarine is placed in the genus Actinocephalus from the character of the dentate papilla of the protomerite. " au sommet du protomerite fait saillie un petit bouton aplati, a bord regu- lierement festonne, comme dentele, au centre dupuel s'eleve un rostre mobile asset droit. C'est la I'epimerite qui, comme on le voit, presente de grandes analogies avec celui des Actinocephalus." ACTINOCEPHALUS DUJARDINI Schneider [Figures 38, 39, 40] 1875 Actinocephalus dujardini Schneider 1875 :589-90 Actinocephalus: Sporonts solitary, rather obese. Length and r width not given. Ratio length protomerite : total length : : 1 : 2.4 ; width protomerite : width deutomerite : : 1 :1. Protomerite very large, cylindrical, longer than wide, nearly one third total length of sporont, terminating in a truncated cone, the apical region being hyaline, slight constriction at septum. Deutomerite widest just behind the septum and tapering gradually to a sharp point. Endocyte of equal density in pro- tomerite and deutomerite. Epimerite a globose sessile body resting on the apex of the protomerite, drawn out in its apical region to a short neck upon which is set a flat corona of 16 to 20 backwardly directed rigid spines. Nucleus small, spherical. Cyst and spores not known. Taken at Paris, France. Host : Lithobius forficatus Linn. (L. for- cipatus). Habitat: Intestine. Crawley (1903 :55) records finding this little gregarine several times in L. forficatus. He gives no drawings and does not state where it was taken. 301] STUDIES ON GREGARINES— WATSON. 91 AMPHOROCEPHALUS AMPHORELLUS Ellis [Figures 45, 46] 1913 Amphorocephalus amphorellus Ellis 1913 :463-4 Amphorocephalus : Sporonts solitary, elongate, length 500 to 970/*, width not given. Ratio length protomerite : total length : : 1 : 1.7 ; width protomerite : width deutomerite : 1 : 2.5. Protomerite dome shaped, broadly rounded in front, a distinct constriction near middle. Deutomerite cylindrical, tapering slightly to a sharp point. Endocyte dense, nearly black. Epimerite flask-shaped with fluted apical disc, ses- sile on the protomerite, persisting on large free cephalonts. Nucleus not noted. Cyst and spores not seen. Taken at Boulder, Colo. Host: Scolopendra heros Giard. Habi- tat : Intestine. This genus contains the unique species above. It is characterized by the flask-shaped epimerite with finger-like processes at the apex and by the protomerite having a constriction at the middle, extending hori- zontally around the same. HOPLORHYNCHUS ACTINOTUS (Leidy) Crawley [Figures 42, 43] 1899 Gregarina actinotus 1903 Hoplorhynchus actinotus 1913 Amphorocephalus actinotus Hoplorhynchus: Sporonts solitary. Maximum length recorded that of Leidy, 520/*, maximum width 80/*. Crawley's maximum recorded length, 485/i, width 105/i. Ratio length protomerite : total length :: 1 :9 (Leidy) to 1:12 (Crawley); width protomerite : width deuto- merite ::1 :2 (Leidy and Crawley). Protomerite dome shaped, twice as broad as high. Deutomerite roughly triangular, wider than protome- rite at septum. Attaining maximum width at shoulder, thence taper- ing to a more or less sharp point. Epimerite 80 to lOO/t long, vase shaped, broadest near base and tapering to a neck where it again widens into a broad disc of short digitform processes from 8 to 20 in number. Craw- ley says : " amphora shaped. Differentiated in front into four dichotomously branched lobes. In the small animals making up nearly 1/2 the total length; in the adults from 1/4 to i/s of the total length." Leidy 1889:10 Crawley 1903 :55-56 Ellis 1913b :277 92 ILLINOIS BIOLOGICAL MONOGRAPHS [302 Endocyte dense and opaque. Nucleus ovoidal, diagonally placed. Cyst and spores not known. Taken at Philadelphia, "Wyncote and "Wallingford, Pa., and Raleigh, N. C. Hosts: Scolopocryptops sexspinosus (Say) and Scolopocryptops sp. Habitat : Intestine. Crawley (p. 56) says: "Apparently in this gregarine the septum tends to disappear. It is much more evident in some cephalonts than in others, and in one sporont seen no septum could be made out, and the endocyte of the protomerite was not distinguishable from that of the deutomerite." Ellis (1913b) placed this gregarine in his genus Amphorocephalus. He characterizes the genus as follows: "Protomerite with a constriction near the middle dividing it into two lobes, the anterior of which is the smaller ; epimerite longer than wide, but not extremely elongate, widest in its posterior third, narrowed at its junction with the protomerite terminating in a somewhat concave enlargement, the edge of which has a fluted appearance because of the presence of numerous small finger-like processes; deu- tomerite elongate." It is readily seen that the species in question does not fit this generic diagnosis for the following reasons: 1) the protomerite is not con- stricted in the middle, with a small anterior part; 2) the epimerite is elongate, from two to four times as long as wide (in EUis' described species it is but little longer than wide, 1 : 1.2) ; 3) the apex does not terminate in a broad disc, the edge of which has a fluted appearance, be- cause of the presence of numerous small finger like processes, but termi- nates in a disc edged with dichotomously branched distinctly separated digitiform processes, from eight to twenty in number; 4) the deutome- rite is not elongate as in Ellis' figure, in which it is from eighteen to twenty-two times the length of the protomerite, but is only from six to twelve times the length of the protomerite. I have therefore replaced the species in the genus designated by Crawley. HOPLORHYNCHUS SCOLOPENDRAS Crawley [Figure 41] 1903 Eoplorhynchus scolopendras Crawley 1903a :636-7 1913 Amphorocephalus actinotus Ellis 1913b :277 Crawley's description of the species is quoted: "This species is created for a gregarine parasitic in Scolopendra woodi Mein- ert from Raleigh, N. C. Two specimens were present. One of these, when first 303] STUDIES ON GREGARINES— WATSON 9Z seen, was a balloon-shaped sac, zso^ long by 200 broad. The epicyte and sarco- cyte were each nearly or quite 3ft. thick, and the former was plainly marked with longitudinal striations. Both of the individuals were very flexible, readily chang- ing shape and showing extensive contortions. After having Ween upon the slide for perhaps an hour, the parasites became quiescent and assumed what was prob- ably something like the typical shape. The larger then measured 825^ long by 120 broad. The anterior end, as shown in figure 19, was much narrower than the bal- ance of the animal, but it is somewhat questionable if this narrowing is perma-- nent. A distinct septum extended across this narrower region, cutting off a portion of granular entocyte. Backward from the broadest portion, the animal's body ta- pered gradually, ending behind in a point. This species is placed in the genus Hoplorhynchus on account of its close resemblance to H. actinotus Leidy and its occurrence in a centipede related to Scolopocryptops, the host of the latter." Its position is doubtful from insufficient evidence and will not re- main authentic unless corroborated and described in more detail by some future worker. EUis included this species with H. actinotus under the name Am- phorocephalus actinotus (Leidy). I have referred the species to the original position. The protomerite does not have the constriction neces- sary to place it in the genus Amphorocephalus. SPECIES OF UNCERTAIN DETBEMINATION TRICHOEHYNCHUS LITHOBII Crawley [Figure 44] Crawley's statement (1903a :637) eoneerning this species is as fol- lows: "This animal, which is apparently specifically distinct from any other gregarine parasitic in Lithobius, was found in a specimen of that centipede from Raleigh, N. C. An epimerite was not found. The protomerite was subcordiform, and displayed in front a differentiation the exact nature of which could not be determined. The deutomerite varied consideraMy in shape, the animal being quite polymorphic. Both epicyte and sarcocyte were distinct and of about equal thickness. The septum was thick and curved backward. The endocyte was not dense; the nucleus large, with several karyosomes. The largest individual seen was ips^u long." There seems to be no basis for placing the parasite in the named genus. None of the characteristics of the genus are named above, the elongate epimerite, ovoidal cysts which dehisce by pseudocyst, cylindrical spores. Enough data are lacking so that the species cannot be definitely placed in any genus. 94 ILLINOIS BIOLOGICAL MONOGRAPHS [304 A parasite is described by Leger and Duboscq (1903a :312) but not named. It was found on the island of Corsica, in Chaetechelyne vesu- viana Newport. Their statement in full follows : "Sur plusieurs individis examines, un seul (d'Ajaccio) etait parasite par une Gregarine recontree seulement au stade de sporadin. Sous cette forme, la Gregarine est allongee et mesure loo/i. Le deutomerite est, dans sa partie anterieure, plus large que le protomerite dont il atteint S ou 6 f ois la longuer, puis il va en s'attenuait pour se terminer en pointe pousse. Ces caracteres ne sont pas suffisants pour rap- porter ces sporadins a un Rhopalonia plutot qu' a un Actinocephalus." A third species of indeterminate situation is that called by Balbiani Dactylophorus sp. (1889:41). This species has been discussed in detail under the heading Dactylophorus robustus (Leger) Labbe, and is illus- trated in Figure 47. A fourth species of doubtful position is that described by Kolliker as Gregarina scolopendra (Figure 48). See discussion under Nina gra- cilis Grebnecki. POLYCYSTID GREGARINES IN THE ORTHOPTBRA* Name of Parasite gregarinidae Gregarina oblonga Dufour Gregarina hyalocephala Dufour Gregarina ovata Dufour Gregarina hlattarum Siebold Gregarina locustae Lankester Gregarina oviceps Diesing Gregarina macrocephala (Schn.) Labbe Gregarina panchlorae Frenzel Gregarina acridiorum Leger Gregarina paranensis (Kunckel d' Hercula- ris) Watson Gregarina serpentula deMagalhaes Name of Host Oeipoda stridula Oedipoda migratoriae Gryllus campestris Tridaciylus variegatus Forficula auricularia L. Periplaneta orientalis (L.) Periplaneta americana (L.) Blatella germanica (L.) Dissosteria Carolina (L.) Gryllus abbreviatus Serv. Gryllus americana Blatch. Nemobius sylvestris (F.) Gryllus domesticus (L.) Panchlora exoleta Klug Tryxalis sp. Pamphagus sp. Sphingonotus sp. Schistocera paranensis Periplaneta orientalis (L.) *The parasites are arranged in chronological order under each genus. 305] STUDIES ON GREGARINES— WATSON 95 Gregarina rigida (Hall) Ellis Gregarina kingi Crawley Gregarina longiducta Ellis Gregarina consobrina Ellis Gregarina illinensis Watson Gregarina galliveri Watson ' Gregarina stygia Watson Gregarina nigra Watson Gregarina udeopsylla Watson Leidyana erratica (Crawley) Watson Leidyana gryllorum (Cuenot) Watson Hyalospora roscoviana Schneider Hyalospora affinis Schneider Gamocystis tenax Schneider Hirmocystis gryllotalpa (Leger) Labbe ACTINOCEPHALIDAE Pileocephalus blaberae (Frenzel) Labbe Actinocephalus fimhriatus (Diesing) Ellis INDETERMINATE SPECIES Gregarina conica Dufour Gregarina davini Leger and Duboscq MISCELLANEOUS Gregarina sphaerulosa Dufour Gregarina soror Dufour Melanoplus differentialis (Uhler) M. femur-rubrum (deGeer) M. atlanis (Riley) M. coloradensis ? M. bivitattus (Say) M. angustipennis (Dodge) M. femoratus (Burm.) M. luridis (Dodge) Hesperotettix pratensis Scudder Schistocera americana Burm. Brachystola magna Giard Encoptolophus sordidis (Burm.) Gryllus abbreviatus Serv. Ceuthophilus latens Scudder C. maculatus (Say) Ceuthophilus valgas Scudder Ischnoptera pennsylvanica (deGeer) Gryllus abbreviatus Serv. Ceuthophilus stygius (Scudder) L. VARIOUS ACRIDIDAE Udeopsylla nigra Gryllus abbreviatus Serv. Gryllus pennsylvanica Burm. Gryllus domesticus (L.) Petrobius maratiittus Machiliis cylindrica E. Geoff. Blatella laponica Gryllotalpa gryllotalpa (L.) Blabera clarsiana Sauss. Dissosteria Carolina (L.) Coleoptera and Gryllus Gryllomorpha dalmatina Ocsk. 96 ILLINOIS BIOLOGICAL MONOGRAPHS [306 GEEGAEINA OBLONGA Dufour [Figures 177, 178] 1837 Gregarina oblonga Dufour 1837 :13 1848 Gregarina oblonga Prantzius 1848:195 1851 Gregarina oblonga Diesing 1851:11 1863 Gregarina oblonga Lankester 1863 :94 The only description extant is the original one of Dufour, which is as follows : "Oblonga flavescens conico-cylindroidea ; cephalothorace abdominis quintam partem vix adeaquante. Hab — Oedipodae migratoriae et Grylli campestris. Beaucoup moins conique la G. conique elle a une couleur jaunatre qui ne s't)bserve pas dans les autres especes.'' Here, as in the case of Gregarina condca, Dufour confused more than" one species under a single name. Oedipoda is a genus of the order Dip- tera and also of the Orthoptera. If the Dipteran order is meant, the same species of gregarine would not be looked for in both Diptera and Orthoptera. Such an instance has not yet been recorded for a single species. Dufour 's drawings from both insects are, however, similar and are reproduced in my Figures 177 and 178, although the protomerites are slightly different in their relation to the deutomerites.* Frantzius lists the species as from Oedipda only. He places it in the same genus Gregarina "stets zu zwei aneinander geheftet." Diesing mentions it with hosts as Oedipoda migratoria and 0. stri- dula, and from Gryllus campestris. Lankester gives the host as Gryllus. After this mention, the spe- cies passes out of the literature. I have listed it among the parasites of the genus Gregarina because Dufour states "cephalothorace abdominis quintam partem" and because Frantzius lists it among the parasites with both prinlite and satellite. This species may be identical with Gregarina macorcephala Schn. from the identity of one of the hosts, but the two cannot be correlated. Dufour describes only sporonts and Schneider only cephalonts and un- *I have not attempted to separate the parasite in the two hosts as two species from the meager description we have, but have recorded this species in this chapter as well as in Part III, a list of Polycystid Gregarines, under the Diptera. 307] STUDIES ON GREG ARINES— WATSON 97 til the cephalonts of the former or the sporonts of the latter or both will have been described, the two species must remain separate. The only other parasite described from a host belonging to the sub- family Oedipodinae (Acrididae) is Gregarma locustae Lankester, but the sporonts of the two species are not identical. The second host named is now known as Nemoibius sylvestris (F.). GREGARINA HYALOCEPHALA Dufour [Figures 181, 182] 1837 Gregarina hyalocephala Dufour 1837 :13 1851 Gregarina hyalocephala Diesing 1851 :11 1863 Gregarina hyalocephala Lankester 1863 :94 1899 Gregarina hyalocephala Labbe 1899 :34 Dufour 's description is as follows: "Oblongo-conica ; cephalothorace hemispherico diaphano, abdominis quartam partem subadaequante . Hab. in ventriculo Tridactyli." The species is, from this description, and from the character of the epimerite (Figure 182) quite evidently a member of the genus Grega- rina. Frantzius does not mention the species; Diesing and Lankester merely do so and Labbe places it among his Uncertain Species. GREGARINA OVATA Dufour 1826 Gregarina ovata 1837 Gregarina ovata 1837 Gregarina ovata 1838 Clepsidrina conoidea 1845 Gregarina ovata 1848 Gregarina ovata 1851 Gregarina ovata 1863 Gregarina ovata 1873 Clepsidrina ovata 1885 Clepsidrina ovata 1875 Clepsidrina ovata 1899 Gregarina ovata 1904 Gregarina ovata 1905 Clepsidrina ovata Gregarina: Sporonts biassociative. Measurements not given in any description. Ratio length protomerite : :total length primite :: [Figure 183] Dufour 1826 :18 Dufour 1837:12 Siebold 1837 :408 Hammerschmidt 1838 :356 Desmarest 1845:? Frantzius 1845:95 Diesing 1851 :10 Lankester 1863:94 Schneider 1873 :515-33 Schneider 1875:578-9 Schneider 1885 : ? Labbe 1899:10 Paehler 1904:14-18 Schnitzler 1905 :309 98 ILLINOIS BIOLOGICAL MONOGRAPHS [308 1 : 5 to 1 : 6 ; width protomerite : width deutomerite : : 1 2. Protomerite of primite hemispherical, slightly constricted at septum. Protomerite of satellite flattened. Deutomerite ovoidal, widest below middle in pri- mite, above middle in satellite. Posterior end rounded. Nucleus spheri- cal with many small karyosomes, visible iu vivo. Epimerite a simple hyaline knob. Cysts spherical or slightly ovoidal, dehiscence by sixteen, more or less, spore ducts; spores cylindrical, truncate at ends (not barrel shaped), macrospores and microspores (15.8 by 7.9; 8.3 by 3.7/^.). Taken in France, and in Berlin and Danzig, Germany. Host : For- ficula auricularia L. Habitat : Intestine. Dufour designated as hosts Gryllus campestris and Forficula. He gave a good figure of biassociative sporonts taken from Forficula, and a figure of a single sporont from Gryllus which differs considerably in shape from the other and probably represents another species, although I have not attempted to place it systematically. Siebold accidentally found this species in Forficula but he did not think the organisms were animals, for no motion was observed. Frantzius represented an accurate figure of the species. He named Forficula as host, recognizing Dufour 's error in including a parasite from Gryllus. Diesing indicated that Hammerschmidt had described a synony- mous species, Clepsidrina conoidea, from the same host. He also included as a synonym G. psocorum Sieb. but from the fact that the host, Psocus quadripunctatus, is a Neuropteran, I doubt the authenticity of this state- ment. Siebold 's paper is not available and the conjecture cannot be verified. Schneider agreed with Diesing that Clepsidrina conoidea is a syno- nym of Gregrina ovata. He discussed at length (1873) the cyst forma- tion in this species. In 1885, he worked upon the species in greater de- tail, finding and giving measurements of two kinds of spores. The species was the subject of a monograph by Paehler in 1904. I have examined about fifty specimens of Forficula auricularia L. at Cold Spring Harbor, L. I., without finding parasites. 309] STUDIES ON GREGARINES— WATSON 99 GEEGARINA BLATTARUM Siebold [Figure 184] 1839 Gregarina hlattarum Siebold 1839 :57 1848 Gregarina hlattarum Stein 1848:223 1848 Gregarina Blattarum Prantzius 1848 :193,195 1851 Gregarina Blattarum Diesing 1851:10 1853 Gregarma Blattae orientalis Leidy 1853 :239 1863 Gregarina blattarum Lankester 1863 :94 1875 Clepsidrina hlattarum Schneider 1875:580 1881 Gregarina hlattarum Biitschli 1881 :384-409 1891 Gregarina hlattarum Wolters 1891:115-24 1893 Gregarina hlattarum Marshall 1893 :25-45 1899 Gregarina hlattarum Labbe 1899:10 1900 Clepsidrina hlattarum deMagalhaes 1900 :38-44 1903 Gregarina hlattarum Crawley 1903 :44 1907 Gregarina hlattarum HaU 1907 :149 1913 Gregarina hlattarum Ellis 1913b :265 1913 Gregarina hlattarum Ellis 1913c :83-84 Gregarina: Sporonts biassociative, rather stout bodied, more or less irregular in outline. Length of sporonts 450 to 500/t. Width 185 to 200/i. Ratio length protomerite : total length primite : : 1 : 5 ; width pro- tomerite : width deutomerite : : 1 : 2. Protomerite of primite cylindrical ' in posterior two thirds, rounded anteriorly, no constriction at septum. Very little wider than high. Protomerite of satellite flattened, wider than protomerite of primite, twice as wide as high. Deutomerite irregu- larly cylindrical, widest in posterior half of primite and in anterior half of deutomerite. More or less pointed at posterior extremity. Sarcocyte layer thick. Nucleus small, spherical, (44/x, in diameter — deMagalhaes — ) with from four to six karyosomes. Epimerite a simple hyaline knob. Cysts spherical or ovoidal. Spore duets reach to outside of trans- parent cyst cover. Spore ducts 8 to 10 in number. Spores cylindrical to barrel shaped, truncate at ends, 8.5 by 3.7 and 4 by S/j,. Taken at Danzig, Berlin, Heidelberg, Bonn, and Leipsic, at Paris, at Philadelphia, Pa. and at Rio Janeiro, Brazil. Hosts: Peviplaneta orientalis (L.) (Blattae or.); P. americana (L.) ; Blatella g trmanica (L.) (Ectohia germ.). Habitat: Intestine. This is a remarkably cosmopolitan species, as seen from the loca- tions where it was taken. It is remarkable also in that the name has re- mained almost undisputed since its discovery. 100 ILLINOIS BIOLOGICAL MONOGRAPHS [310 Leidy described briefly Gregarina blattae orientalis from the United States, which species proved to be synonymous with the earlier named species, coinciding in measurements, proportions and host. Schneider gave a brief description, with good figures of an associa- tion and of a dehiscing cyst. Biitsehli admirably described the process of cyst formation from be- ginning to end, a process never before seen and very rarely described siace. Wolters observed some of the nuclear changes in the cyst. Marshall contributed the third long paper on development. deMagalhaes found the species in Brazil in 1900; three years later Crawley found it in the United States, both from the original host. The specimens found by these workers were undoubtedly those of the true old-world G. blattarum. The shape and proportions correspond, and in hosts of the nature of the cockroach, there is little wonder that both host and parasites are widely distributed. GREGARINA LOCUSTAB Lankester [Figure 188] * 1853 Gregarina Locustae Carolinae Leidy 1853 :289 1856 Gregarma Locustae Carolinae 1859 Gregarina fimbriata 1863 Gregarina Locustae 1899 Gregarina locustaecarolinae 1903 Stephanophora locustaecarolinae 1907 Gregarina locustaecarolinae 1913 Gregarina locustaecarolinae Gregarina: Sporonts biassociative. Maximum length of sporonts 350/x, average length 250jm,. Ratio length protomerite : total length pri- mite : : 1 : 6.8 ; vridth protomerite : width deutomerite : : 1 : 1.7. Proto- merite a little more than hemispherical, one and one half times as wide as high. Deutomerite cylindrical, rather square cornered posteriorly, nearly twice as wide as the protomerite. Nucleaus large, spherical, with one karyosome. Epimerite a small rounded knob with a very short neck. Taken at Philadelphia and Wyncote, Pa. Host: Dissosteria Caro- lina (L.) Habitat: Intestine. Crawley recognized (1907) the fact that Leidy described and illus- trated two distinct species under the same name. Leidy 's figures 35 and 36 (1853), the former my figure 188, represent isolated sporonts typical of the genus Gregarina in relative strength and width of proto- Leidy 1856:47 Diesing 1859:730 Lankester 1863 :94 Labbe 1899 :35 Crawley 1903 :54 Crawley 1907 :225 Ellis 1913b :268 311] STUDIES ON GREGARINES— WATSON 101 merite and deutomerite. Associations were not mentioned, however. His figure 37 (Figure 189) is quite different in shape and the epimerite is an inverted eampanular structure furnished with slender upwardly directed digitiform processes. Because of the epimerite, Crawley (1903) placed the species in the genus Stephanohora. In 1907, he found cepha- lonts in locusts quite unlike those seen by Leidy. They possessed simple knobbed epimerites like those of other species of the genus Gregarina. He saw the sporonts also, and they compared favorably in length with those described by Leidy. At the same time, Crawley substantiated Leidy 's discovery of the digitform epimerite, for he found similar ceph- alonts and also sporonts which compared. Thus it was discovered that two species were involved, the one a true Gregarina, the other not. The latter species is now known as Actinocephalus fimbriatus (Diesing) EUis. The name of the species as given by Leidy is a trinominal and can- not stand. The first binominal name applied to the species was that of Lankester, which must be used to designate the species. The name used by Diesing, Gregarina fimbriata, applies to the species ActinocepJialus pachydermus for he says proboscis "digitato-fimbriata". GEBGARINA OVICEPS Diesing [Figures 191, 192] 1853 Gregarina Achetae ahhreviatae Leidy 1853:238 1856 Gregarina Achetae ahhreviatae Leidy 1856:47 1859 Gregarina oviceps Diesing 1859:730 1863 Gregarina Achetae Lankester 1863 :94 1899 Gregarina achetaeahbreviatae Labbe 1899:35 1903 Gregarina achetaeahbreviatae Crawley 1903 :45 1903 Gregarina achetaeahbreviatae Crawley 1903a :639 1907 Gregarina achetaeahbreviatae Crawley 1907 :220-l 1913 Gregarina achetaeahbreviatae Ellis 1913b :266 1915 Gregarina achetaeahbreviatae Watson 1915:34 Gregarina: Sporonts biassociative, obese. Maximum length 500/1. Average sporonts 450|u, in length, 225/* in width. Ratio length proto- merite : total length primite : : 1 : 3 ; width protomerite : width deuto- merite : : 1 : 1.1. Protomerite hemispherical to subglobose, width twice the height. Slight constriction at septum. Deutomerite stout-bodied, nearly as wide as long. Widest at shoulder where it is very little wider than protomerite. Posterior end truncate. Epimerite undescribed. Bn- docyte dense in deutomerite, less so in protomerite. Nucleus not visible 102 ILLINOIS BIOLOGICAL MONOGRAPHS [312 in vivo and not seen. Cysts spherical, 250/i in average diameter. Spore ducts 2 to 5, of maximum length 1000/t. Spore barrels shaped, 4.5 by 2.25^. Taken at Haverford and Philadelphia, Pa., Beach Haven, N. J., Douglas Lake, Mich., Urbana, 111., Oyster Bay, L. I. Hosts: Gryllus dbbreviatus Sew. (Acheta abhreviata) ; G. americanus Blaich. Habitat: Intestine. Leidy's drawing of the species (1853), my figure 191, represents the same gregarine as that described by later writers. But later drawings from Leidy's unpublished manuscript, Crawley's 1903 paper (PI. Ill, Figs. 34, 35), show two distinctly different species, one associative and the other not. Crawley confused the two in his description, under the name Gregarina achetaedbbreviatae. In 1907 he described two distinct species, however, one the Gregarina achetaeabbreviatae of Leidy and a new Stenophora erratica, for the solitary species. The latter I have transferred to a new genus Leidyana. For description, see under L. erratica. EUis found this species at Douglas Lake, Mich., and I have found it from material taken at Haverford, Pa., Urbana, 111., and Oyster Bay, L. I. Diesing changed the name of Leidy's species to Gregarina oviceps without giving explanation therefor and since this is the oldest binom- ial name used, the species must bear this name. GEBGAEINA MACROCBPHALA (Schneider) Labbe 1875 Clepsidrina macrocephala Schneider 1875 :674 1882^ Clepsidrina macrocephala Schneider 1882:442 1887 Clepsidrina macrocephala Schneider 1887 :73 1895 Clepsidrina sp. Cuenot 1895 :321 1897 Clepsidrina gryllorum Cuenot 1897 :54 1899 Gregarina macrocephala Labbe 1899:10 Gregarina: Sporonts biassociative. The following synopsis refers to the cephalont only, there being no available description of the sporont. Ratio length protomerite : total length primite :: 1 : 5; width protomerite : width deutomerite :: 1 : 1.2. Protomerite rounded laterally, as wide as high. Constriction at septum. Epimerite super- imposed upon protomerite on a short stout neck. Epimerite a large hyaline ovoidal body a little longer than the protomerite of the cepha- lont. Deutomerite elongate cylindrical, tapering suddenly to a sharp 313] STUDIES ON GREGARINES— WATSON 103 point. Endocyte with large irregularly arranged protoplasmic granules. Cysts spherical, dehiscing by spore ducts. Spores doliform. Taken in Aisne, Indre-et-Loire, and Vienne, France. Hosts: Nemobius sylvestris (F.) (Gryllus s.); Gryllus domesticus L. Habitat: Intestine. In 1875 Schneider merely mentioned the character of the epimerite of the undescribed species. In 1882 he described the cephalont only. This species may be identical with Gregarina dblonga Dufour, from the same host. It is impossible, however, to correlate the two species for the reason that Dufour described only sporonts and Schneider only cephalonts. Leidyana gryllorum (Clepsidrina g.) was erroneously included with this species by Labbe. For discussion, see under L. gryllorum. , GEEGARINA PANCHLORAE Frenzel [Figure 187] 1892 Gregarina pancMorae Frenzel 1892 :290-300 Gregarina: Sporonts biassociative, long and slender. Sporonts 180/i long, 35/4 wide. Protomerite of satellite cylindrical, constricted slightly in anterior half. Deutomerite of primite fits into a deep de- pression in anterior end. Deutomerite cylindrical. Nucleus spherical, 18 to 20/i in diameter, with one karyosome. Taken in Cordoba, Argentina. Host: Panchlora exoleta Klug. Habitat : Intestine. Frenzel gave a meagre description and but one drawing of this species, illustrating only the manner in which the protomerite of the satellite fits into the deutomerite of the primite. This part of the asso- ciation is intermediate between that of the same portion of G. serpentula deMagalhaes, as shown in his two figures, the one of a young, the other of a mature, association. (Figs. 185 and 186.) The lengths of the two species are, however, widely at variance so the species are not identical. 104 ILLINOIS BIOLOGICAL MONOGRAPHS [314 GEBGAEINA ACRIDIORUM Leger 1893 Clepsidrina acridiorum Leger 1893:811-13 1896 Clepsidrina acridiorum Leger 1896:27-30 1899 Oregarina acridiorum Labbe 1899 :10 Gregarina: Sporonts biassoeiative, cylindrical. Maximum length of individual lOOO/^i; minimum length 400/*, width 160/*. Ratio length protomerite : total length :: 1 : 5; protomerite subglobular in pri- mite, depressed at anterior end in satellite. Deutomerite cylindrical, rounded at posterior end. Sarcocyte thick, especially in protomerite near septum. Bndocyte yellow orange. Epicyte longitudinally striated. Myocyte well developed. Nucleus spherical, with many small karyo- somes. Epimerite a simple spherical hyaline button on a short stalk. Cysts spherical, 500/* in diameter. Spore ducts 12 to 15 in num- ber, very long, yellow orange at base. Spores extruded in long chains. Spores doliform, 7.6 by 3.3/*. Taken at Nemours, Algeria, and in Provence, France. Hosts : Va- rious Acrididae, especially Tryxalis sp. (Truxalis), PampKagus sp. and Sphingonotus sp. Habitat: Intestine. GREGARINA PARANENSIS (Kunckel d'Hercularis) Watson 1899 Clepsidrina paranensis Kunckel d'Hercularis 1899:622 1916 Gregarina paranensis Watson (This paper) Gregarina: Sporonts biassoeiative. Length not given. Deuto- merite four times as long as protomerite. Ellipsoidal, pale yellow. The author says the species differs from G. acridiorum Leger in having the deutomerite ellipsoidal instead of cylindrical, and the endo- cyte pale yellow instead of yellowish red. He says between the moults of the insect the parasites are abundant. They diminish in number after each moult. Taken at Parana, Argentina. Host: Schistocerca paranensis. Habitat : Intestine. GREGARINA SERPENTULA deMagalhaes [Figures 185, 186] 1900 Gregarina serpentula deMagalhaes 1900:140-44 Gregarina: Sporonts biassoeiative, slender, elongate. Maximum length association 1200/*, width 180/i. Average length 800/*, width 60/*. 31S] STUDIES ON GREGARINES— WATSON 105 The protomerite is SO/oi long. Ratio length protomerite : total length : : 1:8; width protomerite : width deutomerite : : 1 : 1.3. Protomerite subspherical, flattened at septum, width equal to length. Constriction at septum. Deutomerite elongate cylindrical broadly rounded behind. Nucleus spherical with several karyosomes. Young associations more slender, protomerites greatly attenuated. Cysts spherical or ovoidal. Taken at Rio Janeiro, Brazil. Host: Periplaneta orientalis (L.). Habitat: Intestine and coelom. de Magalhaes names the species serpentula from the manner of movement. "- a m'ont paru rappeler la forme de la tete d'un serpent et ses mouvements." The author found instances in which more than two sporonts were attached : "Celli-ci (espece) fournit frequement des examples d'association de plusieurs invidis disposes en file; deux trois et plus sont accoles par leurs extremites op- posees. D'autres fois, ils forment des groupes constitues d'un plus gros exeniplaire, a I'extremite posterieure duquel sont accoles deux, trois, cinq satellites plus petits." These phenomena are observed in rare instances throughout the genus Gregarina. This species is quite distinct in characteristics from G. ilattarum Sieb., from the same host and its authenticity is not questioned. GREGARINA RIGIDA (Hall) Ellis [Figures 194, 197, 198, 271, 290-333, 336-338] 1907 Hirmocysiis rigida Hall 1907 :149-174 1907 Gregarina melanopli Crawley 1907 :223 1913 Gregarina rigida Ellis 1913b :267 1913 Gregarina melanopli Ellis 1913c :82-3 1915 Gregarina rigida Watson 1915:34-35 Gregarina: Sporonts biassociative, rather stout bodied. Maxi- mum length of association 1425/i,, average length 550/a. Sporonts 250 to 750/t long, 130 to 210/i wide. Ratio length protomerite : total length : : 1 : 3 to 1 : 6 (primite) ; length protomerite : total length (satel- lite : : 1 : 5 to 1 : 16 ; width protomerite : width deutomerite : : 1 : 1.4. Protomerite somewhat flattened, width sometimes three times the height, generally less. Constriction at septum more or less indistinct. Deutomerite cylindrical or barrel shaped, little wider than protomerite, ending in a broadly rounded or flattened square cornered extremity. 106 ILLINOIS BIOLOGICAL MONOGRAPHS [316 Endocyte very dense and brownisli yellow in deutomerite, tan in pro- tomerite. Epimerite a small spherical hyaline knob. Cysts yellow orange, 300/t in average diameter, spore ducts short, ten or more in number. Spores extruded in chains, barrel shaped, 5 by 8/*. Taken at Wyneote, Pa. ; Douglas Lake, Mich. ; Lincoln, Neb. ; Colo- rado Springs, Colo. ; Boulder, Colo. ; Urbana, lU. ; and Oyster Bay, L. I. Hosts Melanoplus femoratus (Burm.) ; M. luridis (Dodge) ; M. femur-rubrum (de Geer) ; M. attantis (Riley) (M. atlantis); M. differ- entialis (Uhler) ; M. coloradensis ? ; M. angustipennis (Dodge) ; En- coptolophus sordidis (Burm.); Schist ocerca americana Burm.; M. hi- vitattus (Say) ; Hesperotettix pratensis Scudder; Brachystola magna Giard. Location: Intestine and caeca. This species was first described by Hall as Hirmocystis rigida. He mentioned dehiscence of the cysts by simple rupture, and he saw neither the spores nor the epimerite. The only character in common with the genus Hirmocystis was the simple rupture of the cysts, and this char- acter is possessed by some thirty genera. Crawley (1907) published an article two months later describing a new species, Gregarina melanopli, which proved to be the same species. He found that dehiscence occurred by means of numerous spore ducts. The epimerite was still unknown. Ellis changed the name of the species to Gregarina rigida (Hall). I have taken parasites of this species from various Acrididae in material from Colorado Springs, Lincoln, and Urbana. In three in- stances specimens were recovered from M. femur-rubrum at Oyster Bay, L. I. (Fig. 271). Although hundreds of grasshoppers have been exam- ined at the latter place, infection has been found but these few times, and then very few parasites were present. Cysts have developed, aU. with numerous long spore ducts. Typical spores were extruded. GREGARINA KINGI Crawley [Figure 193] 1907 Gregarina Ungi Crawley 1907 :221-3 1913 Gigaductus Ungi Ellis 1913b :271 Gregarina : Sporonts biassociative, rather stout bodied. Maximum length of associations 350/t. Sporont measurements not given. Ratio length protomerite : total length : : 1 : 3 ; width protomerite : width deutomerite : : 1 : 1. Protomerite saddle-shaped, i.e. broadly dilated aud nearly flattened apically, with deep constriction just below middle, 317] STUDIES ON GREGARINES— WATSON 107 dilated again less extremely below. Widest part twice the width of narrowest part. Protomerite equal in length to its greatest width, a slight constriction at septum. Deutomerite widening out rapidly from septum to shoulder, and quite regularly cylindrical from thence down- ward. Very broadly rounded at distal end. Nucleus spherical, small. Bndocyte not dense. Cysts spherical, 110/i in maximum diameter, one spore duct only, spores barrel shaped, 5 by 2.75;n in dimensions. Taken at Wyncote, Pa. Host: Oryllus abhreviatus ^&rv. Habitat: Intestine. EUis placed the species in question in the genus Gigaductus, origi- nally created by Crawley himself for Gigaductus parvus. I have al- lowed this genus to drop out, removing the type species to the genus Gregarina, for its differentiating character was the large single spore duct. A discussion of the matter is found in the chapter on Coleoptera, under the species Gregarina parva. This species has been replaced in the genus to which it was origi- nally assigned. GEEGAEINA LONGIDUCTA EUis [Figure 195] 1913 Gregarina longiducta Ellis 1913c :78-82 Gregarina: Sporonts biassociative, obese. Length of associations 800 to 900/i. Eatio length protomerite : total length primite : : 1 : 3.5 ; width protomerite : width deutomerite : : 1 : 1. Protomerite broadly rounded in front, widest through middle, twice as wide as high, and deeply constricted at septum. Deutomerite slightly broader than high, barrel shaped, widest through middle. Very broadly rounded or flat- tened at posterior end. Satellite longer than primite in all associations observed. Nucleus not seen. Endocyte very dense, black. Epimerite a short digitiform process equal in length to protomerite of cephalont. Cysts spherical, 560/* in average diameter. Spore ducts 3 to 3.5 mm. in length, four in number, arranged around one pole of cyst. Spores discharged in chains. Cylindrical, 3 by 6.5/*. Taken at Douglas Lake, Mich. Hosts: GeuthopMlus latens Scud- der and C. maculatus (Say). Habitat: Intestine. 108 ILLINOIS BIOLOGICAL MONOGRAPHS [318 GREGARINA CONSOBRINA EUis [Figure 196] 1913 Gregarina consobrina Ellis 1913b :267 Gregarina: Sporonts biassociative, obese. Average length of sporonts 600/*, average width 450/t. Ratio length protomerite : total length primite :: 1 : 3.5 to 1 : 4; width protomerite :• width deuto- merite :: 1 : 1.5. Protomerite hemispherical, no constriction at sep- tum. Deutomerite subspherieal to ovoidal, nearly or quite as wide as long, broadly rounded posteriorly. Endocyte not described. Nucleus not seen. Epimerite short, simple, digitiform. Cysts 250 to 300/* in diameter. Spore ducts 4 to 6, all in one hemis- phere, 900 to 1200/A in length. Spores extruded in chains, cylindrical, 3.2 by Six.. Taken at Boulder, Colo. Host: Ceuthophilus valgas Scudder. Habitat : Intestine. GREGARINA ILLINENSIS Watson [Figure 207] 1915 Gregarina illinensis Watson 1915:34 Host: IscJmoptera pennsylvatiica (de Geer). This species was taken at Urbana, 111., in November, 1914. The intestine of one field cockroach was found to contain twenty-five asso- ciations. A dozen or more immature specimens of the insect were collected at various times throughout the fall but only the one was infected. The sporonts are biassociative and elongate cylindrical in shape. The maximum length of an association seen was lllO/i, length of the primite being 550/*, its width 180/*. Ratio length protomerite : total length primite : : 1 : 5 ; width protomerite : width deutomerite : : 1 : 1.1 to 1 : 1.5. The protomerite of the primite is dome shaped, the width equalling the height. The widest part of the primite is the mid- dle portion. There is a constriction, not very deep, at the septum. The protomerite of the satellite is rectangular in shape, 1.5 times as wide as high and depressed at the anterior end into which concavity the primite fits. The deutomerite is regularly cylindrical, elongate and well rounded at the posterior end. The nucleus is large and spherical, and contains many small chromidia. The endocyte is dense in both 319] STUDIES ON GREGARINES— WATSON 109 protomerite and deutomerite and is black in transmitted light. The nucleus is not visible in vivo. Cephalonts and cysts were not recovered from the host. A table of measurements in which all dimensions are given in microns follows: Total length association 1110 1110 1080 1050 Primite Length protomerite _ 100 100 100 90 Length deutomerite 450 450 440 410 Width protomerite 130 130 110 110 Width deutomerite 170 180 180 170 Total length sporont 550 550 540 500 Ratio length protom. : total length sporont...l :5.5 1 :5.5 1 :5.4 1 :5.5 width protom. : width deutomerite.l :1.3 1 :1.4 1 :1.7 1 :1.5 Satellite Length protomerite 70 130 80 70 Length deutomerite _ 530 430 440 480 Width protomerite 130 130 130 120 Width deutomerite 190 210 170 180 Total length sporont 560 560 520 550 Ratio length protom. : total length sporont... 1 :8 1 :4.3 1 :6.5 1 :8 width protom. : width deutomerite.l :1.5 1 :1.6 1 :1.3 1 :1.5 This species and the Old World Gregarina Mattarum Sieb. of Blatta orientalis are differentiated as follows: G. Mattarum G. illinensis Shape Irregularly cylindrical Very regularly cylin- drical Posterior end satellite Not well rounded, Well rounded always often pointed Sarcocyte Very thick Thin except in proto- merite Shape protomerite of Flattened, wider at But slightly flattened, satellite base than elsewhere as wide at base as at 1.7 times as wide as top, 1.5 times as wide at top, 2.5 times as as high wide as high 110 ILLINOIS BIOLOGICAL MONOGRAPHS [320 In the following characteristics, the two species agree : Ratio length protom. : total length primite _ 1:5 1:5 length protom.: total length satellite — 1:8 1:8 Shape protomerite of primite Hemispherical Hemispherical Nucleus Spherical Spherical On the strength of the shape of the posterior end of the body, the shape of the satellite, and in the regularity in shape of the body there is basis for the creation of a new species, although in one important factor, proportions, the two species agree. There are no measurements stated for the Old World species. Schneider says " elle devient tres-volumineuse " which indicates that the species may be as large as the one here described. The species described by Leidy (1853:239) from Blatta orientalis agrees in size with both species. His drawings indicate an irregularly shaped body and a more or less sharply pointed posterior extremity and the hosts he dissected were probably the intro- duced European cockroach and the gregarine the Old World G. ilat- tarum. Crawley records (1903:44) the species G. ilattarum as "Common in Periplaneta orientalis, P. americana and Ectobia (Blatta) ger- manica. A few specimens of Ischnoptera pennsylvanica, the field cockroach, were examined, but none contained gregarines." These hosts undoubtedly yielded the same parasites which. Leidy also had found at Philadelphia. EUis (1913b :83) says: "This gregarine was found in several specimens of the native roach Ischnop- tera Pennsylvania from the woods near Douglas Lake. - - Although no intro- duced roaches have been collected in the vicinity , this gregarine from native roaches seemes undoubted the typical G. blattarum, agreeing' in spores, cysts and sporonts with that species. The biological question of interest is, of course, the source of infection of these native roaches. It is possible, however, that G. blattarum is established in the native roaches in the new world. both Fren- zel and Magalhaes found the native roaches to be infected with gregarines other than G. blattarum ." In his Syllabus (1913b :265), Ellis gives measurements which coincide fairly well with those recorded above in the table. The maximum length of a sporont he states to be 520/i, while that of the above species is 560/i. He says "Cysts prolate spheroids, average 450x900^ , spore ducts 10 or more, reaching the length of 20011; sporocysts barrel-shaped, 4x8^," 321] STUDIES ON GREGARINES— WATSON 111 Ellis' drawing differs somewhat in shape from that of any specimen seen by the present writer (ratio length protomerite : total length primite in the former 1 : 3.3, in the latter 1 : 5) but this is not suffi- cient to constitute a new species as it is the only difference in the two. It is highly probable that but one species ds involved. Ellis' specimens were taken from Ischnoptera pennsylvanica (de Geer) at Douglas Lake, Mich. Hall (1907) makes the simple statement that Feriplaneta americana contains Gregarina llattarum. I have no reason to doubt its presence. It is to be noted that the terms Blatta orientalis and Feriplaneta o. are used interchangeably by various authors, the name now accepted being Blatta orientalis L. GEEGARINA GALLIVEEI Watson [Figures 205, 275-290] 1915 Gregarina galliveri Watson 1915 :33-34 Host: Gryllus aiireviatiis Serv. This species was taken at Oyster Bay, Long Island, in August, 1914. The parasite lives in the intestine of the host. The species is rare, being seen only three times in a hundred or more crickets opened, sixty-five associations and five cysts being found in a single host, and a dozen or more associations in each of the other two. In the first named, nearly all the associations were engaged in cyst making. The sporonts are biassociative, even to the smallest seen. The maximum length of an association seen was 590/x., the maximum width 180/n. The animals are quite polymorphic but certain generalizations can be made. The protomerite of the primite is always wider than the deutomerite. Measurements indicate that it is but little wider, but the difference seems much greater because the two places of greatest width, those used in the table of measurements, are widely separated. The protomerite is low and broad, either flat or very slightly rounded at the anterior end and from two to four times as wide as high, the average being three. Its widest part is in the middle, where it is ap- proximately one and a half times as wide as the septum. The proto- merite of the satellite is considerably narrower than that of the primite. It is greatly flattened and from two to four times as wide as high. The deutomerite of the primite is constricted a little just below the septum, widening out below the middle where it attains nearly the measured width of the protomerite. In some instances it is nearly cylindrical. The deutomerite of the satellite is irregularly subglobular to broadly 112 ILLINOIS BIOLOGICAL MONOGRAPHS [322 ellipsoidal in shape and is of approximately the same width as the protomerite of the primite. The ratio of length protomerite : total length primite (for twelve associations) remains nearly constant and is approximately the same in the satellite as in the primite, being 1 : 5. The ratio of width protomerite : width deutomerite of primite is ap- proximately 1.5 : 1 ; in the satellite it is 1 : 1.4. The endocyte is very dense in both protomerite and deutomerite, and is brown in color, not black as in so many species. The protomerite granules are much larger than those in the other species seen in the same host. The nucleus is small and spherical. It is not visible in vivo except in young individuals. Upon carefully flattening out the association on the slide, by slight pressure, a large inflated papilla is seen on the anterior end of the satellite, which fits into a corresponding depression in the primite and makes the union firmer. This was well demonstrated in some specimens from a starved host in which the protoplasm of the parasite was pale tan throughout and both the papilla and the nuclei were clearly visible. The trophozoites possess a knob shaped hyaline epimerite. Cysts are 300 to 350/a in diameter*, very dense like the sporonts and deep brown in eolor. In one cricket, all the associations were engaged in cyst making. Two such processes were watched from the incipiency to the completion of the two cysts, and the process took place in less than half an hour. At 11 a. m., five cysts were present on another slide, and at 2 p. m. there were seven. Several of the cysts which when first observed were sporonts, developed to completion with the extrusion of ripe spores. The maximum number of spore ducts seen on a cyst was nine. The ducts are very long. The spores are barrel shaped, 3 by 6/i. It was anticipated that this species was identical with Crawley's Gregarina kingi because of the peculiarly shaped protomerite of that species, but such was found not to be the case; the two species differ in many respects. The following table indicates the chief differences: *The diameter, exclusive of the transparent layer, is so^u, less. 323] STUDIES ON GREG ARINES— WATSON 113 G. Maximum length of association Eatio length protom. : total length sporont...! width protom. : width deutomerite 1 galliveri O. kingi 350/i 5 0.8 Shape protomerite of primite Shape protomerite of satellite Shape deutomerite of primite Shape deutomerite of satellite Nucleus Endocyte Anterior surface of satellite Cysts, diameter Dehiscence Frequency Broad and flat, shape slightly irregular three times as wide as high "Wider than deutome- rite Flattened, four times as wide as high Constricted below sep- tum, dilated below and widest in poste- rior two-thirds Subspherical to broad- ly ovate Spherical, small Very dense, deep brown in both protomerite and deutomerite Provided with a very large, flattened papilla which fits into large depression in primite 350/i Many spore ducts Bare, not more than one cricket in 40 har- boring it 3 1.1 ' ' Saddle shaped, broad and swollen in front, much narrower be- hind" Narrower than deuto- merite "Subspherical to com- pressed", twice as wide as high ' ' Cylindrical, g e n e r- ally broader in front. Outline often irregu- lar" Spherical, small "Not dense" Shows a slightly raised ring, primite fitting into a very shallow saucer on anterior end of satellite 90 to 100^. Single long spore duct "25% of crickets opened contained these parasites in countless numbers" No other allied species has been described from crickets. 114 ILLINOIS BIOLOGICAL MONOGRAPHS [324 Measurements of a few associations in microns are as follows: Total length association 590 Primite : Length protomerite 60 Length deutomerite 230 Width protomerite _ 150 Width deutomerite 130 Total length sporont 290 Ratio length protom. : total length 1:5 width protom. : width deutomerite 1 :1.1 Satellite : Length protomerite 50 Length deutomerite 250 Width protomerite 110 Width deutomerite 150 Total length sporont 300 Eatio length protom. : total length 1 :6 width protom. : width deutomerite 1 :1.3 Diameter cysts 350 with all dimensions expressed 570 540 490 440 70 60 60 40 200 210 210 190 140 170 180 120 140 150 150 100 270 270 270 230 ■ 1:4 1:4.5 1:4.5 1:5.7 1:1 1:1.1 1:1 1:4.1 50 50 40 50 250 220 180 170 130 140 120 90 180 180 170 120 300 270 220 210 1:6 1:5.4 1:5.5 1:4.2 1:1.4 1:1.3 1:1.4 1:1.3 300 350 GRBGARINA STYGIA Watson [Figure 206] •1915 Gregarina stygia Watson 1915 :33 This new species was taken from Geuthophilus stygius (Scudder), hosts found in an unused cistern on Dr. C. B. Davenport's grounds, at Cold Spring Harbor, L. I. The infection was heavy, as many as five hundred parasites heing found in each of several hosts, and each of the twelve examined con- tained a.t least a few parasites. The region of infection is the intestine. The sporonts are biassociative as adults. The longest association measured 360/t. The sporonts are barrel shaped, the maximum length recorded being 180/* and the maximum width 100/*. The protomerite is nearly hemispherical in the primite and is flattened in the satellite. The deutomerite is widest at or in front of the middle portion. The satellite is somewhat more slender than the primite and is of the same length or a little shorter. The endocyte is dark tan in color, not very dense in either deutomerite or protomerite, and the nucleus is easily visible in 325] STUDIES ON GREGARINES— WATSON 115 vivo. The sarcocyte is thicker at the septum and anterior ends of the protomerite than elsewhere, hut is fairly thick throughout. The nu- cleus is small and spherical and contains one or more large karyosomes. Sections show that the cephalont possesses a single knobbed epi- merite, slightly stalked. The sporozoite is spindle-shaped and contains a large nucleus. Several sporozoites were seen in the sectioned intes- tine lying free in the lumen or contiguous to the epithelial wall. Movement is sluggish and of the ordinary two types, gliding and contortion. Cysts average 150/i in diameter. Dehiscence was not seen. This species is not identical with Gregarina longiducta Ellis (1913a :78-82), from CeuthopMlus latens and C. maculatus. Associations of the latter average 800 - 900/x in length, the smallest observed being 465/i long. Large associations of O. stygia are only 350/* in length. Pro- portions vary as well as lengths. The species differs from G. consobrina Ellis (1913:267) in size. Sporonts of the latter species attain a length of 600/t, those of G. stygia not becoming longer than 180/*. Satellite : No other species is recorded from the genus Ceuthophilus. A table of measurements is appended herewith, all dimensions be- ing given in microns : Total length associations 360 330 300 Primite : Length protomerite 30 Length deutomerite 150 Width protomerite 60 Width deutomerite 100 Total length sporont 180 Ratio length protom. : total length 1 :6 width protom. : width deutomerite 1 :1.6 Satellite : Length protomerite 20 Length deutomerite 160 Width protomerite 60 Width deutomerite 80 Total length sporont 180 Ratio length protom.: total length 1:9 width protom. : width deutomerite 1 :1.3 20 30 140 120 40 55 100 80 160 150 1:8 1:5 1:2.5 1:1.5 25 30 145 120 50 70 60 80 170 150 1:7 1:5 1:1.2 1:1.1 116 ILLINOIS BIOLOGICAL MONOGRAPHS [326 GREGAEINA NIGRA Watson [Figures 210, 333, 334, 335] 1915 Gregarina nigra Watson 1915 :33 Hosts: Melanoplus femur-rubrum (deGeer) ; Encoptolophus sordidus (Burm.). This parasite seems to be present only as a secondary one. It never occurs in large numbers but is generally found in the same host as Grega- rina rigida. During the season of 1913, I found the parasite compara- tively frequently, but not over half a dozen Acridiidae yielded the species when collections were made in the fall of 1914. It is easily differentiated from the more commonly found species in both color and shape, especially of the protomerite. It was collected only at Urbana, Illinois. The maximum length of an association found was 1 mm. The ratios of various parts of the body are about the same as for G. rigida. The shape of the body is, however, quite different. The protomerite is shaped like a truncated cone ; it is widest at the base, flattened on the top and square cornered. It is approximately as high as wide at the base ; there is no constriction or only a very slight one at the septum. A slight in- dentation persists at the apex of the protomerite left by the detachment of the knob-like epimerite. The deutomerite is cylindrical, of the same vridth throughout and very little wider than the protomerite. It termi- nates in a broadly rounded extremity. The protomerite of the satellite is often not at aU flattened but is little shorter than that of the primite and of approximately the same shape. The endocyte of the deutomerite is very opaque and dense, being black in transmitted light. The protomerite is somewhat less dense than the deutomerite. The nucleus is not visible in vivo. It is spherical, in diameter about one .third the width of the deutomerite and contains many karyosomes. The epicyte is thick at the anterior end of the protomerite, being thin elsewhere. I have not been able to differentiate the cysts of this species (if pres- ent in my collections) from those of G. rigida. The size would be about the same, judging from the size of the associations. I have never seen an infection in which this species alone was present so have no way of know- ing exactly which species yielded the cysts found when both species are present in an infection. In the instance of every cyst from Acridiidae which I have watched develop, spore ducts grew from small orange col- ored discs on the surface. The spore ducts were always short and the spores doliform. 327] STUDIES ON GREGARINES— WATSON 117 A table of measurements follows in which all dimensions are given in microns : Total length association 990 880 1000 Primite : Length protomerite 140 Length deutomerite 390 "Width protomerite 120 Width deutomerite 150 Total length sporont 530 Ratio length protom. : total length 1 :3.8 width protom. : width deutomerite 1 :1.2 Satellite : Length protomerite 110 Length deutomerite 350 "Width protomerite 110 Width deutomerite 170 Total length sporont 460 Batio length protom. : total length 1 :4.2 width protom. : width deutomerite 1 :1.5 GREGARINA UDEOPSYLLAE nov. spec. [Figures 260, 261] Host: Udeopsylla nigra (Locustidae). Location, Urbana, 111. Three specimens of this rare host were examined and all found to be moderately infected with an hitherto undescribed gregarine. The para- sites lay in inert masses in the mid intestine. The sporonts are biassociative and obese. The maximum observed length for an association was 600/t. The largest primite was 310/* long and 200/i wide. The average ratio of length protomerite : total length sporont was 1 : 5.2, and the ratio of width protomerite : width deutome- rite : : 1 : 5. The sporont is elongate ellipsoidal in shape. The protome- rite of the primite is slightly longer than wide, widest in the central por- tion, and terminates in a small cone. There is a deep constriction at the septum. The deutomerite is widest in the middle, and the satellite termi- nates in a broadly rounded extremity. The protomerite of the satellite is broad and shallow and from two to three times as wide as long. An in- dentation is present in the anterior end of each protomerite of an asso* ciation. 150 150 290 380 130 140 170 180 440 530 1:3 1:3.5 1:1.4 1:1.3 100 90 340 380 120 130 150 160 440 470 1:4.4 1:5.2 1:1.2 1:1.2 118 ILLINOIS BIOLOGICAL MONOGRAPHS [328 The protoplasm is dense, tan in the protomerite and black in the deu- tomerite. The nucleus is spherical and is visible only in young speci- mens. Cysts and the epimerite were not seen. Some of the more important measurements, with all dimensions given in microns, follow : Total length association 600 580 500 Primite : Length protomerite 60 Length deutomerite 250 Width protomerite 100 Width deutomerite 200 Length sporont 310 Eatio length protom. : total length 1 :5.1 width protom. : width deutomerite 1 :2 Satellite : Length protomerite ..■- 40 Length deutomerite 250 Width protomerite 140 Width deutomerite 190 Length sporont 290 Ratio length protom. : total length 1 :7.2 width protom. : width deutomerite 1 :1.3 This species differs from Gregarina longiducta Ellis in length of the sporonts and in shape of the protomerite; and from G. consobrina Ellis in shape and proportions of the protomerite; it differs from G. stygia Watson in size and shape. The hosts from which all these gregarines are taken are various spe- cies of the genus Ceuthophilus, which is closely related to the genus Udeo- psylla. The parasite in question is readily distinguished from the above species by the cone-shaped protomerite of the primite. LBIDYANA EREATICA (Crawley) Watson [Figures 208, 218-56] 1903 Gregarina achetaeaihreviatae Crawley 1903 :45 1907 Stenophora erratica Crawley 1907 :221 1915 Leidyana solitaria Watson 1915:35 Tiosts -.Gryllus ahhreviatus Serv. and G. pennsylvanicus Burm. The parasites were taken at Cold Spring Harbor and Oyster Bay, L. I.,. Haverford, Pa., and at Urbana, Illinois, during the summer and fall of 1914. 50 50 220 200 100 60 130 110 270 250 1:5.4 1:5 1:1.3 1:1.8 50 50 260 200 100 80 120 110 310 250 1:6.2 1:5 1:1.2 1:1.3 329] STUDIES ON GREGARINES— WATSON 119 The intestine is the usual seat of infection, although the pyloric caeca are not infrequently found to contain parasites. The latter are generally present in small or moderate numbers, from 1 to 25 per host, and nearly ever cricket examined at this season was parasitized. Sometimes the number per host runs up to one hundred or more, but this is rare. The parasites are solitary, never associative in the normal sporont life. The maximum recorded length is 500/i, the maximum width 160/^. The ratio of length protomerite to total length for fifteen specimens is 1 :5 to 1 :7. The ratio of width is 1 : 1.3 to 1 : 1.7. The protomerite is slightly wider than high. It is broadly cone-shaped, dilated in the mid- dle and constricted at the septum. The constriction is very conspicu- ous and fairly deep in the adults. There is no papilla at the anterior end. The deutomerite is cylindrical to elongate ellipsoidal, sometimes tapering but always rounded at the end (Figures 218, 221). The endocyte is very dense and black in the deutomerite (in trans- mitted light) and pale tan in the protomerite, the two parts being sharply contrasted. Longitudinal striations are easily discernible with the aid of an intra vitam stain or after crushing the body and releasing the dense endocyte (Figure 243). The nucleus is spherical and contains one or two small karyosomes. It is not visible in the dense adults, but is seen in vivo in the younger sporonts and in the trophozoites. The epimerite is a large simple spherical hyaline knob set upon a short slender stalk (Figures 224, 227). The sarcocyte is very distinctly visible in contrast to the contiguous endocyte. It is thin and of even width throughout. Trophozoites with epimerites are common, both free in the lumen and attached to the cells of the intestine. They are transparent or nearly so. Some individuals are surprisingly large. Cysts average 350/* in over all diameter, the transparent envelope being about 30/t in thickness when the cyst is new. Dehiscence is by spore ducts from one to twelve or more in number. Spores are extruded from the long ducts in chains. The spores are barrel-shaped and meas- ure 3 by 6/i. This species was described by Crawley (1903:45) as Gregarina achetaeaiireviatae Leidy and later as Stenophora erratica. Crawley first considered the species identical with Leidy 's Gregarina achetaeah- breviatae from the same host but later (1907:221) created for it a new species because " — at the anterior tip of the protomerite the ectosarc is often thickened to form a low papilla, within which are traces of a pore." 120 ILLINOIS BIOLOGICAL MONOGRAPHS [330 It is this character which led him to place the gregarine in the genus Stenophora. He adds: "The suggestion is permissible that this form is actually the common Steno- phora julipusilli Leidy, somewhat altered from being in the wrong host ". The suggestion that the species belongs to the family Stenophoridae is excluded when one considers the method of cyst dehiscence, which is that characteristic of the family Gregarinidae rather than that of the Steno- phoridae. The sarcoeyte at the anterior end of the protomerite is often thick- ened and papillate but I have not seen a trace of a pore. A table of measurements follows, all dimensions being given in microns : Length sporont 500 490 470 420 370 290 Length protomerite 80 70 80 60 60 50 Width protomerite 110 90 80 80 80 50 "Width epimerite 30 Width deutomerite 150 150 160 140 130 60 Ratio length protom. : tl. length 1 :6.3 1 :7 1 :6 1 :7 1 :6.1 1 :6 width protom. : width deu. 1 :1.3 1:1.7 1:2 1:1.7 1:1.6 1:1.2 LBIDYANA GRYLLORUM (Cuenot) Watson 1897 Clepsidrina gryllorum 1900 Gregarina macrocephala 1901 Gregarina gryllorum 1916 Leidyana gryllorum Leidyana: Sporonts solitary, never associative, cylindrical. Length 420ya. Ratio length protomerite : total length : : 1 : 5 ; width protomerite : width deutomerite : : 1 : 1.1. Protomerite subspherical, a deep constriction at septum. Deutomerite cylindrical, conical at end. Epimerite globular, nucleus small, spherical. Cysts spherical or ovoi- dal, 190 to 240/x in diameter. Spore ducts 3 to S/x. Spores barrel shaped, l/M in longest axis. Taken in Ardennes and Meurthe-et-Moselle, France. Host: Oryl- lus domesticus (L.). Habitat: Intestine. Labbe placed this species which had been mentioned but not de- scribed by Cuenot as a synonym of Gregarina macrocephala Schn., [Figure 209] Cuenot 1897 :52-54 'm Labbe 1899 :10 Cuenot 1901:594-5 Watson (This paper) 331] STUDIES ON GREGARINES— WATSON 121 which is only known from the cephalont. Cuenot (1901) says regarding the disposition of the species : "Labbe I'a reunit de son propre chef a la G. macrocephala A. Schn. ; or, cette derniere espece est trop mal connue pour qu'il ait quelque a I'identifier a la mieune; le grand epimerite en forme de massue de 'macrocephala' n'est cer- tainment pas pareil a celui de 'gryllorum.' In a footnote he adds : "Schneider ne decrit pas la forme adulte et ne park pas du nombre de spo- reductes des kystes." Therefore the species has an individuality. It is very similar to the species described here under the name Leidyana erratica. Both are soli- tary, size of the two is nearly the same, ratios of various parts not rad- ically different and shape of the deutomerite quite similar. The cysts are slightly smaller than in the latter species, but they dehisce by approxi- mately the same number of spore ducts and the spores are similar. The epimerites of the two species are spherical and large. The nuclei are spherical. The only difference seems to be in the shape of the protome- rite. In all the hundreds of specimens I have seen of L. erratica, none has possessed a protomerite rounded at the anterior end; all have been decidedly conical at the apex. In the present species, the protomerite is broadly rounded — subspherieal — in shape; the constriction at the sep- tum is considerably deeper than in the other species. I have separated the two on the basis of this character alone, deeming it of sufficient im- port to differentiate the species. Both species are parasites of the genus Gryllus, but of different species. The host of the former, Gryllus do- mesticus, flourishes in the old world and is rare in the United States, having formerly been found about old log houses, the former occupants of which undoubtedly introduced it from Europe (Blatchley). The host of Leidyana erratica, Gryllus abbreviatus, is the common field cricket in the United States. The infection is unlikely to have spread from the one host to the other. HYALOSPOEA ROSCOVIANA Schneider For detailed synopsis and discussion of this species, see the chapter on Coleopteran parasites, under the same species name. The host is Petrohius maritimus, but as the genus Petrobius has been described for both Coleoptera and Orthoptera, it is impossible to state finally whether the host was a beetle or an orthopteran, or a thysanuran. 122 ILLINOIS BIOLOGICAL MONOGRAPHS [332 HYALOSPORA AFFINIS Schneider [Figure 200] 1882 Hyalospora affinis Schneider 1882:445-6 1899 Hyalospora affinis Labbe 1899 :14 Hyalospora: Sporonts biassociative, slender and elongate. Length of cephalonts 300/^. Sporont measurements not given. Ratio length pro- tomerite : total length primite :: 1 : 5 (without epimerite). Ratio width protomerite : width deutomerite : : 1 : 1.8. Endocyte yellow. Epimerite a hyaline knob, present on the primite of an association in the figure given (Fig. 201) . Nucleus ellipsoidal, with one or two karyosomes. Cysts spherical or subspherical, yellow in color, 60/* in diameter. Spores 8.7 by 6^. Taken at Roscoff, France. Host: Machilus cylindrica E. Geoff. Habitat : Intestine. Schneider's figure is a paradox. It shows an association, the pri- mite of which is a cephalont, with an epimerite. This condition is al- most unique in the history of gregarines, for it is an unwritten law that only sporonts couple themselves together. I have, however, seen the phenomenon in one instance in the genus Gregarina. GAMOCYSTIS TENAX Schneider [Figure 201] 1875 Gamocystis tenax Schneider 1875:586-7 1899 Oamocystis tenax Labbe 1899:12 1913 Gamocystis tenax Ellis 1913b :271 Gamocystis: Sporonts biassociative, in apposition, head to head; obese. No protomerite in the sporonts. Body ovoidal to subconical, pos- terior extremity rounded, nucleus spherical with one karyosome. En- docyte with large irregular granules. Cysts spherical, sporulation par- tial, spore ducts 15 or more in number, short, extending only into the thick transparent layer of the cyst. Spores elongate cylindrical, rounded at the ends. Taken at Roscoff, France. Hosts : Blattella lapponica (Ectohia lap- ponica (L.) ; Blatta lapponica). Habitat: Intestine. 333] STUDIES ON GREG ARINES— WATSON 123 HIEMOCYSTIS GRYLLOTALPAB (Leger) Labbe [Figure 211] 1892 Eirmocystis gryllotalpae Leger 1892 :112 1899 Hirmocystis gryllotalpae Labb4 1899 :13 Hirmocystis : Sporonts in associations of two or three. Length of sporonts 80 - dO/j,. Protomerite subspherieal. Cysts spherical, 60/* in diameter. Spores elongate ovoidal, 5 by 2.1/*. Taken at Poitou, France. Host: Gryllotalpa gryllotalpa (L.) (G. vulgaris). Habitat: Intestine. Leger and Labbe include here, as a synonym, Gregarina sphaeru- losa Dufour (1837:12), probably on the strength of the fact that the latter was found in the same host genus. At the end of the chapter on Orthoptera will be found a statement that Dufour 's G. sphaerulosa was described from cysts instead of from sporonts. Dufour did not know the mode of reproduction of the little animals he had discovered a few years previous and looked upon the white spherules as a new species. It is interesting to note that he dis- covered cysts from two unallied hosts and he found enough difference between the cysts to designate them as two separate species. PILEOCBPHALUS BLABBRAB (Frenzel) Labbe [Figures 202, 203] 1892 Gregarina blaierae Frenzel 1892:300-1 1899 PUeocephalus ilaherae Labbe 1899 :20 1913 Gregarina hlaherae BUis 1913b :266 Pileocephalus : Sporonts solitary, rather stout-bodied. Length of sporonts 500/i, width 150/t. Eatio length protomerite : total length spo- ront :: 1 : 5; width protomerite : width deutomerite : 1 1.6. Proto- merite hemispherical to subglobular, 1.4 times as wide as high, very deeply constricted at septum. Deutomerite ovoidal, widest through cen- tral portion or just in front thereof, rounded at posterior end. Nucleus spherical, with one karyosome. Bpimerite long, cordiform, dilated at base into a flattened sphere which is over half the width of the proto- merite in its width. Bpimerite equal in length to half the whole cephalont length (without the epimerite). Cyst and spores not known. Taken at Cordoba, Argentina. Hosts: Blalera claraziana Sauss. and related species. Habitat : Intestine. Leidy 1853:239 Leidy 1856 :47 Diesing 1859 :730 Crawley 1903 :54 Crawley 1907 :226 Ellis 1913b :278 Watson (This paper) 124 ILLINOIS BIOLOGICAL MONOGRAPHS [334 Ellis replaced this species in the genus Gregarina although the only known diagnostic character, the epimerite, does not coincide with that of the genus. This structure does, however, agree in shape with that of the genus Pileocephalus according to Schneider (1875:591) and Labbe (1899:19): "iSpimerite regulier simple conoide ou en fer de lance" and I have replaced it in the genus Pileocephalus. ACTINOCEPHALUS FIMBRIATUS (Diesing) Watson [Figures 189, 190] 1853 Gregarina Locustae Carolinae 1856 Gregarina Locustae carolinae 1859 Gregarina fimbriata 1903 Stephanophora locustaecarolinae 1907 Stephanophora pachyderma 1913 Actinocephalus pachydermus 1916 Actinocephalus fimhriatus Actinocephalus: Sporonts solitary, obovate. Maximum length of sporonts 500/^. Protomerite hemispherical, not constricted at septum but contour continuous with that of deutomerite. Latter tapers slightly, ending in a blunt point. Sarcocyte very thick, especially over anterior end of protomerite. Endoeyte black in deutomerite, less dense in proto- merite. Nucleus spherical with 12 or more small karyosomes. Epimerite an inverted campanula, sessile, with ten or more slender digitiform pro- cesses directed upward along the periphery. Cysts and spores unknown. Taken at Wyncote, Pa. Host: Dissosteira Carolina (L.) : Habitat: Intestine. A cephalont of this species was first seen by Leidy in 1853. He described it and the sporonts of Gregarina locustae carolinae together under the latter name. In 1903, Crawley renamed the species Stephanophora locustaecaroli- nae from the character of the epimerite, as drawn by Leidy. Crawlej' did not see the species then. The error of inclusion was discovered by Crawley from new material in 1907, and he then separated the two spe- cies, describing each in detail. The former he called Stephanophora pachyderma, the latter by the original name. The first binomial name given to this species, however, was Gregarina fimiriata, which Diesing used. He redescribed Gregarina locustae caro- linae of Leidy under a new name adding no new material. He says of this species "proboscis digitato-fribriato", which definitely places his description. 335] STUDIES ON GREGARINES— WATSON 125 Ellis transferred the species in question to the genus Actinoceph- alus, where it belongs because of the character of the epimerite. The genus Stephanophora was distinguished by its flat cushion-like epime- rite with stout broad digits rising from the periphery. The genus has now been merged with another and the name discontinued. INDETERMINATE SPECIES GREGAEINA CONICA Dufour [Figure 102] 1837 Gregarina conica Dufour 1837 :12 1851 Gregarina conica Diesing 1851 :8 1863 Gregarina conica Lankester 1863 :95 Dufour 's description is as follows: "Oblongo-conica ; cephalothorace suWgloboso abdominis tertiam partem adae- quante. Hab. Coleopterorum et Gryllorum." In 1826 Dufour described an intestinal parasite from Coleoptera. In 1828 he named it Conica ; in 1837 he gave as hosts the above animals and named the parasite Gregarina conica. The parasite is illustrated in his 1837 paper. That he had two species under consideration is obvious from his drawings as seen in Figures 101 and 102, one being labelled as from Coleoptera and the other from Gryllus. The former has a crenu- late, stalked epimerite, the latter a simple spherical stalked one. The former figure has been homologized with several drawings by subsequent writers and represented the parasite described in the chapter on Coleop- teran parasites under the name of Actinocephalus conicus (Dufour) Stein. Stein described a parasite, Actinocephalus lucani, from a beetle, which is identical with Dufour 's drawing 7. He did not know of Du- four 's paper and the previous discovery of the species, but Frantzius (1848:195) did, and mentioned Stein's Actinocephalus lucani from Lu- canus, leaving the original Gregarina conica Dufour from Gryllus only. Diesing (1851) listed both G. conica Dufour from Coleoptera and Gryllus, and G. Lucani Stein from Lucanus parallelopi/pedus. Lankester did likewise. After his citation, G. conica dropped out of the literature. It is obvious that Dufour found a parasite in Orthop- tera, but what it was no one can say. He did not find associations and no one knows whether he saw only the isolated cephalonts with the epi- 126 ILLINOIS BIOLOGICAL MONOGRAPHS [336 merites, which he shows in his drawing, or whether he saw sporonts which were not associative. So the generic position of the species is doubtful. The family de- termination is fairly definite, from the simple spherical epimerite, but the species must be relegated to the group of the indeterminate species. GREGARINA DAVINI Leger and Duboscq [Figure 204] 1899 Gregarina Davini Leger and Duboscq 1899 :xxxviii-xl Gregarina: Sporonts not described, cephalonts alone known. Nu- cleus spherical, with a large irregularly shaped karyosome. Epimerite large and spherical, set upon a rather long stout collar formed by a pro- jection of the anterior end of the protomerite. Cysts spherical, with 12 or more long spore ducts from which spores are extruded in chains. Spores barrel shaped, 8/t long. Taken at Marseilles, France. Host: Gryllomorpha dalmatina Ocsk. Habitat: Intestine and caecum. Although sporonts have not been found, the species is undoubtedly a member of the genus Gregarina from the mode of dehiscence and the shape of the epimerite. It cannot be determined whether or not the species has been described elsewhere from the sporont in addition to these other factors under a different name. Until sporonts are found and correlated with the description herewith, the species must remain incomplete. MISCELLANEOUS GREGARINA SPHAERULOSA Dufour [Figure 179] 1837 Gregarina sphaerulosa Dufour 1837 :12 1851 Gregarina sphaerulosa Diesing 1851 :11 1863 Gregarina sphaerulosa Lankester 1863 :94 1899 Hirmocystis gryllotalpae Labbe 1899 :13 Dufour described this form as follows : "Subspherica alba, cephalothorace abdomen adaequanta. Hab. in ventriculo Oedipodarum et Gryllotalpae. EUe-est egalant a peine la grosseur d'une tete de fine epingle a insectes ; . Les individus bien adultes semblent resulter de I'union de deux hemispheres. Des yeux peu rigoreux pourraient croire que ce sont deux individus accouples bout a bout." It is obvious from the description and from the figure that what Dufour 337] STUDIES ON GREGARINES— WATSON 127 saw and named were not sporonts but cysts formed by the union of two equal or sub-equal sporonts. None of his other descriptions of spo- ronts applies to the particular species of Orthoptera from which these cysts were taken, so no sporonts, but only cysts, must have been present in the host. Dufour did not, as might have been the case, describe the cysts and sporonts in the same host as separate species. These cysts were taken from Oedipoda coerulescens and from Gryllotalpa sp. Neither Frantzius nor Lankester mentioned the 'species' and the host. Labbe mentioned it as a synonym of Hirmocystis gryllotalpae (Leger) Labbe, probably from an identity of host genera and certainly not because of any similarity in appearance. GREGARINA SOROR Dufour 1837 :12 1851 :11 1863 :94 1899:34 Just as in the instance above, Dufour has here described cysts in- stead of sporonts. His words are as follows : "Subsphericum alba, cephalothorace abdominis dimidiam partem adaequante." "Celle-ci n'est peut-etre qu'une variete de la precedente; mais le cephalotho- race ne forme pas, comme dans cetta derniere, la moite de tout le corps." The cyst in question consists of two unequal parts, making the "cephalothora" less than half the sphere. Diesing and Lankester mention the form and Labbe places it in his "Uncertain" group under the original name. [Figure 180] 1837 Gregarina soror Dufour 1851 Gregarina soror Diesing 1863 Gregarina soror Lankester 1899 Gregarina soror Labbe 128 ILLINOIS BIOLOGICAL MONOGRAPHS [338 POLYGISTID GREGARINES IN THE COLEOPTERA* NAME OF PAEASITE NAME OF HOST DIDYMOPHTIDAE Bidym&phyes gigantea Stein Bidymophyes paradoxa Stein Didymophyes leuckarti Marshall Oryctes sp. larva. Oryctes nasicornis (L.) larva. Phyllognathus sp. larva. Geotrupes stercorarius (L.) Aphodius prodromiis (Brahm.) Aphodius nitidulus F. Didymophyes minuta (Ishii) Watson Tribolium ferrugineum F. ACTINOCEPHALIDAE Actinocephalus concius (Dufour) Frantzius Dorcus parallelopipedus (L.) Actinocephalus dytiscorum (Frantzius) Watson Dytiscus marginalis L. larva. Actinocephalus stelliformis Sehneider Ocypus olens Mull. larv. and ad. Carabus auratus L. C. violaceus L. Bhizotrogus sp. larva. Chlaenius vestitus (Payk.) Silpha laevigata F. Galerita hicolor Drury Harpalus caliginosus Fab. Actinocephalus digitatus Schneider Actinocephalus acutispora Leger Actinocephalus americanus Crawley Actinocephalus harpali (Crawley) Actinocephalus dicaeli (Crawley) Eliis Actinocephalus crassus (Ellis) Actinocephalus zophus (Ellis) Dicaelus ovalis Leptochirus edax Sharp Nyctobates harbata Knoch Alobates pennsylvanica deGeer Actinocephalus gimbeli (Ellis) Watson Harpalus pennsylvanicus Dej. Asterophora philica (Leidy) Crawley Nyctobates pennsylvanica de- Gefer Asterophora cratoparis Crawley Beloides firmus (Leger) Labbe Beloides tenuis (Leger) Labbe Bothriopsis histrio Schneider Cratoparis lunatus Fab. Dermestes lardarius L. larva Dermestes undulatus Brahm. larva Colymbetes fuscus L. Hydaticus cinereus L. larva Acilius sulcatus L. Dytiscus sp. larva *The species are arranged in families, the families include genera in alpha- betical order, and under each genus the species are placed in chronological sequence. 339] STUDIES ON GREGARINES— WATSON 129 Bothriopsis terpsichorella (Ellis) Wat- son Legeria agilis (Schneider) Labbe Phialoides ornata (Leger) Labbe PUeocephalus iergi (Frenzel) Labb6 Pyxinia rubecula Hammersclimidt Pyxinia crystalligera Frenzel Pyxinia frenzeli Laveran and Mesnil Pyxinia mobuszi Leger and Duboscq Stictospora provincialis Leger Steinina ovalis (Stein) Leger and Du- boscq' Steinina obconica Ishii Steinina rotunda "Watson Steinina harpali "Watson Hydrophilus sp. Colymbetes sp. larva Hydrophilus piceus (L.) larva Necroiia ruficollis Fabr. Dermestes lardarius L. larva D. vulpinus F. adult Dermestes vulpinus Fabr. larva D. peruvianus Casteln. larva, ad. Attagenus pellio L. Anthrenus verhasci Olivier, larva Melolontha sp. larva Rhizotrogus sp. larva Stylocystis ensifera (Ellis) Teneirio molitor L. larva Tribolium ferrugineum F. Amara angustata Say Harpalus pennsylvanicus or (Kirby) Leptochirus edax Sharp longi- STYLOCEPHALIDAE Cystocephalus algerianus Schneider Lophocephalus insignis (Schneider) Labbe Oocephalus hispanus Schneider Stylocephalus oilongatus (Hammer- schmidt) "Watson Stylocephalus longicollis (Stein) "Wat- son Stylocephalus hrevirostris (Kolliker) "Watson Stylocephalus gladiator (Blanchard) "Watson Stylocephalus giganteus EUis Sphaerorhynchus ophioides (Schneider) Labbe Pimelia sp. Helops striatus Geoff. Morica sp. Opatrum sahulosum (L.) Asida grisea (F.) Blaps mortisaga L. Hydrophilus sp. larva Helenophorus collaris L. Eleodes sp. Asida sp. Asida opaca Say Eusattus sp. sp. 130 ILLINOIS BIOLOGICAL MONOGRAPHS [340 ACANTHOSPOEIDAB Acanthospora pileata Leger Acanthospora polymorpha Leger Ancyrophora gracilis Leger Ancyrophora uncinata Leger Comefoides capitatus (Leger) Labbe Comet aides crinitus (Leger) Labbe Corycella armata Leger Omoplus sp. larva Cistelides sp. Hydrous caraboides (L.) larva Carabus sp. larva and ad. Carabus auratus L. Carabus violaceus L. larva and ad. Silpha thoracica L. larva Dytiscus sp. Golymbetes sp. Sericostoma sp, Limnophilus rhombicus (L.) Hydrous sp. larva. Hydrobius sp. larva Gyrinus natator (L.) larva GEEGAEINIDAE Hyalospora roscoviana Schneider Sphaerocystis simplex Leger Euspora fallax Schneider Hirmocystis asidae Leger Hirmocystis harpali "Watson Gregarina cuneata Stein Gregarina polymorpha (Hammer- schmidt) Steia Gregarina amarae Frantzius Gregarina tenuis Hammerschmidt Gregarina elongata Frantzius Gregarina scarabaei Lankester Gregarina passaU Lankester Gregarina melolonthae Lankester Gregarina munieri (Schneider) Labbe Gregarina laucournetensis (Schneider) Labbe Gregarina statirae Frenzel Gregarina longirostris (Leger) Labbe Petrobius maritimus Gyphon pallidulus Boh. Bhizotrogus aestivus Oliv. Asida servillei Sol. Harpalus pennsylvanicus ery- thropus (Dej.) Tenebrio moUtor L. larva and ad. Tenebrio molitor L. larva and ad. Poecilus cupreus (L.) Allecula sp. Crypticus sp. Scarabaeus relictus larva ' Passalus cornutus Fab. Melolontha brunnea Timarcha tenebricosa (F.) Ghrysomela violacea (Goeze) G. haemoptera L. Parnus sp. Statira uwicolor Blanch. Thanasimus formicarius (L.) 341] STUDIES ON GREGARINES— WATSON 131 Gregarina acuta (Leger) Labbe Gregarina steini Berndt Gregarina parva (Crawley) "Watson Gregarina lucani (Crawley) Watson Gregarina cavalierina Blanchard Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina Gregarina socialis Leger guatemalensis Ellis grisea Ellis minuia Ishii katherina Watson iarbarara Watson fragilis Watson tenehrionella Watson gracilis Watson intestinalis Watson monarchia Watson gldbosa Watson platyni Watson Trox perlatus Scriba Teneirio moUtor L. larva Harpalus pennsylvanicus Dej. H. caliginosus Fab. Lucanus dama Thunb. Dendarus tristis Rossi {^coarcticollis Mis.) Eryx ater Fabr. larva Ninus interstitialis Eseh. Tenebrio castaneus Knocb Tribolium ferrugineum F. Coccinella novemnotata Herbst. Coccinella sp. Coccinella sp. Tenebrionidae larva Elateridae larva Pterostichus stygicus Say Pterostichus stygicus Say Coptotomus interrogatus (Fab.) Platynus ruficollis Marsh. XJNCEETAIN SPECIES IN GENUS GREGABINA Gregarina elaterae Crawley Elater sp. larva Gregarina curvata (Frantzius) Diesing Cetonia aurata larva UNCERTAIN SPECIES IN UNCERTAIN FAMILIES Gregarina boletophagi Crawley Gregarina microcephala Leidy Gregarina ovalis (Crawley) Watson Gregarina coptotomi Watson Stylocephalus sp. Gregarina sp. Crawley Boletophagus cornutus Arrhenoplita bicornis Olivier Cucujidae larva Coptotomus interrogatus Fab. Xylopinus saperdioides Oliv. Host not given 132 ILLINOIS BIOLOGICAL MONOGRAPHS [342 DIDYMOPHYBS GIGANTEA Stein [Figures 61, 63] 1848 Didymophyes gigantea Stein 1848 :186 1863 Gregarina gigantea Lankester 1863 :95 1889 Didymophyes gigantea Mingazzini 1889 :234-9 1892 Didymophyes gigantea Leger 1892 :106 Didymophyes: Sporonts biassoeiative, slender, very much attenu- ated. Average length 1 cm., average width 80 to 100/x. Ratio length pro- tomerite : total length primite : : 1 : 30 to 1 : 40 ; width protomerite : width deutomerite : : 1 : 0.66 to 1:1. Protomerite dome shaped with a short wide neck just anterior to septum. Deutomerites two in num- ber, cylindrical, widest at septum and tapering gradually, ending in a blunt rounded extremity.* Septa convex upward. Deutomerites nearly equal in length. Nuclei not visible in vivo and not described. Endo- cyte dense, deeply staining. Epimerite a cylindrical-conical papilla. Cysts spherical, 600 to 700/* in diameter. Spores ovoidal, two in- teguments, 6 by 6.5/t. Taken at Berlin, Naples, and Poitiers. Hosts: Larvae of Oryctes nasicornis (L) ; of PKyllognathus sp. and of Oryctes sp. Habitat: In- testine. DIDYMOPHYBS PAEADOXA Stein [Figures 62, 72] 1848 Didymophyes paradoxa Stein 1848:223 1863 Gregarina paradoxa Lankester 1863:95 1892 Didymophyes rara Leger 1892:106 1899 Didymophyes paradoxa Labbe 1899:8 Didymophyes: Sporonts biassoeiative, short. Length and width not given. Ratio length protomerite : total length : : 1 : 7 to 1:9; width protomerite : width deutomerite : : 1 : 1 to 1.1 : 1. Protomerite dome shaped, considerably flattened, twice as wide as high, a little wider than deutomerite. First deutomerite cylindrical, of same length or V/2 times longer than second ; second tapering to a blunt point. Septa con- *Stein's figure indicates that the first deutomerite in its anterior third is nar- rower than at the first septum, becoming as wide at the septum between the two deutomerites as it is at the septum between protomerite and the first deutomerite. This width is retained throughout the second deutomerite. 343] STUDIES ON GREGARINES— WATSON 133, vex upward. Nuclei visible, spherical and large, one in each deutfl- merite. Cyst and spores unknown. Taken at Berlin and Poitiers. Hosts : Geotrupes sp. and Geotrupes stercoraritis (L.). Habitat: Intestine. DIDYMOPHYES LEUCKAETI Marshall [Figures 59, 60] 1893 Didymophyes leuckarti Marshall 1893:41-2 Didymophyes : Sporonts bi- or tri- associative. Length 280 to. 1120/x. Width not given. Ratio length protomerite : total length : :. 1 : 4 in the association of two ; 1 : 11 in the triple association. Eatio, width protomerite : width deutomerite : : 1 : 1.3 to 1:5. Protomerite dome shaped, broadly rounded, twice as wide as high, constriction at septum. Either 2 or 3 deutomerites, attached one behind the other, each nucleated and separated from others by a straight septum and a conspicuous constriction. Deutomerites barrel shaped, but little wider than protomerite, last one tapering and ending in a more or less broadly rounded extremity. Endocyte dense in both protomerite and deuto- merite. Nuclei spherical, containing many small chromatin bodies. Cysts spherical, one long spore duct. Spores not known. Hosts: Aphodius prodromus (Brahm.) and A. nitidulus F. Habitat : Intestine. The cyst dehiscence as seen by Marshall does not coincide with tha,t reported by Leger. The latter mentions simple rupture ; the former de- hiscence by one long spore duct. If the methods described by both au- thors are to be accepted, various species in the same genus must have different modes of dehiscence. DIDYMOPHYES MINUTA (Ishii) Watson [Figure 71] 1914 Gregarina minuta Ishii 1914:436-7 1916 Didymophyes minuta Watson (This paper) Didymophyes: Sporonts elongate. Length 188/x, width 26/x. Ra- tio length protomerite : total length : : 1 : 23 ; width protomerite : width deutomerite : : 1 : 1.5. Protomerite flattened somewhat, twice as wide as high, deep constriction at septum. Deutomerites cylindrical, about equal in length, constriction between the two, posterior end broadly 134 ILLINOIS BIOLOGICAL MONOGRAPHS [344 rounded. Nuclei spherical, one large karyosome in each. Endoplasm not dense. Cyst and spores unknown. Taken in the Province of Izu, Japan. Host: TriboUum ferrugi- neum F. Habitat: Intestine. Under the name Gregarina minuta, Ishii described and illustrated two species of gregarines, one proving to be the above member of the family Didymophyidae, the other a true Gregarina. The two forms were shown to be different by the absence of a protomerite in the satel- lite in the former and its presence in the latter. There was also a differ- ence in the size of the two kinds of associations. The smaller were those of a true Gregarina, having a protomerite in the satellite, and the name used by the author, Gregarina minuta, applies to them only. The larger associations are those of the other form, and I have called this species Didymophyes minuta (Ishii). For a more detailed argument concern- ing these species, see appendix at the end of this chapter. ACTINOCBPHALUS CONICUS (Dufour) Frantzius [Figures 75, 76, 101, 102, 103] 1826 sp. 1828 - - Conica 1837 Gregarina conica 1848 Actinocephalus Lucani 1848 Actinocephalus Lucanus 1848 Actinocephalus conicus 1851 Gregarina Lucani 1851 Gregarina conica 1863 Gregarina Lucani 1863 Gregarina conica 1892 Stephanophora radiosa 1899 Stephanophora lucani 1913 Actinocephalus lucani Actinocephalus : Sporonts solitary, length 300 to 400/*. "Width not given. Ratio length protomerite : total length : : 1 : 5 (without epime- rite) ; width protomerite : width deutomerite : : 1 : 3. Protomerite nearly globular, carrying at the apex a persisting epimerite, situated upon a thick prominent neck. Epimerite larger than protomerite, con- sisting of hemispherical plateau around the periphery of which is sit- uated a corona of 12 or more large upwardly directed digitiform pro- cesses. Deep constriction at septum. Deutomerite widest above middle, Dufour 1826 :43 Dufour 1828:367 Dufour 1837 :12 Stein 1848 :223 Frantzius 1848:195 Frantzius 1848:195 Diesing 1851 :14 Diesing 1851 :8 Lankester 1863 :95 Lankester 1863 :95 Leger 1892 :127 Labbe 1899:23 Ellis 1913b :277 345] STUDIES ON GREGARINES— WATSON 135 tapering but ending in a blunt, rounded extremity. Nucleus spherical with several karyosomes or a band of chromidial bodies. Endoeyte yel- lowish. Cysts- spherical, 250ju, in diameter. Spores long, cylindrical, biconi- cal at ends, 13.5 by 4.5/x. Taken at Berlin and at Tourraine (France). Host: Dorcus paral- lelopipedus (L.) (Lucanus p. Fabricus). Habitat: Intestine. There was considerable confusion regarding this species more than half a century ago. Dufour (1826:43) said: "Dans le tube alimentaire de divers Coleopteres, notamment du Lucanus par- allelopipedus, de plusieurs Melasomes et de la Timarcha tenebricosa, j'ai trouve attondamment une espece de Vers intestineaux, dont je joins ici le dessin." It is interesting to note that he called the gregarine an intestinal worm. Two years later he added : "L'espece que j'ai dit habiter les entrailles de divers Coleopteres, merite, a cause de sa forme, le nom Conica.'' By this time Dufour was evidently including many species of greg- arines under the same name, not differentiating them from one another. In 1837, he described in detail, covering two pages, a new genus he established to include a half dozen species which he had discovered, and called the genus Gregarina. One of the species enumerated is Gregarina conica and its hosts are given as Coleoptera and GryUus. That at least two species were concerned in this inclusion is indicated by his figures 7 and 7a, PI. I, copied in my figures 101 and 102. The figures are simi- lar in one respect, they are both conical at the posterior ends. The pro- tomerites, however, are very unlike. Figure 101 compares favorably, despite its fanciful epimerite, with Stein's figure 35, PI. IX (1848), my figure 75, from the intestine of the same beetle. These two species are probably the same and the name of the species should thus be Actino- cephalus conicus (Dufour) Frantzius, Dufour having first named the species and Frantzius having placed it properly.* Frantzius (1848) recorded both Actinocephalus conicus Dufour and A. Lucanus Stein and he mentioned as host of the former GryUus, and of the latter Lucanus. Diesing recorded Gregarina conica Dufour from " Coleopterorum et Gryllorum ventriculus (Dufour)" and G. lucani Stein from Lucanus parallelopipedus. Lankester listed both species. Leger (1892) described the species ■as a new one under the name Stephanophora radiosa. His description *Dufour's Figure 7a is placed in the chapter on Orthopteran Parasites, under the heading Indeterminate Species, G. conica Duf. 136 ILLINOIS BIOLOGICAL MONOGRAPHS [346 of the new genus Stephanophora does not differ from Stem's genus Ac- tinocephalus. Leger's words are as follows: "Appareil de fixation — constitute par iin plateau epais borde d'une couronne de tentacules globuleux. Gregarines toujours solitaires, fixees pendant la plus grande partie de leur ex- istence ; . Kystes spheriques dehiscents par simple rupture . Spores cylindro-bi- coniques." Stein's diagnosis of the genus is as follows: Die andre Form des Haftapparates ensteht dadurch, dass sich der Kopf nach vorn in einen kurzen Stiel verengert, der sich in eine flache, runde, am Rande gekerbte, auf dem Stiel senkfecht stehende Schiebe erweitert. [My Fig. 75]. Die vordere, zura Anheften dienende Flache der Schiebe ist in der Mitte in einer, dem Durchmesser des Stiels gleichkommenden Ausdehnung glatt, von diesem glatten Centrum aus aber bis zur Peripherie sehr regelmassig strahlenformig in Falten gelegt. Jede Einfaltungsfurche fallt einer Einkerbung des Seheibenrandes zusam- men. Ich vereinige die mit einem solchem Haftapparat versehenen Formen zu der Gattung Actinocephalus." The two descriptions are thus synonymous and but one species is involved, as well as but one genus, the epimerite being stalked, with digitif orm processes radiating from a flat central plate. In Stein 's draw- ing the processes turn backwards, in Leger's they point directly for- ward, but this is of no import. Labbe saw the error in considering the two species distinct. He united them under the species name given by ^Stein, leaving the species in the genus of Leger, calling the form Stephanophora lucani (Stein). Ellis replaced the species in the genus to which it was assigned by Stein. But, according to priority, and from the exhibition of all the evidence in the case, the species name given by Dufour should stand valid and the species be called Actinocephalus conicus (Dufour) Frantzius. The removal of the species from the genus Stephanophora takes from the genus the type and only species and the genus thus drops out of usage. 347] STUDIES ON GREGARINES— WATSON 137 ACTINOCEPHALUS DYTISCOEUM (Frantzius) Watson [Figure 148] 1848 Sporadina Dytiscorum Frantzius 1848 :195 1851 Gregarina Dytiscorum Diesing 1851 :12 1863 Gregarina Dytiscorum Lankester 1863 :94 1890 Ancyrophcra uncinata Labbe 1899 :28-9 1916 Actinocephalus dytiscorum Watson (This paper) Actinocephalus: Sporonts robust. Ratio length protomerite : total length : : 1 : 7 ; width protomerite : width deutomerite : : 1 -.1. Protomerite broad and low, twice as wide as high, flattened in front. Very slight constriction at septum. Deutomerite at septum same width as protomerite in front in septum, retaining same width throughout anterior half. Posterior half much narrower, tapering to a blunt point. Cysts large, spherical, spores not known. Taken at , Germany. Host: Dytiscus sp. Habitat: Intes- tine. This species is known from the drawings of Frantzius, one being of an adult sporont ( ?) and the other of a cyst. Diesing gives as host Dytiscus marginalis larva. Labbe regards the species as synonymous with Ancyrophora uncinata Leger, from a similarity of the host, Dytiscus. The sporont, however, has no resemblance to that of Leger 's species, and, although the epimerite of the species in question is not known, it seems to have an individuality. ACTINOCEPHALUS STELLIFORMIS Schneider [Figures 67, 69, 73] 1875. Actinocephalus stelliformis Schneider 1875:588-9 1893 Actinocephalus stelliformis Pfeiffer 1893:5-11 Actinocephalus: Dimensions not given. Ratio length protome- rite : total length :: 1 : 4.5 to 1 : 8; width protomerite : width deutomerite :: 1 : 1.4. Protomerite cylindrical, surmounted by a broadly rounded anterior extremity; same width throughout posterior half, width equal to length. Constriction at septum. Epimerite per- sisting, a small globular structure surmounted by a corona of recurved processes, each slender at the base, dilated and bifid at the distal ex- tremity. Deutomerite widest above the middle, tapering to a long, 138 ILLINOIS BIOLOGICAL MONOGRAPHS [348 sharply pointed extremity. Bndoeyte very dense. Nucleus small, spherical. Cyst and spores unknown. Taken at Paris. Hosts: Ocypus olens (Mull.) (Staphylinus o.) larva and adult ; Carabus auratus L. ; Carabus violaceus L. j and Bhizotrogus sp. Iv. Habitat: Intestine. Schneider mentions three varieties of this species: a) body regularly lanceolate, epimerite persistent; b) body subspherical ; e) body ex- tremely elongate. Pfeiffer found the species in Carabus violaceus L. ACTINOCBPHALUS DIGITATUS Schneider [Figure 66] 1875 Actinocephalus digitatus Schneider 1875:590 Actinoeephalus : Sporonts solitary, short, obese. Measurements not given. Ratio length protomerite : total length :: 1 : 4.5. Ratio width protomerite : width deutomerite : : 1 : 1.4. Protomerite dome- shaped, widest in posterior half, width equal to height. Constriction at septum. Deutomerite rather short, widest a short distance below septum and tapering gradually to a sharp point. Nucleus small, spheri- cal. Epimerite persistent, a globular structure surmounted by a rosette of 8 to 10 recurved digitiform processes rounded at their extremities. Cysts and spores unknown. Taken at Paris. Host: Chlaenius vestitus (Payk.). Habitat: Intestine. Schneider says: "L'Actinocephahus Lucanus de Stein, provenant de la larva d'un Lucanus parallelopipedus, est une espece fort voisine de celle-ci." ACTINOCEPHALUS ACUTISPORA Leger [Figures 212, 213] 1892 Actinocephalus acutispora Leger 1892:142 1899 Actinocephalus acutispora Labbe 1899:26 Actinocephalus : Sporonts solitary, length 1000 to 1500/*. Width not given. Ratio length protomerite : total length : : 1 : 11 ; ratio width protomerite : width deutomerite : : 1 : 1.4. Protomerite 1.5 times as long as wide, cylindrical, rounded at the top and slightly dilated in posterior fourth. Constriction at septum. Deutomerite very long and 349] STUDIES ON GREGARINES— WATSON 139 slender, slightly wider than protomerite at shoulder and tapering to a long acutely pointed posterior extremity. Bpimerite a spherical button situated upon a short collar and consisting of 12 slender incurved processes terminating in obtuse points. Endocyte brownish yeUow. Nucleus spherical, containing 3 to 7 karyosomes. Cysts ovoidal, 550 to 600;tt by 280fi. Dehiscence by simple rupture. Spores obese, acutely pointed, two sizes, 4.5 by 2.8fi and 6.4 by 3.6/i. Taken at Poitiers, France. Host: Silpha laevigata F. Habitat: Intestine. ACTINOCEPHALUS AMBEICANUS Crawley [Figure 64] 1903 Actinocephalus americanus Crawley 1903a :636 Actinocephalus : The generic determination of this species is not absolute. Crawley's description is quoted below: "This species is created for a . single individual found in Galerita bicolor Drury. . It is placed in the gen«s Actinocephalus on account of the form of both protomerite and deutomerite, the presence of several karyosomes in the nu- cleus and the fact that the host was a carnivorous Arthropod. The gregarine was 200fji long, 35^ of which represented the length of the protomerite, 45^ broad. The epicyte — showed a little papilla at the anterior tip of the protomerite. — The en- docyte was much denser in the deutomerite than in the protomerite. ." It is probable that Crawley's determination is correct but the recovery of cysts and spores as well as the epimerite is needed to substantiate the determination. ACTINOCEPHALUS HAEPALI (Crawley) [Figure 70] 1903 Gregarina harpaU Crawley 1903:49 1903 Actinocephalus harpali Crawley 1903a :637-8 Actinocephalus: Sporonts solitary, obese. Length 225 to 1200^. Width not given. Eatio length protomerite : total length : : 1 : 6.5 ; width protomerite : width deutomerite : : 1 : 1.2. Protomerite broadly dome-shaped, twice as wide as high, flattened at the free end, deeply constricted at the septum. Deutomerite widest a short distance below septum where it is but little wider than the protomerite, tapering from anterior fourth to a blunt posterior end. Endocyte very dense, blackish. 140 ILLINOIS BIOLOGICAL MONOGRAPHS [350 of equal density in protomerite and deutomerite. Nucleus large, spheri- cal, containing several karyosomes. Cysts spherical, 640/a in diameter, dehiscing by simple rupture. Spores 9 by 7.5/*, diamond shaped. Taken at Wyncote, Pa. Host: Harpalus caliginosus Fab. Habi- tat : Intestine. "These gregarines were present in the intestine of the one beetle examined in hundreds." ACTINOCBPHALUS DICAELI (Crawley) Watson [Figure 100] 1903 Gregarina discaeli Crawley 1903 :47 1903 Gregarina dicaeli Crawley 1903a :641 1913 Actmocephalus discaeli Ellis 1913b :279 1916 Actinocephalus dicaeli Watson (This paper) Actinocephalus : Sporonts solitary, greatly elongate. Length 1200/t. Ratio length protomerite : total length : : 1 : 15 ; width pro- tomerite : width deutomerite : : 1 : 1.2. Protomerite pentagonal, seen in lateral optical section, widest through middle, flattened on top, width about equal to height. Slight constriction at septum. Deutomerite very elongate, cylindrical, slightly tapering to a blunt point. Epimerite not known. Endocyte dense, opaque in deutomerite, nearly transparent in protomerite. Nucleus spherical, with several karyosomes. Cyst and spores not known. Taken in Pennsylvania. Host : Bicaelus ovalis Lee. Habitat : Intes- tine. Crawley placed this species in the genus Gregarina, with a question. In his later paper (1903a) he left it in the same genus but in a list of eight doubtful species. "This gregarine is placed in the genus Actinocephalus because of the general shape of the sporont and the coleopteran host; it was removed from the genus Gregarina because the sporonts do not form associations." Its generic position is still doubtful and from the data at hand might belong to any of these families : Actinocephalidae, Stylocephali- dae or Acanthocephalidae. The generic name of the host and the specific name of the parasite were both misspelled by Crawley in his original paper. This error was corrected in his second memoir ; but Ellis copied the original error, over- looking Crawley's careful explanation of the misprint. 351] STUDIES ON GREG ARINES— WATSON 141 ACTINOCBPHALUS CEASSUS (Ellis) [Figure 68] 1912 Stephanophora crassa Ellis 1912a :688-9 1913 Actinocephalus crassus Ellis 1913b :278 Actinocephalus : Sporonts solitary, obese. Length 50 to 60/x; width not given. Ratio length protomerite : total length : : 1 : 8.3 to 1 : 3.5. Width protomerite : width deutomerite : : 1 : 1 to 1 : 5. Protomerite dome shaped, a little wider than high, constricted at septum. Deuto- merite widest in anterior third, where it is a little wider than the protomerite, narrowing abruptly to a rather sharply pointed posterior extremity. Nucleus small, spherical. Cyst and spores not known. Taken at Quirigua, Guatemala. Host: Leptochvrus edax Sharp. Habitat: Intestine. The determination of the species above is not absolute. Since generic diagnoses depend on the character of the epimerite and the spores as weU as on other factors, the absence of these factors tends to make the determination indeterminate. By elimination of negative factors, however, the generic determination is probably correct. ACTINOCEPHALUS ZOPHUS (Ellis) [Figure 74] Ellis 1913a :201-2 Ellis 1913b :278 1913 Stephanophora zopha 1913 Actinocephalus zophus Actinocephalus ; Sporonts elongate, length 1200 to 1600/t. Width not given. Ratio length protomerite : total length : : 1 : 8 to 1 : 13 ; width protomerite : width deutomerite : : 1 : 1.7. Protomerite glo- bose, rounded in front. Constriction at septum. Width same as length. Deutomerite slender, elongate. Widest at shoulder, cylindrical, taper- ing at posterior end to a sharp point. Epimerite persistent, constriction at base and terminating in a corona of 9 or more small regular, rounded, digitiform processes. Bndocyte brown, nucleus not seen. Cyst and spores not known. Taken at New Orleans, La., and at East Falls Church, Va. Hosts: Nyctobates harhata Kjioch (N. barbarata Kn.) ; Nyctobates pennsyl- vanica deGeer. Habitat : Intestine. This species was described by EUis as belonging to the genus 142 ILLINOIS BIOLOGICAL MONOGRAPHS [352 Stephanophora ; an error he afterwards corrected and placed the species in the present genus. Ellis mentions the fact that the record of a species found by Craw- ley among Leidy's manuscripts seems to indicate that the latter is the same species as that which he describes as A. zophus. His words are as follows : "Figs. 29 and 30 (Crawley 1903, PI. Ill), as taken from Leidy's Mss. are of different Gregarines, a fact recognized by Crawley. Fig. 30 represents a grega- rine closely related to G. grisea, while Fig. 29 is apparently of a sporont of 5". zopha." A comparison of S. zopha (Fig. 74 of this paper) and of Leidy's draw- ing (Fig. 65 of this paper) will indicate that there is a difference in the shape of the sporonts. The protomerite of Leidy's species is wider than the deutomerite; in Ellis', narrower. In the former it is flattened, in the latter elongated. The deutomerite in the former tapers from the septum to a long, sharply pointed posterior extremity. In 8. zopha the deutomerite is widest at the shoulder, a little below the septum and is cylindrical for two-thirds of its length, ending in a slightly tapering, bluntly pointed cone. From these facts and because the epimerite of Leidy's species was not seen, I am inclined to think the two species are not identical and that the one in Leidy's drawing should be relegated to the list of indeterminate species. (See list of such species at end of this chapter). ACTINOCEPHALUS GIMBELI (Ellis) Watson [Figures 126, 127] 1913 Stenophora gimbeli Ellis 1913:464 1916 Actinocephalus gimheli Watson (This paper) Actinoeephalus : Sporonts solitary, obese. Length 520/*. Width not given. Ratio length protomerite : total length : : 1 : 5 to 1 : 6. Eatio width protomerite : width deutomerite :: 1 : 2. Protomerite broadly rounded in front, widest in middle portion, twice as wide as high. Conspicuous constriction at septum. Deutomerite ovoidal, widest through middle, tapering and ending in a bluntly pointed posterior extremity. Endocyte very dense, black in deutomerite, lighter in pro- tomerite, but dense in anterior end. Nucleus not seen. Cyst and spores not known. Taken at Vincennes, Indiana. Host: Harpalus pennsylvanicus Dej. Habitat : Intestine. 3S3] STUDIES ON GREGARINES— WATSON 143 Ellis described this species as a Stenophora because of " — the papilla at the anterior end, which results from the expansion of the thin epicyte. Such a process has already been described by the writer (1912:681-6) in another species of this genus, S. cockerellae Ellis, from Guatemala." The shape of the protomerite is very unlike that of the Stenophori- dae, being twice as wide as high, while in this family it is globular or subglobular. The Stenophoridae are confined to the Diplopoda. Al- though no positive factors are present to indicate its position, yet from exclusion of factors, this species would fall under the family Actino- cephalidae. The general shape is not unlike that of Actinocephalus conicus (Dufour) Stein (Figs. 75 and 76). The two most important determinative factors, epimerite and spores, are unknown and so the determination cannot be absolute. ASTEROPHORA PHILICA (Leidy) Crawley [Figures 78, 113] 1889 Gregarina philica 1903 Asterophora philica 1913 Anthorhynchus philicus Asterophora: Sporonts solitary, very elongate. Length 300 to 2000/i. Maximum width 150/x. Ratio length protomerite : total length : : 1 : 10 to 1 : 15 ; width protomerite : width deutomerite : : 1 : 1.3. Protomerite conical, sharply pointed when deprived of epimerite, longer than wide. Constriction at septum not deep. Deutomerite widest at shoulder, tapering from thence to an attenuated, sharply pointed poste- rior extremity. Epimerite a circular, flattened cushion with a fluted periphery, situated upon a short neck at the apex of the protomerite. Endocjrte and nucleus not described. Cyst and spores not known. Taken at Philadelphia, Pa. Host: Nyctoiates pennsylvanica de- Geer (N. pennsylvanicus). Habitat: Intestine. The above description is taken from Leidy (1889). He remarks that " — the epimerite consists of a horizontal circular disc with a round milled border." In a review of Leidy 's Mss., Crawley found three more drawings from the same beetle. Crawley's words concerning his disposition ol the same are as follows : "Asterophora philica Leidy. Gregarina philica Leidy (1889, p. 9, i Fig.) It is impossible to give a description of this species. Figs. 31 and 32 are Leidy 1889:9-10 Crawley 1903 :53 Ellis 1913b :280> 144 ILLINOIS BIOLOGICAL MONOGRAPHS [354 very plainly of the same gregarine, whereas Fig. 33 seems almost certainly to be- long to a different species. Further, the form figured by Leidy in 1889 is not so ■closely like tftat shown by Figs. 31 and 32 as to render it certain that the two are the same. I therefore include the three different forms under the same name, giving only the figures and reference, until such time as sufficient material is obtained to determine accurately what the actual facts may be. The gregarines figured were about 300 microns long." It is evident that the form figured by Leidy (1889; my figure 113) and in his Mss. (my figure 78), are the same species. The proportions •agree, the shapes of the protomerite are very similar, and the epimerite shown on figure 78 coincides with Leidy 's description of the epimerite. Crawley's figure 32 (my figure 104), may or may not be a cepha- lont of the same species, but the figure 33 (my figure 105), is obviously unlike and must be placed among the uncertain species. (See group at «nd of chapter). Ellis placed the species in the genus Anthorhynchus, but the epi- merite, as described by Leidy, coincides with Labbe's description of the ;genus Asterophora (1899 :22) : "fipimerite en forme de bourrelet circulaire 4 cotes saillantes radices en por- tant qu centre un mammelon saillant. Sporadin allongee," ^except that Leidy does not mention the central papilla. The descrip- tion of the genus Anthorhynchus does not fit the case (Labbe 1899:19) : "Epim. en gros bouton cannele." ASTEROPHORA CRATOPARIS Crawley [Figure 77] 1903 Asterophora cratoparis Crawley 1903:54 1913 Anthorhynchus cratoparis Ellis 1913b :279 Asterophora : Length 540/^. Width not given. Ratio length proto- anerite : total length : : 1 : 5 ; vridth protomerite : width deutomerite : : 1 : 1.1. Protomerite nearly reniform with conical projection at apex «pon which rests the epimerite. Protomerite 1.5 times as wide as high. Deep constriction at septum. Deutomerite widest at shoulder, tapering thence and terminating bluntly. Epimerite consisting of a number of ■"ribs projecting from a central knob." Endocyte not described. Nu- cleus spherical, with one karyosome. Cysts and spores unknown. Taken at Swarthmore, Pa. Host : Cratoparis lunatus Fab. Habitat : Intestine. 355] STUDIES ON GREGARINES— WATSON 145 Ellis removed this species from the genus in which it was first placed, and included it among the members of the genus Anthorhynchus. This genus and Asterophora are differentiated by the character of the epimerite and spores. In our present discussion, the latter factor may be omitted since the spores are not known. The epimerite of Anthor- hynchus is a large canaliculated button; that of the Asterophora con- sists of a circular cushion with a central knob and with a fluted, crenu- late periphery. Crawley's species, therefore, coincides with the latter description and should be returned to that genus. BBLOIDES FIRMUS (Leger) Labbe [Figures 116, 214] 1892 Xiphorhynchus firmus Leger 1892 :137-9 1899 Beloides firmus Labbe 1899 :26-7 Beloides: Sporonts solitary, elongate. The adults 80/* in length. Protomerite conical, dilated in center, constriction at septum. Deuto- merite widest at shoulder, tapering to a sharp point. Ratio length pro- tomerite : total length : : 1 :3.8 ; width protomerite : width deutomerite : : 1 : 1.2. Nucleus elongate ellipsoidal, with several karyosomes. Epi- merite a stalked globose papilla with 12 large lateral curved spines and a long rigid central style (80/* long in adults). Cysts spherical, 180-200/1 in diameter, dehiscence by simple rup- ture, biconical, 14.5 by 6/x. Taken at Poitiers, France. Host: Dermestes lardarius L., larva. Habitat : Intestine. BELOIDES TENUIS (Leger) Labbe [Figure 117] ' 1892 Xiphorhynchus tenuis Leger 1892:139 1899 Beloides tenuis Labbe 1899 :26-7 Beloides: Sporonts solitary, elongate. Epimerite a stalked globu- lar papilla, with 12 stiff lateral curved spines surmounted by a long slender sinuous style. Cysts spherical, spores biconical, pointed. Taken at Poitiers, France. Host: Dermestes undulatus Brahm, larva. Habitat : Intestine. Labbe changed the genus name of this and the foregoing species be- cause of priority. 146 ILLINOIS BIOLOGICAL MONOGRAPHS [356 BOTHRIOPSIS HISTRIO Schneider [Figures 79, 81] 1875 Bothriopsis histrio Schneider 1875 :596 1892 Bothriopsis histrio Leger 1892 :136-7 1903 Bothriopsis histrio Crawley 1903 :54-5 Bothriopsis : Sporonts solitary, maximum length 425/u,. Width not given. Ratio length protomerite : total length sporont : : 1 : 1.6. "Width protomerite : width deutomerite : : very variable. Length of protome- rite more than half that of the whole sporont. Septum strongly convex upward into protomerite. Deutomerite stout, spindle shaped, ending in a sharp point. Epimerite a small flattened disc from which project a half dozen long slender filaments. Nucleus ovoidal, generally placed diagonally, containing several karyosomes. Endocyte yellow in young, brownish black in adults. Cysts spherical, 400 to 500/*. Spores obese, biconical, 7.2 by 5/x. Taken at Paris and Tourraine, Prance, and at Wyncote, Pa. Hosts : Hydaticus cinereus, larv. ; Colymietes fuscus; Acilius sulcatus; and Dy- tiscus sp. larv. Habitat: Intestine. Schneider stated that this species is highly polymorphic, and he described two varieties, the type form and a variety marginata, which is more active. He found no epimerite, but this was discovered later by Leger, who described it as consisting of six slender filaments, 80-90/* long. Leger also discovered the spores. Crawley's observations on this species vary somewhat from those of Schneider ; for instance, he says : " the protomerite is a large rounded mass, Wut whereas Schneider's figures represent it to be solid, I find that it contains, at least in some cases, a large cav- ity. Within this cavity was a fluid in which floated a few granules. the sep- tum dips backward. In a number of cases, however, the septum dipped forward, and such appears to be the only condition seen by Schneider. ." Crawley found that in the stained specimens the protomerite is more densely granular than the deutomerite. BOTHRIOPSIS TERPSICHORELLA (Ellis) Watson [Figure 80] 1913 Legeria terpsichorella Ellis 1913b :276 1916 Bothriopsis terpsichorella Watson (This paper) Bothriopsis: Sporonts solitary, average length 720/*. Width 145/i. Ratio length protomerite : total length : : 1 :1 to 1.8 : 1. Ratio width pro- 357] STUDIES ON GREGARINES— WATSON 147 tomerite : width deutomerite : : 1.3 : 1. Protomerite equal to or longer than deutomerite, the anterior fourth hemispherical to subglobose, below which is an elevated flange-like portion, remaining two thirds cylindri- cal. No constriction at septum. Septum projecting forward into pro- tomerite like the finger of a glove. Deutomerite ovoidal, tapering, bluntly pointed posteriorly. Endocyte dense, homogeneous, light brown. Cysts and spores not known. Taken at Douglas Lake, Mich. Host: HydrophUus sp. Habitat: Intestine. This species was described by Ellis as a member of the genus Lege- ria. His description is as follows : "Epimerite not seen ; sporonts extremely active, constantly changing the shape of the anterior three-fifths of the body and proceeding ' rather rapidly in a serpentine path as a result, the protomerite often being bent almost forty-five de- grees from the main axis of the body; expanded individual with a protomerite equal to or longer than the deutomerite, the anterior fourth of the protomerite hemispherical to subglobose, below which is an elevated flange-like portion, re- maining two thirds cylindrical, the posterior portion with a cup-shaped depression some 6o° deep into which the anterior conical portion of the deutomerite fits ; deu- tomerite excepting the portion included by the protomerite ovoid, rather sharply rounded posteriorly; average sporonts 720fi in length; ." A comparison of figure 82, a copy of Legeria agilis (Schn.) Labbe with figure 80, Ellis' species in question, reveals differences in the two. The genus Legeria is characterized by: a) deutomerite spindle shaped ( same as in Bothriopsis) ; b) protomerite much less than half the total length; c) protomerite cylindrical, dilated in anterior third, terminating in a simple obtuse angled cone; d) septum broadly convex upward into the protomerite in the shape of an hemisphere; e) nucleus spherical; f) agil- ity of movement not confined to protomerite, but equally active in both segments. The species in question does not belong in this genus for the protomerite occupies more than half the total length, it does not termi- nate in a cone, the septum is not broadly dome shaped and movement is not equally active throughout the sporont. Bothriopsis is diagnosed by Schneider as having a) an unusually well developed protomerite consisting of a large polymorphic mass con- vex or concave at its anterior end and nearly or equally as long as, or longer than, the deutomerite, cylindrical in posterior two thirds; b) a septum invaginated into the protomerite like the finger of a glove; c) an ellipsoidal nucleus; d) endocyte yellow to dark brown; e) agility o£ movement chiefly confined to the protomerite. The species in question coincides with the genus Bothriopsis in these characteristics: 1) polymorphism chiefiy confined to anterior three 148 ILLINOIS BIOLOGICAL MONOGRAPHS [358. fifths of body; 2) protomerite equal to or longer than deutomerite ; 3) protomerite largest in anterior third, posterior two thirds cylindrical; 4) septum invaginated into protomerite for the posterior third of its length ; 5) endocyte light brown. I have therefore changed the name of the species to Bothriopsis terpsichorella. LEGEEIA AGILIS (Schneider) LabbS [Figure 82] 1875 Dufouria agilis Schneider 1875 :595-6 1899 Legeria agilis Labbe 1899:24 Legeria: Sporonts solitary; measurements not given. Eatio length protomerite : total length ::1 :2.5 to 1 :3. Width protomerite : width deutomerite : : 1.1 : 1. Protomerite irregularly cylindrical, con- siderably dilated in anterior third, terminated by an obtuse angled cone as wide as high. No constriction at septum. Septum convex upward into protomerite. Deutomerite irreguarly cylindrical, tapering from middle to a sharp point. Nucleus spherical, containing several karyo- somes. Cysts spherical, dehiscing by simple rupture. Spores cylindro-bi- Gonical. Taken at Paris. Host: Colymbetes sp. larv. Habitat: Intestine. PHIALOIDES ORNATA (Leger) Labbe [Figures 87, 88] 1892 Phialis ornata Leger 1892 :135 1899 Phialoides ornata Labbe 1899:24 Phialoides: Sporonts solitary, rather obese. Average Idngth 1200/x. Width not given. Ratio length protomerite : total length : : 1 : 3.3 ; width protomerite : width deutomerite : : 1 : 1.2. Protomerite subglobular, as wide as high, constriction at septum. Deutomerite broadly ellipsoidal, widest in middle, broadly rounded behind. Epime- rite persistent, a long slender cylinder, nearly as long as the whole spo- ront (exclusive of the epimerite), terminating in a dome shaped retrac- tile structure surrounded by a thickened collar, above which is a ring of fine triangular chitinous teeth. Nucleus spherical, containing several karyosomes. 359] STUDIES ON GREGARINES— WATSON 149 Cysts spherical, 300 to 400/* in diameter, dehiscing by simple rup- ture. Spores biconical, swollen in middle, 10.5 by 6.75/x. Taken at Poitiers, France. Host: HydropMlus piceus (L.) larv. Habitat : Intestine. Labbe included with this species, as a synonym, KoUiker's Greg- arina irevirostra (1848:12), probably because of the similarity in. hosts. KoUiker's species shows a 'proboscis' as does Leger's, but onfr much shorter and differently shaped. The former is a short xiphoid cone, only half the length of the protomerite ; the latter a long cylindri- cal process, three times the length of the protomerite. The latter is re- tractile, but KoUiker does not mention that this is true of his species.. His drawing does not indicate the circular distal collar armed with teeth. I am inclined to think the species are quite distinct, and hav^ therefore placed KoUiker's species in the genus Stylocephalus. For further description, see under the heading Stylocephalus 'brevirosiris (KoUiker). PILEOCEPHALUS BEEGI (Prenzel) Labbe [Figure 83] 1892 Gregarina iergi Frenzel 1892 :286 1899 PUeocephalus Iergi Labbe 1899 :20 PUeocephalus : Sporonts solitary, barrel shaped. Length of larg- est 330jLi, width 90/x. Eatio length protomerite : total length : : 1 : 5.2 ; width protomerite : width deutomerite : : 1 :1.6. Protomerite hemis- pherical, evenly rounded, 1.7 times wider than high, slight constriction at septum. Deutomerite broadly ellipsoidal, wider in middle, broadly rounded, nearly flattened posteriorly. Epimerite a large hyaline cen- trally dilated and sharply pointed cone half the length of the whole= cephalont without the epimerite. Nucleus spherical with one large karyosome. Endocyte dense, gray to black. Cyst and spores unknown. Taken at Cordoba, Argentina. Host: Necrobia ruficollis Fabr. (Corymetes ruf.). Habitat: Intestine. [Figures 119, 159] Hammerschmidt 1838 :357 ',cula Frantzius 1848 :193, Diesing 1851:12 Lankester 1863 :95 Leger 1892:140 Labbe 1899 :26 150 ILLINOIS BIOLOGICAL MONOGRAPHS [360 PYXINIA RUBECULA Hammerschmidt 1838 Pyxinia ruhecula 1848 Actinocephalus rubecula Frantzius 1848:193, 195 1851 Gregarina rubecula 1863 Gregarina ruhecula 1892 Pyxinia ruhecula 1899 Pyxinia ruhecula Pyxinia: Sporonts solitary, obese. Measurements not given. Ra- tio protomerite : total length : : 1 : 3.6. Width protomerite : width deu- tomerite : : 1 : 1.2. Protomerite large, regularly eonoidal, a little longer than wide (1.2 :1), constriction at septum. Deutomerite conical, wid- est at shoulder, tapering to a slender, pointed extremity. Endocyte dense, of protomerite much less dense. Nucleus ellipsoidal.* Epimerite situated upon a short neck, urn-shaped, wide mouthed, crenulate on the periphery, with a short, stout conical style projecting upward through the center. Cysts spherical, 250 to 280/t in diameter, spores bluntly biconical, 14 by?;,*. Taken at ?, Germany, and at Poitiers, France. Hosts: Dermestes lardarius L. larva and D. vulpinus Fabr. adult. PYXINIA CRYSTALLIGERA Frenzel [Figures 84, 85, 86] 1892 Pyxinia crystalligera Frenzel 1892 :314-29 Pyxinia: Sporonts solitary, elongate. Maximum length 750/t. "Width not given. Ratio length protomerite : total length : : 1 : 5 to 1 : 10 ; width protomerite : width deutomerite : : 1.1 : 1. Protomerite spher- ical in adults. Deutomerite of adults regularly cylindrical, tapering in posterior third to a long, slender, bluntly pointed extremity. Epime- rite a short sharp rigid style resting upon a small crenulate corona, the whole superimposed upon the cone shaped protomerite of the cephalont. Endocyte containing large, strongly refractile variously shaped crystals and granules of pyxinin. Nucleus irregularly ellipsoidal, containing several karyosomes. Cyst and spores not known. Taken at Cordoba, Argentina. Hosts : Dermestes vulpinus Fabr. ; Dermestes peruvianus Casteln., adults and larvae of both. Habitat: Intestine. ♦Frantzius' illustration shows a spherical nucleus. 361] STUDIES ON GREGARINES— WATSON 151 PYXINIA FRENZELI Laveran and Mesnil [Figure 89] 1900 Pyxinia Frenzeli Laveran and Mesnil 1900 -.554-7 Pyxinia : Sporonts solitary, obese. Length 200/i. Maximum length of cephalonts IbO/i. Maximum width 40/x. Cephalonts only illustrated. Eatio length protomerite : total length : : 1 : 4 ; width protomerite : width deutomerite : : 1 : 2. Protomerite (of cephalonts) cylindrical to subglobose, constricted at septum. Deutomerite subglobose, nearly as wide as long. Epimerite in two parts, a slender cylindrical base equal in length to protomerite, and superimposed upon same, and a short, sharp, apical style equal in length to the cylinder. Nucleus spherical, containing a large karyosome. Cysts not seen ; spores ovoidal, 14 by 6/i. Taken at Paris. Hosts: Attagenus pellio {Dermestes STp.). Habi- tat : Intestine. PYXINIA MOBUSZI Leger and Duboscq [Figures 97, 98] 1900 Pyxinia Mobuszi Leger and Duboscq 1900 :1566 1902 Pyximia Mobuszi Leger and Duboscq 1902 :409-18 Pyxinia : Sporonts solitary. Length 100 to 140;«.. Width not given. Eatio length protomerite : total length : : 1 : 5 to 1 : 6. "Width protome- rite : width deutomerite : : 1 : 1. Protomerite hemispherical, lower margin straight, projecting beyond deutomerite at septum. Deutome- rite regularly cylindrical, ending in a blunt point or in a well rounded extremity. Epimerite persistent, a long slender sinuous style attached to base of the epithelial cell, i. e., to mesothelial wall, of the host, extend- ing through this cell, longitudinally, to lumen, the cephalont body re- maining in lumen, beyond cilia. Epimerite as long or longer than the whole cephalont itself. Endocyte containing paramylin granules and small yellow refractile bodies. Nucleus spherical, with one karyosome and several chromatic granules. Cysts spherical, 60 to 70;it in diameter. Spores elongate, barrel shaped, 6.5 by 7/t long. Taken at Grenoble (?), France. Host: Anthrenus veriasci Olivier, larv. (A. veriasci L.) Habitat: Intestine. Leger 1893 :129-31 Leger 1896 :32 Labbe 1899:21 152 ILLINOIS BIOLOGICAL MONOGRAPHS [362 STICTOSPORA PROVINCIALIS Leger [Figures 90, 91] 1893 Stictospora provincialis 1896 Stictospora provincialis 1899 Stictospora provincialis Stictospora: Sporonts, solitary, elongate: Length 1000 to 2000/i. Width not given. Ratio length protomerite : total length : : 1 : 6. Width protomerite : width deutomerite : : 1 : 1.2. Protomerite subglo- bular, terminating in a broadly conical anterior extremity. Width equal to height. Deep constriction at septum. Deutomerite widest at shoul- der, tapering to a slender, sharply pointed distal portion. Nucleus el- lipsoidal, with several karyosomes, epimerite consists of a short stalked; globular papilla depressed anteriorly, there proceeding from the de- pression a dozen long, baekwardly directed, sharply pointed processes which fit closely around the papilla and completely cover it. Proto- plasm of anterior end of protomerite yellow. Cysts spherical, SOOju in diameter, dehiscence by simple rupture; spores bieonical, slightly curved. Taken near Marseilles, France. Hosts: Larvae of Melolontha sp. and Bhizotrogus sp. Habitat : Intestine. But one species is known in this genus and in the sub-family SticT tosporidae. STEININA OVALIS (Stein) Leger and Duboseq [Figures 92, 93, 94] 1838 Clepsidrina polymorpha 1848 Stylorhynchus ovalis 1848 Stylorhynchus ovalis 1851 Gregarina ovalis 1863 Gregarina polymorpha 1875 Clepsidrina polymorpha 1902 Gregarina polymorpha 1904 Steinina ovalis Leger and Duboseq 1904 :352-5 1910 Steinina ovalis Pfeiffer 1910 :108 Steinina: Sporonts solitary, obese. Length 100/i. Width not given. Ratio length protomerite : total length : : 1 : 2.5 ; width proto- merite : width deutomerite : : 1 : 1.4. Protomerite cylindrical, terminat- Hammerschmidt 1838 :355 Stein 1848:182-223 Frantzius 1848:195 Diesing 1851 :9 Lankester 1863 :95 Schneider 1875:580-2 Berndt 1902 :405 363] STUDIES ON GREG ARINES— WATSON 153 ing in a large cone, as broad as high, no constriction at septum. Deutp- merite short, ovoidal, nearly as wide as long, terminating in an obtuse angled cone. Nucleus spherical and containing one large karyosome. Epimerite a short retractile digitiform process which later becomes a flattened button. Cysts spherical or ovoidal, 100/a in diameter, dehisc- ing by simple rupture. Spores biconical, broad through middle, 9 by 7.5/t. Taken in France. Host : Tenehrio molitor L. larva. Habitat : In- testine. This is a much discussed and confused species. Early writers grouped together all the polycystid gregarines found in the larva of Tenebrio molitor as one species. Hammerschmidt evidently actually found several species for he named the one species he described Clepsid- rina polymorpha. Stein differentiated three species and separated out this one, even assigning to it a different genus than the other two, C. polymorpha and C. cuneata. Schneider described under the name Clepsidrina polymorpha (Hamm.) three species, one of them being the Stylorhynchus ovalis of Stein. His words are as follows : "L'espece Clepsidrina polymorpha a ete instituee par Hammerschmidt, et plus tard demembree par Stein, qui trouva moyen d'etablir a ses depens trois especes dont tine fut reportee dans le genre Stylorhynchus. Ce pretendu S. ovalis est simplement le cephalin de I'une des varietes que nous allons decrire." Berndt, in a long paper on the Gregarines of Tenebrio molitor larva, still considered this species the cephalont of G. polymorpha in 1902. It remained for Leger and Duboscq (1904) to clear up the discus- sion. They created a new genus for this species, and called it Steinina. STEININA OBCONICA Ishii [Figure 95] 1914 Steinina obconica Ishii 1914 :439-41 Steinina: Sporonts solitary, obese. Length 120 to liOfi. "Width 68 - 80fi. Ratio length protomerite : total length : : 1 : 5 to 1 : 7. Width protomerite : width deutomerite : : 1 : 1. Protomerite dome-shaped, three times as wide as high. Septum constricted slightly at periphery. Deu- tomerite widest just below septum, and tapering to a slender, bluntly pointed posterior extremity. Epimerite a short conical hyaline projec- 154 ILLINOIS BIOLOGICAL MONOGRAPHS [364 tion 1/4 as long as the protomerite is Mgh. Endocyte dense. Nucleus spherical. Cysts spherical to slightly ovoidal, 120 by 108/*. Spores unknown. Taken in the Province of Izu, Japan. Host: Tribolium ferrugi- neum F. Habitat: Intestine. The character of the epimerite is evidence that this species is rightly placed. STEININA ROTUNDA Watson [Figure 173] 1915 Steinina rotunda Watson 1915 :32-3 Host : Amara angustata Say. Taken at St. Joseph, 111., November, 1914. Habitat : Intestine. A dozen individuals were found in a single host. The sporonts are solitary, the body stout, short and broad. The epimerite persists even on some of the largest individuals. It is a spherical, sessile or shortly stalked and hyaline knob. The protomerite just below it is broadly coni- cal in shape, widening rapidly downward to form a cylinder bulging in the middle portion. A deep constriction is present at the septum. The protomerite is widest three fourths of its length from the anterior end, and, without the epimerite, it is as high as wide. The deutomerite is practically spherical except in its anterior end, which, at the septum, is more or less flattened or sometimes concave downward. The deutomerite widens rapidly from the septum and is as wide as long. In color, the body is light brown or tan, of equal density in both pro- tomerite and deutomerite ; the protoplasm is homogeneous and not very abundant. The anterior half of the protomerite and the epimerite is transparent. The nucleus is visible in vivo in specimens of all ages. In all the specimens attached to the epithelium, no matter how large, the nucleus contains but one karyosome; in the free individuals, no matter how small, a large number of small deeply staining chromosomes are present. The epicyte is thin and of equal width throughout. Longitudi- nal striations are visible. Most of the specimens seen possessed epimerites, whether free or at- tached. A goodly number of these, however, were free in the lumen. The epimerite disappears by being gradually constricted off. When the specimens are on a slide in a water medium for fifteen minutes, approxi- mately, the epimerite breaks, the supposition being that it is highly por- ous and the sudden strain caused by media of unequal density outside and inside is reduced by the bursting of this fragile structure. When 365] STUDIES ON GREGARINES— WATSON 155 the trophozoite is attached, only the epimerite is embedded and the free ends of several cells are destroyed by the parasite. Very slow movement of progression was noted. The power of con- traction seems to be centered in the anterior part of the deutomerite, for the parasite is able to contract this portion of the body into a narrow neck. This species is very probably a member of the genus Steinina, fam- ily Actinocephalidae, although the cysts and spores are not known. The globular hyaline epimerite corresponds to that of one stage of the epime- rite of the type species, Steinina ovalis, as described by Leger and Du- boscq (1904:352-4). The incipient stylous epimerite and the hat shaped end stage were not observed in this species. The adults are non-associa- tive and in shape of the deutomerite, of the protomerite, and the conoi- dal anterior projection of the protomerite, together with the nuclear shape and content, coincide with those of the type species. Coupling of sporonts takes place probably just previous to cyst formation and not, as in the genus Gregarina, near the beginning of sporont life. Some of the important measurements are given below; all dimen- sions are expressed in microns : Total length sporont 250 220 180 Length protomerite with epimerite 130 105 70 Length epimerite 20 20 - 15 Length protomerite without epimerite 110 85 56 Length deutomerite ,. 120 115 110 Width protomerite 130 90 70 Width deutomerite _ 150 120 85 Ratio length protom. (without epimerite) : total length...l :2.3 1 :2.5 1 -.3.3 width protom.: width deutomerite 1:1.1 1:1.3 1:1.2 Diameter nucleus 40 32 40 STEININA HARPALI nov. spec. [Figures 256-59, 269] Host: Harpalus pennsylvanicus longior (Kirby). Location, Urbana, 111., June, 1915. The parasites were found in the coelom, attached to the intestinal walls of several beetles. The sporonts are solitary, small and obese. The maximum recorded length is 200/^, the average length 150/^, and the max- imum width 100/x. The ratio of length protomerite : total length with- out primite : : 1 : 3 to 1 : 5 and the average ratio of width' protomerite : 1S6 ILLINOIS BIOLOGICAL MONOGRAPHS [366 width deutomerite : : 1 : 1.3. The protomerite is cone-shaped, constricted above the middle, and terminates in almost every instance in a small epi- merite. This structure in youngest individuals is a simple short spike; as the animal grows older it becomes a sphere, and finally becomes cup shaped. Old sporonts sometimes lose this epimerite. The protomerite is widest at the septum and there is here a slight constriction which may, however, be lacking. The deutomerite is ovoidal, widest at the shoulder just below the septum, and terminates in a broadly rounded or slightly tapering posterior end. The nucleus is visible in young individuals as a minute spherical body. The protoplasm is dense in the deutomerite, being black in trans- mitted light; it is nearly as dense in the lower half of the protomerite, but the upper portion of the latter is nearly devoid of endoplasm. The epimerite is clear. Cysts are dense, spherical and average 120/i in outer diameter. The inner diameter is approximately 90j[t. Spores were not seen. Figures for a few individuals measured are as follows; dimensions are given in microns: Total length sporont 200 Length protomerite with epimerite 80 Diameter epimerite _ 20 Length protomerite alone 60 Length deutomerite _ 120 Width protomerite 90 Width deutomerite _ _ 100 Ratio length protom. (without epimerite) : total length..! :3.3 width protom. : width deutomerite 1 :1.1 This species differs from the other species found in the genus Har- palus as follows: Gregarina parva (Crawley) Watson and Hirmocystis harpali Watson are both ass6piative -jAcUnocephalus gvmbeli (Ellis) Watson differs in size and proportions (the epimerite was not seen in the latter species) ; in Actinocephalus harpali (Crawley) the maximum length of the sporonts is 1200m, and in proportions and sizes of cysts (640/x in the latter), the two species are widely different. The species is placed in the genus Steiniaa because the epimerite is a short mobile digitiform process changing through a sphere into a flattened button; the sporonts are small, solitary and obese; the proto- merite terminates in a large cone; the cysts are small. It differs sufficiently in size range from the three other species described in this genus to be designated a separate species. 150 105 65 50 20 18 45 32 85 70 50 105 80 105 1:3.3 1:3.3 1:1.6 1:1 367] STUDIES ON GREG ARINES— WATSON 157 STYLOCYSTIS ENSIFERA (Ellis) [Figures 96, 99] 1912 Stylocephalus ensiferus Ellis 1912a -.686-7 1913 Stylocystis ensiferus Ellis 1913b :274 Stylocystis: Sporonts solitary, short. Average length 40 to 65;m. Ratio length protomerite : total length : : 1 : 3 ; width protomerite : width deutomerite : : 1 : 1 to 1 : 4. Protomerite cylindrical, conical to subglobose. Approximately as wide as high. Deep constriction at sep- tum in adults. Deutomerite half as wide as long, widest at shoulder, tapering slightly and ending in a flattened or very broadly rounded posterior extremity. Bpimerite a stout style, equal to protomerite in length. Endocyte dark gray, opaque. Nucleus not seen. Cyst and spores not known. Taken at Quirigua, Guatemala. Host: Leptochirus edax Sharp. Habitat : Intestine. Ellis first described this species as a member of the family Stylo- cephalus, later removing it to the family Actinocephalidae. CYSTOCEPHALUS ALGERIANUS Schneider [Figures 115, 160] 1886 Cystocephalus algerianus Schneider 1886 :100 1899 Cystocephalus algerianus Labbe 1899 :31 Cystocephalus: Sporonts solitary, ovoidal. Length 3 to 4 mm. Ra- tio length protomerite : total length : : 1 : 6 ; width protomerite : width deutomerite : : 1 : 1.7. Protomerite dome shaped, widest at base, twice as wide as high, no constriction at septum. Deutomerite ovoidal, widest through middle, length less than width, posterior end conical, sharply pointed. Epimerite placed upon a short collar, globose, with conical apex. Nucleus elongate ellipsoidal, containing several karyosomes. Cysts not known. Spores irregularly and peculiarly shaped, 10 by 10.5,1. Taken in Algeria. Host: Pimelia sp. Habitat: Intestine. Schneider 1882 :435 Schneider 1885:14 Labbe 1899:31 158 ILLINOIS BIOLOGICAL MONOGRAPHS [368 LOPHOCEPHALUS INSIGNIS (Schneider) Labbe [Figures 110, 114, 161] 1882 Lophorhynchus insignis 1885 Lophorhynchus insignis 1899 Lophocephalus insignis Lophoeephalus : Sporonts solitary, very elongate. Length 1000/». Width not given. Ratio length protomerite : total length : : 1 : 15 ; width protomerite : width deutomerite : : 1 : 1.3. Protomerite subglo- bose, flattened, twice as wide as high, constriction at septiim. Deutome- rite cylindrical, widest at end of anterior third, flattened at posterior ex- tremity. Nucleus of sporont spherical with one karyosome. Bpimerite a large flattened disc, depressed slightly in center, crenulate on periphery, longitudinally striated and carrying at base a circle of very many short upwardly directed digitiform processes. The cepbalont which possesses the circular disc-shaped epimerite spherical or nearly so. Its nucleus with a coiled chromatin band. Cysts subspherical or subovoidal, 430 by 330/t in diameter, dehiscing by pseudocyst. Spores extruded in chains, irregularly hat-shaped, 10/a long. Taken at Tours, Indre-et-Loire, France. Host: Helops striatus. Habitat : Intestine. OOCEPHALUS HISPANUS Schneider 1886 Oocephalus hispanus Schneider 1886:101 1899 Oocephalus hispanus Labbe 1899:32 Epimerite a sphere carried on a short conical neck. Host: Morica sp. Habitat : Intestine. Ellis (1913b :282) includes this genus with Cystocephalus under the name of the latter. The two genera are, however, distinct, having epi- merites different in shape ; the former being globular, set on a short coni- cal neck, the latter spade-shaped (in side view), i. e. dilated in middle portion and conical at apical end, set on a short cylindrical slender collar. 369] STUDIES ON GREGARINES— WATSON 159 STYLOCBPHALUS OBLONGATUS (Hammerschmidt) Watson [Figures 106, 120] 1838 Bhiziniaohlongata 1848 Sporadina oblongata 1851 Gregarina oblongata 1875 Stylorhynchus oblongatus 1882 Stylorhynchus oblongatus 1916 Stylocephalus oblongatus Hammerschmidt Frantzius Diesing Schneider Schneider Watson 1838 :357 1848 :195 1851 :14 1875 :569 1882 :434 (This paper) Stylocephalus: Sporonts solitary, elongate. Maximum length 3000/t ; width not given. Eatio length protomerite : total length : : 1 : 6 to 1 : 8. Eatio width protomerite : width deutomerite : : 1 : 2. Proto- merite globular, constriction at septum. Deutomerite cylindrical, tap- ering slightly from middle, ending in a rather slender blunt posterior ex- tremity. Epimerite a thick cylindrical neck with a terminal dilated por- tion with papilla on extremity. Wbole epimerite equal to 1.5 to twice the length of protomerite alone. Endocyte yellow in cephalont, becom- ing black in adult sporont. Nucleus ellipsoidal, with several karyo- somes. Cysts irregularly spherical with slight depressions and protuber- ances. Spores brown, united in chains, 7/* in long axis. Taken at Paris and Poitiers, France. Hosts: Opatrum sabulosum (L.) and 4^sida grisea (F.) Habitat: Intestine. Because the name was preoccupied, Ellis renamed the genus Stylo- rhynchus, Stylocephalus. The species thus becomes Stylocephalus ob- longatus. STYLOCEPHALUS LONGICOLLIS (Stein) Watson [Figures 107, 121] 1815 Gregarina sp. 1848 Stylorhynchus longicollis 1848 Stylorhynchus longicollis 1851 Gregarina Mortisagae 1863 Gregarina longicollis 1875 Stylorhynchus longicollis 1882 Stylorhynchus longicollis 1884 Stylorhynchus longicollis 1916 Stylocephalus longicollis Gaede 1815:17 Stein 1848 :222 Frantzius 1848 :195 Diesing 1851 :12 Lankester 1863:95 Schneider 1875:572 Schneider 1882:423 Schneider 1884:1-36 Watson (This paper) Stylocephalus: Sporonts solitary, elongate, given. Eatio length protomerite : total length : : 1 Measurements not 10 ; width protome- 160 ILLINOIS BIOLOGICAL MONOGRAPHS [370 rite : width deutomerite : : 1 : 1.1. Protomerite pentagonal in lateral optical view, truncate at apex, slight constriction at septum, width equal to length. Deutomerite elongate, cylindrical, tapering in posterior two thirds and ending in a rather blunt point. Nucleus ellipsoidal, with sev- eral karyosomes. Endocyte dense. Epimerite consisting of a long slen- der cylindrical neck, terminating in a slightly dilated papillate ante- rior end, the whole three or four times the length of the protomerite alone. Cysts irregularly spherical, surface covered with small indentations and papillae. Spores like those of 8. ohlongatus. Taken at Paris. Host : Blaps mortisaga. Habitat : Intestine. STYLOCEPHALUS BRBVIEOSTKIS (KoUiker) Watson [Figure 118] 1848 Gregarina hrevirostra KoUiker 1848 :12 1848 Stylorhynchus hrevirostris Frantzius 1848 :195 1851 Gregarina brevirostrata Diesing 1851 :9 1863 Gregarina hrevirostris Lankester 1863:95 1899 Phialoides ornata Labb6 1899 :24 1916 Stylocephalus hrevirostris Watson (This paper) Stylocephalus: Sporonts solitary, stout bodied. Ratio length pro- tomerite : total length : : 1 : 4 ; width protomerite : width deutomerite : : 1 : 1.2. Protomerite cylindrical, of nearly equal width throughout, width equal to length, no constriction at septum, corners rounded at an- terior end. Epimerite a small xiphoid conoidal tongue projecting up- ward from center of protomerite, length equal to half that of protome- rite. Deutomerite just below septum a little wider than protomerite, tapering to a rather sharp point. Nucleus spherical, with six to nine small karyosomes. Cyst and spores unknown. Taken at , Germany. Host : Hydrophilus sp. larva. Habitat : Intestine. KoUiker illustrated another figure of this species besides the one copied in figure 118, in which the whole body is less angular in outline (1848, PI. 2, Fig. 15) ; the epimerite is a sphere, the protomerite nearly so also, and the deutomerite ellipsoidal with a well rounded posterior ex- tremity. The animal is drawn under abnormal conditions, however, a drop of egg albumen having been used as a medium and the animal left in it for some time. Frantzius placed this species where it evidently belongs, in the genus Stylocephalus, then called Stylorhynchus. His definition of the genus is "Einzeln lebend mit russelartigem Kopfanhang." 371] STUDIES ON GREG ARINES— WATSON 161 Labbe regarded the species identical with Phialoides ornata, prob- ably because of an identity of hosts rather than a similarity of para- sites. A table of the important characteristics of the two species fol- lows, and speaks for itself. St. hrevirostris Ph. ornata Bpimerite 1/2 length of protome- 3 x length of protomerite rite length 1/8 length of whole spo- Equal to whole sporont ront without epimerite width 1/4 that of protomerite 1/10 that of protomerite shape Xipho-conical, i. e. elon- Cylindrical gate-conoidal, dilated in middle apex Pointed Flattened, a thickened col- lar, thickly set with 20 (more or less) small teeth Protomerite shape Widest at shoulder, taper- Ellipsoidal ing to posterior end where widest Anterior 1/5 Central region Posterior extremityTapering and pointed Broadly rounded Nucleus shape Spherical, several karyo- Spherical, several karyo- somes somes. As noted above, EUis (1912:25) changed the name of the genus from Stylorhynchus to Stylocephalus, hence this name changes also. STYLOCEPHALUS GLADIATOE (Blanchard) Watson 1905 Stylorhynchus gladiator Blanchard 1905:923-8 1916 Stylocephalus gladiator Watson (This paper) Stylocephalus: Sporonts solitary, elongate, average length 300 to 400/t, maximum length 720/x, width 30/^, maximum width 70/i. Protome- rite short, globular. Deutomerite elongate cylindrical, with a slender attenuated posterior extremity, bluntly pointed. Epimerite in two parts, a very long slender cylindrical neck and a dilated xiphoid-shaped apical portion, often longer than the whole gregarine. Nucleus ovoidal with one large karyosome. Cysts not seen. Taken at Grenoble, France. Host : Helenophorus collaris L. Hab- itat : Intestine. 162 ILLINOIS BIOLOGICAL MONOGRAPHS [372 STYLOCBPHALUS GIGANTEUS EUis [Figures 108, 109] 1912 Stylocephalus giganteus Ellis 1912:25-27 Stylocephalus : Sporonts solitary, elongate. Length 1200 to 1800/t. Width not given. Eatio length protomerite : total length : : 1 : 9 to 1 : 18 ; width protomerite : width deutomerite : : 1 : 1 to 1 : 1.5. Proto- merite dome shaped, widest at base or dome shaped, dilated above base, flattened anteriorly. Constriction at septum. Deutomerite widest at shoulder. Cylindrical, terminating in an abrupt but sharply pointed cone. Epimerite a long pointed cone, situated upon a conoidal projec- tion of the protomerite of the cephalont. Endocyte dense. Nucleus not described. Cysts spherical, 450^4 in diameter, entire surface papillated and in- dented, dehiscence by pseudocyst, spores extruded in chains. Spores ir- regularly subspherical, black, 7 by 11/^. Taken at Boulder, and at Denver, Colo. Hosts : Eleodes sp. ; Asida opaca Say; Asida sp. and Eusattus sp. Habitat: Intestine. SPHAERORHYNCHUS OPHIOIDBS (Schneider) Labbe 1886 Sphaerocephalus ophioides Schneider 1886:100 1899 Sphaerorhynchus ophioides Labbe 1899:32 Sphaerorhynchus : Sporonts solitary, elongate. Length 3 to 4 mm. Epimerite 1/6 the total length of cephalont, consisting of a small spheri- cal or ovoidal body carried on a long cylindrical stalk, broadest at base and gradually narrowing toward apical end. Cephalonts 1.3 mm. long, 220j«, of which is length of epimerite and 8.5/* for the terminal sphere. Taken at . Host: Ads sp. Habitat: Intestine. ACANTHOSPORA PILEATA Leger [Figures 162, 215] 1892 Acanthospora pileata Leger 1892:145-6 1899 Acanthospora pileata Labbe 1899 :28 Acanthospora: Sporonts solitary, elongate. Length 300 to 400/i. Ratio length protomerite : total length : : 1 : 6 ; width protomerite : width deutomerite : : 1 : 1.5.- Protomerite nearly hemispherical, little higher than wide, constricted at septum. Deutomerite elongate ellipsoi- 373] STUDIES ON GREGARINES— WATSON 163 dal, widest just anterior to middle. Endocyte brown. Epimerite a broadly conical papiUa. Nucleus ellipsoidal, with several karyosomes. Cysts spherical, 150-180/* in diameter. Spores biconical, ends truncate, with six equatorial spines in a circle. Dimensions 7.5 by 10.5jtt. Taken in the Department of Poitou, France. Hosts : Cistelides sp. ; Omoplus sp. larva (Scudder gives a genus Omophlus, not Omoplus). Habitat : Intestine. ACANTHOSPORA POLYMORPHA Leger [Figure 163] 1896 Acanthospora pol/yniorpha Leger 1899 Acanthospora polymorpha Labbe 1896 :44-46 1899 :28 Acanthospora: Sporonts solitary, elongate, polymorphic. Maxi- mum length lOOOju. Protomerite irregularly cylindro-conical. Deuto- merite ovoidal, widest through middle. Endocyte yellowish brown. Cysts 500 to 700/i in diameter. Spores bipyramidal, each face hex- agonal, each pole armed with 6 short spines and with a circle of 6 equa- torial spines, 8 by 4.4/i. Taken in Poitou and Tourraine, France. Host : Hydrous caraboides (L.) larva. Habitat: Intestine. ANCYROPHORA GRACILIS Leger [Figures 122, 164] 18— Gregarina acus Stein 18—:— 1848 Actinocephalus Acus Prantzius 1848:195 1863 Gregarina acus Lankester 1863 :95 1892 Ancyrophora gracilis Leger 1892:146-7 Ancyrophora: Sporonts solitary, elongate. Maximum length 2000ju; maximum width 400/*. Protomerite conical, dilated in central region. Constriction at septum. Deutomerite widest at shoulder, ta- pering to a long acuminate posterior extremity. Nucleus spherical, with several karyosomes. Epimerite a globular papilla with 8 long back- wardly directed flexible 'tentacles'. Cysts spherical, 200/i in diameter. Spores biconical, truncate, with four spines at each pole and six equatorial spines, 8.5 by 5.1/*. Taken at , Germany, and Poitiers, France. Hosts: Cara- bus sp.; Carabus auratus L. ; C. violaceus L., larvae and adults; and Silpha thoracica L. larva. 164 ILLINOIS BIOLOGICAL MONOGRAPHS [374 This species was first described by Stein under the name Gregarina acus, according to Leger, but no mention is made of the species in Stein's 1848 article. Frantzius and Lankester refer the species to Stein ; Diesing does not mention it. If the originally described species is the same as the species de- scribed by Leger in 1892 under the name Ancyrophora gracilis, then the name of the latter should be changed to A. acus (Stein) Leger. In the absence, however, of complete data, it sta,nds as given by Leger. ANCYEOPHOEA UNCINATA Leger [Figure 216] 1892 Ancyrophora uncinata Leger 1892:147-8 Ancyrophora: Sporonts solitary, length 150 to 200/a. Width not given. Epimerite garnished with 12 rigid hooks in two alternate rows. Cysts spherical. Spores spined, both polar and equatorial, 7.5 by 4.5/x. Taken at Poitiers, France. Hosts: Dytiscus sp. ; Colymietes sp. ; Sericostoma sp. ; and Limnophilus rhombicus (L.) (Phryganea rhomb.). Habitat : Intestine. Labbe placed Gregarina Dytiscorum Frantz. with this species under the name of the latter, evidently from a similarity in the first host given above. The species are, however, unlike and I have separated them, listing the former among Uncertain Species, under the Actinocephalidae. The last three hosts given by Leger are not Coleoptera but Neurop- tera and the circumstance of finding the same species of gregarine in such widely separated hosts is unusual and almost unique, yet the record is authentic. COMBTOIDES CAPITATUS (Leger) Labbe [Figures 123, 124, 165] 1892 Pogonites capitatus Leger 1892:150-1 1899 Cometoides capitatus Labbe 1899:29 Cometoides: Sporonts solitary, elongate. Length 1500/t. Width not given. Eatio length protomerite : total length :: 1 : 13; width protomerite : width deutomerite : : 1 : 1.5. Protomerite subspherical, width equal to height. Constriction at septum. Deutomerite widest at shoulder, tapering from thence to a very long slender bluntly pointed posterior extremity. Epimerite globose, stalked, armed with a sub- 375] STUDIES ON GREGARINES— WATSON 165 ' equatorial band of 12 to 15 long slender flexible filaments 32 to 35/i long. Nucleus spherical, with several karyosomes. Cysts spherical, 300/a in diameter, dehiscence by simple rupture, spores cylindro-biconical, apices truncate, each face octagonal. Poles armed with four spines each, two equatorial rows of spines, spores 2.5 by 5.1/i. Taken at Poitou and Avanton, France. Host: Hydrous sp. larva. Habitat : Intestine. COMETOIDES CRINITUS (Leger) Labbe [Figure 125] 1892 Pogonites crinitus 1899 Cometoides crinitus Leger Labbe 1892:149-50 1899 :29 Cometoides: Sporonts solitary, very elongate. Maximum length 2000/i. Ratio length protomerite : total length : : 1 : 20 ; ratio width protomerite : width deutomerite :: 1 : 1.3. Body shaped very simi- larly to C. capitatus except that it is longer. Epimerite hemispherical, flattened surface upward, armed with an equatorial ring of 6 or 8 long slender flexible filaments 100/t long. Endoplasm brown. Nucleus ellip- soidal, with several karyosomes. Cysts spherical, 200 to 300/* in diameter. Spores cylindro-biconical, spines at the poles and in two equatorial bands. Taken at Poitou and Vendee, France. Host: Hydrobius sp. larva. Habitat: Intestine. CORYCELLA ARMATA Leger [Figures 111, 112, 166] 1892 Corycella armata Leger 1892:144-& Corycella : Sporonts solitary, 280 to 300/t long. Ratio length proto- merite : total length : : 1 : 4 ; width protomerite : width deutome- rite : : 1 : 0.9. Protomerite subglobular, constriction at septum, wider in middle than deutomerite. Deutomerite widest at shoulder, tapering thence to a sharp point. Endoplasm gray brown. Epimerite a large globular papilla set upon a stout cylindrical collar which is two-thirds as long as the protomerite itself, and armed with 8 strong short sharply pointed recurved and backwardly directed hooks. Nucleus spherical, containing several karyosomes. 166 ILLINOIS BIOLOGICAL MONOGRAPHS [376 Cysts spherical, 250/t in diameter. Spores biconical, truncate, 4 small spines at each pole, no equatorial spines. 13 by 6.5/t. Taken at Poitou, France. Host: Qyrmus natator (L.) larva. Habitat : Intestine. HYALOSPORA ROSCOVIANA Schneider [Figure 129] 1875 Hyalospora roscoviana Schneider 1875:584 Hyalospora: Sporonts biassociative, cylindrical, very elongate. Ijength and width not given. Ratio length protomerite : total length primite : : 1 : 9 ; width protomerite : width deutomerite : : 1 : 1.6. Protomerite of primite cylindrical, conical, rounded at anterior extrem- ity, twice as high as wide, a constriction at septum. Deutomerite elon- gate cylindrical, tapering but slightly at posterior end and termina;ting in a rounded extremity. Nucleus elongate ellipsoidal, with one large karyosome. Epimerite not known. Bndocyte yellow to yellow-orange. Cysts spherical (?), dehiscing by simple rupture. Spores broadly ellipsoidal but sharply pointed. Taken at Roscoff, France. Host : Petrobius maritimus. The name Petrobius has been applied to genera of both Orthoptera (Thysanura) (1817) and Coleoptera (1836) and, not knowing which one Schneider found as host, I have included this species among the Ooleopteran as well as among the Orthopteran parasites. Schneider says of the habitat: "Les Petrobius se recontrCnt, en effet, sur le mur meme qui separe le labo- ratoire de la mer, tapis dans les interstices des pierres. La meme espece est commune sur une grande partie du littoral ". Prom its habitat, the host might be either an Orthopteran or a Coleop- teran. This is the only species in the genus Hyalospora. SPHAEROCYSTIS SIMPLEX Leger [Figure 137] 1892 Sphaerocystis simplex Leger 1892:115-^6 Sphaerocystis : Sporonts solitary, subspherical, length 100 to 140/i. Width not given. Dicystid, having protomerite only when young. Shape 377\ STUDIES ON GREGARINES— WATSON 167 sphericsil, with a large papillate extension at each end. Nucleus spheri- cal, with a large karyosome. Cysts spherical, 100/t in diameter, without spore ducts. Eneyst- ment solitary. Spores ovoidal, 10.5 by 7.5/t. Taken at Iteuil (Poitou), France. Host: Cyphon pallidulus Boh. (C. pallidus). Habitat: Intestine. EUSPORA PALLAX Schneider [Figure 131] 1875 Euspora fallax Schneider 1875:583 Euspora: Sporonts biassociativ^^ ellipsoidal. Measurements not given. Ratio length protomerite : total length primite : : 1 : 6 ; width protomerite : width deutomerite :: 1 : 2.5. Protomerite of primite spherical, deep constriction at septum; deutomerite ellipsoidal, widest through middle or just posterior to middle, posterior end flattened. Nucleus spherical with one karyosome. Endoeyte dense except in ante- rior third of protomerite, where there is a distinct conoidal area of less dense endoeyte. Cysts spherical, dehiscing by simple rupture. Spores prismatic, square cornered, pentagonal in optical view. Taken at Roscoff, France. Host : A Melolonthid (Bhizotrogus aes- Asida servUlei Soil. Habitat: Intestine. HIRMOCYSTIS ASIDAE Leger ''" ■'SB 1896 Eirmocystis asidae Leger 1896:30 1899 Hirmocystis asidae Labbe 1899 :13 Hirmoeystis: Sporonts very small, bi- or tri-associative. Cylin- drical. Maximum length of association of two, 20/a. Width not given. Ratio length protomerite : total length primite : : 1 : 10 to 1 : 12 ; width protomerite : width deutomerite : : 1 : 2. Protomerite sub- globular, depressed. Deutomerite elongate cylindrical. Epimerite a small simple hyaline papilla. Myocyte well developed. Nucleus spheri- cal with one small karyosome. Cysts spherical, 70/i, dehiscence by simple rupture. Spores cylin- dro-ovoidal, 6 by 3.5/x. Taken at Ain-Fezza, Tlemcen, Province of Oran, Algeria. Host: Asida servillei Soil. Habitat : Intestine. 168 ILLINOIS BIOLOGICAL MONOGRAPHS [378 HIEMOCYSTIS HARPALI nov. spec. [Figures 265, 266, 267, 268, 273, 274] Host: Harpalus pennsylvanicus erythropus (Dej.). Location Urbana, Illinois, June, 1915. This species was found very abundant in the intestines of four beetles examined, one containing at least a thousand associations. The sporonts were found in linear associations of twos, threes and fours and each sporont is elongate cylindrical in shape. The maximum length of associations found was 1060/u,, maximum length of sporonts 560/t, and maximum width 80/i. Ratio length protomerite : total length : : 1 : 7 ; ratio width protomerite : width deutomerite : : 1 : 1.2. The proto- merite of the primite is dome shaped, a little wider than long and con- stricted at the septum, but not deeply so. The deutomerite is elongate, seven times as long as the protomerite and well rounded at the posterior end. The protomerite of the satellite is very much flattened, twice as wide as high and not deeply constricted at the septum. The primite fits into a very deep concavity in the protomerite of the satellite (See Fig. 274). The protoplasm is very dense, black in the deutomerite and much less dense, and tan in color, in the protomerite. The nucleus is spherical and contains one karyosome visible in adults as a clear spot. The epimerite is large and spherical (Fig. 268). Myonemes are very conspicuous as a horizontal network. Cysts were not seen. A few measurements are as follows, all dimensions being given in microns : Total length of associations 1060 910 730 Primite : Length protomerite _ 80 60 60 Length deutomerite „.... 480 440 300 Width protomerite 70 60 50 Width deutomerite _ _ _ 80 90 60 Total length sporont _.. 560 500 360 Ratio length protom. : total length 1 :7 1 :8.3 1 :6 width protom.: width deutomerite 1:1.1 1:1.5 1:2 Nucleus, diameter 50 379] STUDIES ON GREGARINES— WATSON 169 Satellite : Length protomerite Length deutomerite Width protomerite Width deutomerite „ 50 40 30 450 370 340 90 50 60 80 70 90 500 410 370 140 120 110 150 140 100 140 70 70 130 560 330 280 Total length sporont Batio length protom. : total length 1:10 1:10 1:12 width protom. : width deutomerite.- 1 :9 1 :1.4 1 :1.5 Length associations of more than two sporonts Primite 300 First satellite _ 170 Second satellite 190 Third satellite Total length of association 660 This species is very peculiar in that two distinct types of specimens are encountered, viz. large sporonts 500/* long associated in twos (asso- ciation 1000/* in length), and very small sporonts 100/t long associated in threes and fours. A chain of three of the smaller sporonts seldom exceeds half the length of a chain of two of the larger type. One chain of four small individuals measured only 560/i long. That the two types of sporonts, however, represent a single species is shown by the following facts: (a) one or two of the smaller sporonts are often attached as satellites to a sporont of the larger type; (b) in- termediate sizes are found between the small and the large sporonts; and (c) the small and large sporonts are identical in shape and propor- tions. Since associations are generally composed entirely of one type of individuals, the difference is not a sexual one. This species is very similar in shape and proportions and the deep concavity of the protomerite of the satellite to Gregarina serpentula de Magalhaes, from Gryllus domesticus. The sporonts of the latter occur, however, in twos, while the former occur in threes and fours and it there- fore belongs to a different genus entirely. The species differs considerably from any previously described from the host genus Harpalus. It is differentiated from Gregarina parva (Crawley) Watson, Actinocephalus girnbeli (Ellis) Watson and A. harpali (Crawley) in both measurements and proportions and in the fact that the latter two species are solitary while this one is associative. 170 ILLINOIS BIOLOGICAL MONOGRAPHS [380 GREGARINA CUNEATA Stein [Figures 132, 133, 134, 135, 136, 152] 1838 Clepsidrina polymorpha 1848 Gregarina cuneata 1848 Gregarina cuneata 1851 Gregarina cuneata 1863 Gregarina polymorpha 1875 Clepsidrima polymorpha Tar. cuneata 1899 Gregarina polymorpha var. cuneata 1902 Gregarina cuneata 1903 Gregarina xylopini 1904 Gregarina cuneata 1910 Clepsidrina cuneata 1911 Gregarina cuneata 1914 Gregarina cuneata Hammerschmidt 1838 :357 Stein 1848 :209-10,222 Prantzius 1848 :196 Diesing 1851 :13 Lankester 1863 :95 Schneider 1875:581 Labbe 1899 :11 Berndt 1902 :393-404 Crawley 1903 :47 Leger&Duboseq 1904:354-5 Pfeiffer 1910:108 Ishii 1914:435 Ishii 1914:435 Gregarina: Sporonts biassociative, elongate cylindrical. Length 380/*; width 170/i. Ratio length protomerite : total length primite :: 1:3; width protomerite : width deutomerite primite : : 1 : 1.5. Pro- tomerite elongate cylindrical, 21^ times as wide as posterior portion, dilated at anterior end, widest part acutely angled, apex broadly rounded. Slight constriction at septum. Deutomerite elongate, width gradually increases from septum to posterior portion, terminates in a very broadly rounded extremity. Nucleus spherical, small, with one karyosome. Cysts spherical, 240/u. in diameter, long spore ducts. Spores ex- truded in chains, doliform, 5.7 by 4jii. Taken at Roscoff and Caen, France; Berlin; Philadelphia; and in the province of Izu, Japan. Host : Tenebrio molitor L. larv. an4 adult. Habitat : Intestine. Hammerschmidt described two gregarines from Tenebrio molitor under one name, Clepsidrina polymorpha. He regarded them as differ- ent shapes assumed by the same parasite. Stein said, concerning his discoveries: "Ich fand drei verschiedend Formen, von denen zwei zur Gattung Gregarina in engern Sinne, eine zur Gattung Stylorhynchus gehort. Hammerschmidt kannte wahrscheinlich bereits zwei Formen, doch geht dies selbst aus seinen Abbildungen die gar zu roh sind, nicht mit voUiger Bestimmtheit hervor; er hielt sie aber ftir eine Art und nannte sie Clepsidrina polymorpha.^' Stein's figure is reproduced in Figure 133. 381] STUDIES ON GREGARINES— WATSON 171 Prantzius enumerated among his species both G. polymorpha and O. cuneata Stein, not recognizing that the former included the latter. He did not illustrate the species Gregarina cuneata, but included under the name G. polymorpha one excellent figure of G. cuneata (Fig. 135). Stein said that Frantzius knew all three gregarines in this Tenebrio, but " wirt sie ebenfalls zu einer Art unter dem Namen Gregarina polymorpha zusammen bios aus dem Grunde, weil sie in einem und demselben Thiere leben." He named one of the species Stylorhynchus ovalis. The other two " — sind einander sehr ahnlich und fast gleich gross. Die eine ist durch den nach vorn erweiterten, flach gedruckten, keilahnlichen Kopf, der fast ^ der Lange des Leibes gleichkommt, und durch den nach hinten erweiterten Leib ausgezeich- net; ich nenne sie Gregarina cuneata." Lankester placed this species and Schneider's St. ovalis together as synonyms under the name Gregarina polymorpha Hamm. Schneider grouped together under the name Clepsidrina polymorpha (Hamm.) the three species from Teneirio molitor, which Stein had separated some twenty-five years before. He designated the species which is under dis- cussion as Clepsidrina polymorpha var. cuneata (Stein). He con- sidered adult associations of G. cuneata as young immature associations of G. polymorpha. "Les jeunes individus sent nombreux et remarquables par le volume relatif de leur protomerite (Fig. i6 et 17)." The figure 16 referred to is a typical association of G. cuneata. He says further " — Resemble beaucoup a la precedente ; est arrondie en arriere au deuto- merite et plus massive dans son ensemble (Fig. 11, le primite.)". His figure 11, my figure 132, coincides with Stein's figui^ of his G. cuneata, my figure 133. Berndt studied the gregarines of the larva of Teneirio molitor and isolated G. cuneata from the others. Leger and Duboscq (1904) confirmed his work. (Their drawing is reproduced in my figure 152). In Leidy's unpublished manuscript, Crawley (1903) found two drawings of gregarines taken from the Tenebrionid, Xylopinus saper- dioides. One has been otherwise disposed of, but one drawing is of a spe- cies identical with or very similar to G. cuneata. No description or meas- urements accompanied the drawings. From a similarity of the figures of the type G. cuneata and the figure given by Crawley (my figure 134), the species is the same. Ishii (1911:279 and 1914:435) found the species in Japan (my fig- ure 36) in TriboUum ferrugineum, one of the Tenebrionidae, and very Hammerschmii dt 1838 :357 ? 3tein 1848 :210,222 Frantzius 1848 :193,195 Diesing 1851 :13 Schneider 1875:580 Labbe 1899 :10 Berndt 1902 :404-8 172 ILLINOIS BIOLOGICAL MONOGRAPHS [382 similar to Teneirio molitor. It is quite possible that the parasite is not identical with or a variety of the classic G. cuneata, for the figure does not exactly coincide with the others, but no data whatever accompanies the figures and it seems best to leave the species in the present position. GRBGARINA POLYMORPHA (Hammerschmidt) Stein [Figures 140, 141, 142, 153] 1838 Clepsidrina polymorpha 1848 Gregarina polymorpha 1848 Gregarina polymorpha 1851 Gregarina polymorpha 1875 Clepsidrina polymorpha 1899 Gregarina polymorpha 1902 Gregarina polymorpha 1904 Gregarina polymorpha Leger and Duboscq 1904 :354-7 1910 Clepsidrina polymorpha Pfeiffer 1910 :108 1911 Gregarina polymorpha Ishii 1911 :279 Gregarina: Sporonts biassociative, elongate, cylindrical, maximum length 350/t, maximum width 100/t. Ratio length protomerite : total length : : 1 : 5 to 1 : 7 ; width protomerite : width deutomerite : : 1 : 1.8 to 1 : 2. Protomerite dome shaped, as wide as high, no constric- tion at septum. Deutomerite elongate cylindrical, rounded at posterior extremity. Nucleus small, spherical, one karyosome. Cyst and spores unknown. Taken at Berlin, Germany, and Roseoff and Grenoble, France. Host : Tenehrio molitor L. larva and adult. Habitat : Intestine. Hammerschmidt knew two of the forms of gregarines parasitic in the larvae of Teneirio molitor. He called them, however, by one name. In the words of Stein, "Hammerschmidt kannte wahrscheinlich bereits zwei dieser Formen, ; er hielt sie aber fiir eine Art und nannte sie Clepsidrina polymorpha.'' Stein differentiated the two species, calling one G. cuneata, my fig- ure 133, the other G. polymorpha, my figure 142. Frantzius gave, side by side, figures of Stein's G. cuneata and G. polymorpha, and called them both G. polymorpha. (PI. VII, group V, Figs. 1 and 2; my figures 135 and 140). Lankester mentioned G. polymorpha and under this name gave as synonyms Stylorhynchus ovalis Stein and G. cuneata Stein. Schneider brought together again in coincidence with Hammer- 383] STUDIES ON GREG ARINES— WATSON 173 Schmidt's original determination, the three species which Stein had dif- ferentiated, and added another variety. He described 1) Clepsidrina polymorpha var. cuneata, 2) C. polymorpha typica, 3) C. mimosa, and 4) disposes of Stylorhynchus ovalis Stein as " — simplement le cephalin de Tune des varietes que nous aliens decrire." Of these forms, the first has been designated Gregarina cuneata Stein; the second remains Gregarina polymorpha; the third has been dropped as an authentic species for it is obviously immature and prob- ably from its shape a young individual of G. cuneata; the fourth is now Steinina ovalis (Stein) Leger and Duboscq. Berndt separated the species G. polymorpha from G. cuneata, de- scribing each in detail. Leger and Duboscq corroborated his work and created the genus Steinina for the species previously known as Stylo- rhynchus ovalis Stein. Ishii found the species in Japan, from one of the Tenebrionidae. No description of adults is given. GRBGAEINA AMARAE Frantzius 1838 Clepsidrina ovata Hammerschmidt 1838:356 1848 Gregarina amarae Frantzius 1848:195 1851 Gregarina Amarae Diesing 1851:12 1863 Gregarina Amarae Lankester 1863 :94 1899 Gregarina amarae Labbe 1899 :36 This parasite has not been found since the original discovery of Hammerschmidt. Frantzius mentioned it by name only; Diesing gave this description : "Gregarina Amarae Frantzius. Proboscis Receptaculum ovatum breve. Corpus subglobosum. Longit. 9/40 ' ' ', crassit Clepsidrina ovata Hamm. (Individua bina postice juncta)" . Habitac- ulum Amara cuprea, in intestinus tenuibus (Hamm.)." Labbe says that the host is probably the beetle known now as Poeci- lus cupreus (L.). That this species is a member of the genus Gregarina is attested by Diesing 's words "Individua bina postice juncta" which indicates the biassociative nature of the sporonts. No drawing accompanies any available mention of the species. Frantzius 1848:195 Diesing 1851 -lis Lankester 1863:94 174 ILLINOIS BIOLOGICAL MONOGRAPHS [384 GRBGARINA TENUIS Hammerschmidt 1848 Gregarina tenuis 1851 Gregarina tenuis 1863 Gregarina tenuis Host: Allecula sp. No mention is made of this species among those in Labbe's Sporo- zoa or in the list of Sporozoa in Lankester 's Treatise (1903). The spe- cies is probably a true Gregarina, for Frantzius included in this genus only gregarines " — stets zu zweien aneinandergeheftet." He credits the discovery of the species to Hammerschmidt. GREGARINA ELONGATA Frantzius [Figure 154] 1848 Gregarina elongata Frantzius 1848 :193,195 1851 Gregarina elongata Diesing 1851 :13 1863 Gregarina elongata Lankester 1863 :94 Host : Crypticus sp. This species is well illustrated by Frantzius. It does not appear in Labbe's Sporozoa. GRBGARINA SCARABAEI Lankester 1851 Gregarina Scarabaei relicti Leidy 1851 :208,287 1863 Gregarina Scarabaei Lankester 1863:94 This species is known only from the original description, which is as f oUows : "Body cylindro-fusiform. Superior division presenting four sides of a hexa- hedron, subacute. Nuclear body of inferior division transparent, globular or ellip- tical, containing several coarse granules. Length from i/66 to J4 lines; headi 1/400 in. to 1/133 in. long, by 1/285 >"■ to i/lil in. broad. Anterior portion of inferior division 1/200 in. to 1/86 in. broad, posterior division 1/666 in. to 1/250 in. broad. Longitudinal lines of inferior division more distinct than those of upper division, 1/8000 in. apart." No drawing accompanies the description. Host : Scaraiaeus relictus larva. This species takes the first binomial name applied to it, that of Lankester. 385] STUDIES ON GREGARINES— WATSON • 175 GREGARINA PASS4LI Lankester [Figure 139] 1853 Gregarina passaU cornuti Leidy 1853 :238 1863 Gregarina PassaU Lankester 1863:94 1903 Gregarina passaU cornuti Crawley 1903:45 1913 Gregarina passaU cornuti Ellis 1913a :201 Gregarina: Sporonts biassociative, cylindrical. Length of associa- tions 350 to 400/i. Width not given. Ratio length protomerite : total length primite : : 1 : 5 ; width protomerite : width deutomerite : : 1 : 1. Protomerite dome shaped, flattened, 1^^ times as wide as high. Slight constriction at septum. Deutomerite cylindrical, sometimes con- stricted a little in middle. Posterior extremity broadly rounded or flat- tened. Bndocyte opaque ; nucleus spherical, content not mentioned. Taken at Philadelphia, Pa., and New Orleans, La. Host : Passalus cornutus Fab. Habitat: Intestine. Leidy 's figure represents sporonts with the deutomerite much wider than long. Crawley's figure is normal. Leidy probably left the animals on the slide in a water medium until they had become greatly distended before drawing them. Ellis recovered the same species from the same Lucanid, from Louisiana. This species takes the first binomial name, that of Lankester. The beetles of this host species at Urbana, Illinois, seem to be unin- fected. Twenty-five or more have been examined without finding an instance of parasitism with gregarines. They are abundantly supplied with nematodes. GREGARINA MELOLONTHAE Lankester 1856 Gregarina Melolonthae Brunneae Leidy 1856 :47 1863 Gregarina Melolonthae Lankester 1863:94 1913 Gregarina melolonthaeirunneae EUis 1913b :269 Gregarina: Sporonts biassociative, ellipsoidal. Length of primite 400/*, width 250/1. Ratio length protomerite : total length :: 1 : 4; width protomerite : width deutomerite :: 1 : 1.7. Protomerite ob- late spheroidal, slightly elevated at summit. Deutomerite oblong ovoi- dal. Taken at Philadelphia, Pa. Host: Melolontha irunnea. Habitat: Intestine. This species has not been redescribed. No drawings accompany Leidy 's brief record. Lankester shortened the name to a binomial and it is this name by which the species must be designated. EUis merely mentions the species. 176 ILLINOIS BIOLOGICAL MONOGRAPHS [386 GREGARINA MUNIBRI (Schneider) Labbe [Figures 128, 147] 1875 Clepsidrina Munieri Schneider 1875 :574-8 1899 Gregarina munieri Labbe 1899 :9-10 Gregarina: Sporonts biassociative, elongate ellipsoidal. Length and width not given. Ratio length protomerite : total length primite : : 1 : 6 to 1:7; width protomerite : width deutomerite : : 1:7. Protomerite cylindrical, flattened anteriorly, a little wider than high, less than 1.5 times, slight constriction at septum. Deutomerite cylindri- cal, ending bluntly or tapering slightly from middle and ending in a broad but rather pointed extremity. Epimerite a small spherical papiUa situated upon the apex of a short conical projection of the protomerite of the cephalont. Endocyte reddish orange. Nucleus spherical, with one karyosome. Cysts ovoidal. Spore ducts 3 to 6, reddish, very short, less than the radius of the cyst in length. Spores extruded in chains, spores barrel shaped, cylindrical, dilated through middle, terminating bluntly. Taken at Roscoff, France. Hosts : Timarcha tenebricosa (F.) ; Chrysomela violacea (Goeze) and C. haemoptera L. Habitat: Intestine. Schneider's argument concerning the species in question speaks for itself and is quoted here (1875:575) : " 'Dans le tube alimentaire de divers Coleopteres, notamment du Lucanus parallelopipedus, de plusieurs Melasomes et de la Timarcha tenebricosa, j'ai trouve abondamment une espece de Vers intestinaux, dont je joins ici le dessin.' Dufour, 1826. 'L'espece que j'ai dit habiter des entrailles de divers Coleopteres, merite, a cause de sa forme, le nom Conica.' Dufour, 1828. Si maintennant on se reporte a la figure indiquee par L. Dufour, on n'y trouve pas la designation de I'hote de I'in- dividu represente ; la legende portant simplement cette mention : 'Vers intestinaux trouves dans le tube alimentaire de divers Coleopteres.' II n'y a done aucun indice que I'auteur ait plus particulierement vise l'espece qui nous occupe, et comme il cite d'abord le Lucanus parallelopipedus, c'est a la Gregarine de ce Melolonthide qu'il conviendra de reserver I'epithete de Conica. Quant a l'espece actuelle, je I'ai dediee a mon excellent ami M. Munier Chalmas ." The species which Dufour found in Lucanus parallelopipedus is the species now named Actinocephalus conicus (Dufour) Frantzius. 387] STUDIES ON GREG ARINES— WATSON \77 GREGARINA LAUCOURNBTENSIS (Schneider) Labbe 1885 Clepsidrina Laucournetensis Schneider 1885a :28 1899 Gregarina laucournetensis Labbe 1899:11 Gregarina : Sporonts biassoeiative, obese. Length 60 to 70/* ; width 50-60/1. Cysts spherical, one spore duct. Spores elongate ovoidal, ex- truded in chains. Taken at ? Host: Parnus sp. Habitat: Intestine. GREGARINA STATIRAE Frenzel [Figure 138] 1892 Gregarina statirae Frenzel 1892:234-82 Sporonts biassoeiative, spheroidal. Length 300 to 350/*. Width 200/1. Ratio length protomerite : total length primite : : 1 : 5 ; width protomerite : width deutomerite :: 1 : 3.5. protomerite hemispheri- cal, widest at base, 1.7 times as wide as high. Deutomerite spherical, as wide as high. Nucleus spherical, with one karyosome. Endocyte dense except in anterior third of protomerite, where it is sparse. Epi- merite a simple short cylindrical papilla rounded at apex. Spores and cysts unknown. Taken at Cordoba, Argentina. Host: Statira unicolor Blanch. Habitat : Intestine. GREGARINA LONGIROSTRIS (Leger) Labbe [Figure 155] 1892 Clepsidrina longirostris Leger 1892:122-4 1899 Gregarina longirostris Labbe 1899:12 Gregarina : Sporonts biassoeiative, obese. lOO/i long. Ratio length protomerite : total length : : 1 : 4 ; width protomerite : width deu- tomerite : : 1 : 1.1. Protomerite conoidal, dilated in posterior half. No constriction at septum. Protomerite obovoidal. Nucleus spherical with one karyosome. Epimerite an elongate simple cylinder, 50 - 60/i long, one half or more than half as long as whole cephalont. Endoplasm greenish yellow. Cysts ovoidal, 60 to 70/i in diameter. One spore duct. Spores bar- rel shaped, 7.4 by 3.8/i. Taken in the valley of the Loire, France. Host : Thanasimus formi- earius (L.). Habitat: Intestine. 178 ILLINOIS BIOLOGICAL MONOGRAPHS [388 GREGARINA ACUTA (Leger) Labbe [Figure 217] 1892 Clepsidrina acuta Leger 1892 :121-2 1899 Oregarina acuta Labbe 1899 :11 Gregarina: Sporonts biassociative. Protomerite short, cylindrical, rounded in front. Deutomerite cylindrical, rounded behind. Nucleus spherical, with one karyosome. Epimerite a sharp point. Cyst and spores unknown. Taken at Poitou, France. Host: Trox perlatus Scriba. Habitat: Intestine. GREGARINA STEINI Bemdt [Figure 146] 1902 Gregarina steini Berndt 1902 :408-13 Gregarina : Sporonts biassociative, 42 to 150/t in length, width 16 to 30/t. Protomerite hemispherical. Constriction at septum. Deutomerite widest at shoulder, tapering to a more or less slender but well rounded posterior extremity. Epimerite a simple globular papilla. Cysts ovoidal, 70 to 100/* by 85 to 160/i. Cysts smaller than those of G. cuneata or G. polymorpha. Taken in Berlin, Germany. Host : Tenebrio molitor L. larva. Hab- itat : Intestine. The work on this species needs confirmation before it can be ac- cepted absolutely. Leger and Duboscq (1904:351-60) described the greg- arines of the larva of this beetle but made no mention of this species. No one of the previous workers on the same beetle has mentioned it. Not knowing how polymorphic G. polymorpha may be, the present writer does not wish to comment on this species. GREGARINA PARVA (Crawley) Watson [Figure 130] 1903 Gigaductus parvus Crawley 1908a :633-4 1913 Gigaductus parvus BUis 1913b :271 1916 Gregarina parva Watson (This paper} Gregarina: Sporonts biassociative, length 150/t; width 90/*. Ratio length protomerite : total length :: 1 : 5; width protomerite : width 389] STUDIES ON GREGARINES— WATSON 179 deutomerite :: 1 : 1.1 Protomerite subglobular, somewhat flattened anteriorly. Widest through middle portion. Width 1^^ times height. Deep constriction at septum. Deutomerite elongate ellipsoidal, widest about or little above middle, terminating bluntly. Nucleus large, spher- ical, content not noted. Endocyte coarsely granular, not dense. Cysts 170 to 200ju, in diameter, spherical, dehiscence by "one enor- mous spore duct." Spores cylindrical, 25 by 10/x, square cornered. Taken at Wyncote, Pa., and Vincennes, Ind. Hosts : Harpdlus cali- ginosus Fab. and H. pennsylvanicus Dej. Habitat: Intestine. Crawley created a genus Gigaductus for this species. The genus is described thus : "Cysts spherical, with a thin gelatinous envelope. Dehiscence by one enor- mous spore duct. Maturation period short. Spores cylindrical, very large. Wall single, thick. Spores marked with diagonal lines, those on one side opposed in direction to those on the other, giving the spore a latticed appearance. These lines are apparently due to the sporozoites, which make up a hollow cylinder lying in contact with the inner surface of the spore wall. The residuum, an ellipsoidal mass liberally provided with granules, occupies the cavity of this hollow cylinder." I have placed the species in question under the genus Gregarina. Several hitherto described species of the genus Gregarina have been re- corded to dehisce by one spore duct (e. g. G. laucournetensis; G. longi- rostris). It is to be noted that sometimes cysts of the genus Gregarina develop only one spore duct and others in the same fecal mass several. There is apparently no maximum-minimum limit to the number of ducts which may be present within the same species. GREGAEINA LUCANI (Crawley) Watson [Figure 150] 1903 Euspora lucani Crawley 1903:50-1 1916 Gregarina lucani Watson (This paper) Gregarina: Sporonts biassociative, elongate ellipsoidal. Length of associations 880/i,. Primite 520/* long, 128/t wide. Ratio length proto- merite : total length primite :: 1 : 10; width protomerite : width deutomerite : : 1 : 1.7. Protomerite flattened, widest through middle, twice as wide as high, deep constriction at septum. Deutomerite flat- tened or broadly rounded behind. Cyst and spores unknown. 180 ILLINOIS BIOLOGICAL MONOGRAPHS [390 Taken at Swarthmore, Pa. Host: Lucanus dama Thunb. Habitat: Intestine. BUis (1913a :264) says: "This species is referred to the genus Euspora because of the shape of the sporont and the coleopteran host, making the generic determination very uncer-' tain." The original description gives no evidence that the species is a member of the genus Euspora. The protomerite is not spherical and does not contain the conoidal, less dense area in its anterior third, and the spoi'es are not known and cannot be verified with those of the genus Euspora. The fact that the host is a beetle is of significance since the Euspor.-ie and the Gregarinae are both found in beetles. I have placed the species in the genus Gregarina because it is asso- ciative and does not have characteristics of the other associative genera. GREGARINA CAVALIERINA Blanchard 1905 Gregarina cavalierina Blanchard 1905 :926-8 Gregarina: Sporonts biassociative, the couple attaining a total length of 1500 to 2000/x. Length primite 500 to 1000//., width 80 to 100/t. Ratio length protomerite : total length primite : : 1 : 15 ; width proto- merite : width deutomerite? Protomerite flattened, ellipsoidal, longi- tudinal axis perpendicular to that of deutomerite. Deutomerite cylin- drical, rounded hemispherically at posterior end. Bndoeyte yellow in protomerite, darker in deutomerite. Nucleus spherical, 27/* in diameter, one karyosome. Cysts spherical, 400/t in diameter, dehiscing by spore ducts 200/* long, 40/1 wide at base and 15/t wide at end. Spores extruded in chains. Spores ellipsoidal, 8 by G/i. Taken in the mountains of Maure, France. Host : Dendarus (Pan- darus) tristis BjOssi (=coarcticollis Mis.) . Habitat: Intestine. GREGARINA SOGIALIS Leger 1906 Oregarina sociaUs Leger 1906:323-7 1911 Gregarina sociaUs Sokolow 1911 :279 Sokolow gives the reference to the original paper by Leger as Arch. Prot. 7 :106-30, but this reference is incorrect. The brief description and text figure are buried in a paper on another species and are not indexed. 391] STUDIES ON GREGARINES— WATSON 181 Sporonts in chain of 8 to 10 individuals ; average size IOO/a. Often 3 or 4 small sporonts at posterior extremity. Length protomerite : length deutomerite : : 1 : 5 or 1 : 6. Host: Eryx ater Fabr. larva. Ellis (1913c :79) refers to this paper as it is given above, but, it is obvious, did not see the paper in question. GREGARINA GUATEMALENSIS Ellis [Figure 144] 1912 Gregarina guatemalensis EUis 1912a :687-8 Gregarina ; Sporonts biassoeiative, the couple attaining 400 to 500/* in length. Width not given. Ratio length protomerite : total length primite :: 1 : 3 to 1 : 3.5; width protomerite : width deutomerite :: 1 : 2.5 to 1 : 7.5. Protomerite subglobose, slightly flattened and pointed at apex, faint constriction at septum. Deutomerite irregularly cylindrical, narrowest at septum, widening very gradually and greatly dilate in posterior fourth, terminating in a very broad flattened extrem- ity, the base nearly twice as wide as the deutomerite at the septum. The whole sporont is shaped like a salt cellar. Sarcocyte very thick, espe- cially in posterior portion of deutomerite. Endocyte of protomerite denser than that of deutomerite. Nucleus spherical, small. Taken at Quirigua, Guatemala. Host: Ninus interstitialis Esch. Habitat : Intestine. In Ellis' paper (1913b) the host genus is given as Nelus instead of Ninus as in the original description. GREGARINA GRISEA Ellis [Figure 151] 1913 Gregarina grisea Ellis 1913a :200-l Gregarina: Sporonts biassoeiative, cylindrical. Length of associa- tion 500 to 1050/t. Length primite 200 to 500/*. Ratio length protomerite : total length primite : : 1 : 4.5 to 1 : 6.5. Ratio width protomerite : width deutomerite : : 1 : 1 to 1 : 5. Protomerite hemispherical, wid- est at posterior margin, no constriction at septum. Deutomerite cylin- drical, tapering slightly to a broadly rounded posterior extremity. En- docyte dense, dark gray. Nucleus spherical. Cyst and spores not known. Taken at New Orleans, La. Host: Tenelrio castaneus Knoch. Habitat : Intestine. 182 ILLINOIS BIOLOGICAL MONOGRAPHS [392 GEEGARINA MINUTA Ishii [Figure 143] 1914 Gregarina minuta Ishii 1914:436-7 Gregarina: Sporonts biassociative, length of associations 118/*, length primite 58/*. Ratio length protonierite :: total length :: 1 : 9; width protomerite : width deutomerite : : 1 : 1.7. Protomerite some- what flattened, rounded anteriorly, twice as wide as high. No constric- tion at septum. Deutomerite cylindrical, broadly rounded at posterior end. Endocyte not dense. Nucleus large, spherical, with one karyosome. Cysts spherical, 36 by 48/t. Taken in the province of Izu, Japan. Host: TriboUum ferrugi- neum P. Habitat: Intestine. Under the name Gregarina minuta, the author described two greg- arines belonging to widely different families, one, the larger, being a Didymophyes (D. mi/nuta), from the absence of a protomerite in the sat- ellite, and the other the gregarine described above. For a detailed state- ment of these facts, see article in appendix of this chapter. GREGARINA KATHERINA Watson [Figure 171] 1915 Gregarina katherina Watson 1915:31 Host: Goccinella novcmnotata Herbst. Location : Oyster Bay, L. I., August, 1914. Percent of Infection: Fourteen lady beetles of various species were examined and only two found to be parasitized, one with this species, the other with G. iarharara Watson. The infection with this gregarine was very heavy, the whole alimentary tract being filled with parasites which numbered into hundreds. The gregarines were practically trans- parent and it was impossible to count them. The sporonts are biassociative when adult. The shape is that of a typical gregarine of this genus. The protomerite of the primite is wid- est at the mass, rounded at its free ends and more or less flattened at the apex. It is 1 1/4 to 1 1/2 times as wide as high, and constricted slightly at the septum. The protomerite of the satellite is flattened top and bottom and three to four times as wide as high. Its upper and lower surfaces are about equal in width. The deutomerite is cylindri- 393] STUDIES ON GREGARINES— WATSON 183 cal to ellipsoidal from 1-1/2 to two times as wide as is the protomerite ; it terminates in a broadly rounded posterior extremity. Color is practically absent from the animals for the body is almost transparent and contains very little protoplasm in either protomerite or deutomerite. The sporonts were stained with iodine or an anilin dye (safranin in water) before they could be studied. The nucleus is small and spherical, in diameter attaining only 1/3 to 1/4 the width of the deutomerite. It contains one large karyosome. Young individuals were seen attached to epithelial cells of the intes- tine by large smcft)th sessile transparent epimerites. No cysts were seen. Movement consists of very slow progression and a still slower con- tortion of the body. The character of the epimerite and the biassociative sporonts leaves no doubt that this species belongs to the genus Gregarina. It is differen- tiated from the other species found in the Coccinellidae by the shape and proportions of the sporonts, especially of the protomerite of the satel- lite, and by size. A table of dimensions of a few associations is given here ; all dimen- sions are expressed in microns : Total length association 96 108 134 141 148 Prpaite : Length protomerite 9 11 10 10 11 Length deutomerite 35 59 52 59 59 Width protomerite 11 17 19 20 14 Width deutomerite 21 30 30 34 30 Total length sporont 44 70 62 69 70 Batio length protom. : total length.-... 1:5 1:1.3 1:6.2 1:6.9 1:6.3 width protom. : width deutom....l :1.9 1 :1.8 1 :1.6 1 :1.7 1 :2.1 Satellite : Length protomerite _ 8 7 8 8 6 Length deutomerite 44 71 64 64 72 Width protomerite 14 26 20 20 21 Width deutomerite - 22 35 27 30 23 Total length sporont 53 78 72 72 78 Ratio length protom.: total length 1:6.5 1:11 1:9 1:9 1:13 width protom. : width deutom....! :1.6 1 :1.4 1 :1.3 1 :1.5 1 :1.1 Diameter nucleus 9 8 184 ILLINOIS BIOLOGICAL MONOGRAPHS [394 GREGARINA BARBARARA Watson [Figure 169] 1915 Gregarina harharara Watson 1915:31 Host : Goccinella sp. Fourteen lady beetles were examined and only two were parasitized, one with this species and the other with the preceding species. Sixteen associations of the present species were found in the one host. The re- gion of infection is the intestine. The adult sporonts are biassociative. In shape they are similar to other members of this genus. The primite is not essentially different in shape from that of G. katherina. The protomerites of the primite in the two species are identical, viz. 1 1/4 to 1 1/2 times as broad as high, cylindrical at the base and terminating in a broadly rounded, often api- cally flattened anterior extremity. The deutomerite of the primite of this species is more nearly globular, broadening appreciably backwards from the septum and attaining its greatest width in the middle or at the beginning of the posterior two thirds of the body. From here the deuto- merite rapidly contracts, ending in a very broadly rounded and not flattened posterior end. The shape of the satellite is quite different from that of the primite. It has the form of an elongated egg smaller at the posterior end. The satellite is generally longer than but is never as wide as the primite. The protomerite is very different from that of G. katherina. It is approximately five times as wide as high, and'twice as wide as the protomerite of the primite. It is broadly rounded in front and but imperfectly interlocked with the primite. The septum is straight or slightly concave upward, with no constriction whatever at its periphery, the protomerite and deutomerite forming a perfectly smooth contour at the edges of the septum. The deutomerite of the sat- ellite is widest a little behind the septum and anterior to the center of the egg shaped mass. The body gradually tapers from the region of greatest width, ending in a blunt, well rounded extremity. This parasite is practically transparent with a few large scattered darkly colored protoplasmic granules accumulated in the central re- gions of the deutomerite of the primite; the satellite is generally free from these dark colored inclusions. The nucleus is rarely obscured by protoplasm; it is small and spherical. The epicyte is very thin and fragile and the animals quickly break up when exposed to the diluted digestive juices of the host. 22 25 20 113 120 105 40 40 40 90 90 75 135 145 125 1:6 1:5.8 1:6.2 1:2.2 1:2.2 1:1.9 10 18 15 130 57 52 55 60 40 80 80 68 1:14 1:4.2 1:4.5 1:1.4 1:1.3 1:1.7 395] STUDIES ON GREGARINES— WATSON 185 A list of the essential measurements with dimensions in microns is appended : Total length association 283 275 220 192 Primite : Length protomerite 17 Length deutomerite 103 Width protomerite 28 Width deutomerite 80 Total length sporont 120 Eatio length protom. : total length 1 :7 width protom.: width deutomerite 1:2.5 Satellite : Length protomerite 17 Length deutomerite 46 Width protomerite 65 Width deutomerite 80 Ratio length protom.: total length 1:9.2 width protom. : width deutomerite 1 :1.2 Diameter nucleus 10 This species is considerably larger than Gregarina katherina. GEEGARINA FRAGILIS Watson [Figure 175] 1915 Gregarina fragilis Watson 1915 :32 Host : Coccinella sp. Location: Urbana, Illinois, November, 1914. The intestine of the host is the seat of infection. Out of thirty or more lady beetles of many species which were examined, only two yielded parasites. About twenty-five associations were found in the two hosts. The sporonts are biassociative. The protomerite of the primite is cylindrical, rounded at the corners and nearly flattened anteriorly ; it is about 1 2/3 times as wide as high. A shallow constriction or none at all is present at the septum. In the satellite, the protomerite is altered slightly in shape, being both flattened and broadened. The deutomerite is subglobular, widest in the middle or slightly posterior to the middle and terminates in a broadly rounded extremity. The satellite is smaller than the primite and less nearly globular in shape. 186 ILLINOIS BIOLOGICAL MONOGRAPHS [396 This parasite is often practically transparent and can only be seen after stainipg with iodine or a dye in watef . The largest specimens con- tain endocyte tinged with tan color in the deutomerite, while the proto- merite is invariably colorless. The nucleus is spherical and small, one third to one fourth the width of the deutomerite in its diameter ; it is in- visible in vivo and contains one large transparent karyosome. Trophozoites were seen but the epimerite was not visible because of the transparency when embedded. Cysts are unknown. Measurements of two associations are as follows; all dimensions are cited in microns : Total length association 185 208 Primite : Length protomerite . Length deutomerite . Width protomerite ... "Width deutomerite .... Total length sporont Ratio length protom. : total length.. width protom.: width deutomerite. Satellite : Length protomerite Length deutomerite Width protomerite _._ Width deutomerite Total length sporont Batio length protom.: total length.. 20 21 80 90 33 31 61 60 100 111 1:5 1:5 1:2 1:2 20 20 .65 77 33 31 43 48 ,85 97 :4.2 1:4.8 :1.3 1:1.5 10 11 width protom. : width deutomerite 1 :1.3 Diameter nucleus _ This species differs from the other two species described from Coc- cinellidae in size, shape of the protomerite of the satellite and in color. 397] STUDIES ON GREGARINES— WATSON 187 GREGARINA TENEBRIONELLA Watson [Figure 174] 1915 Oregarina tenebrionella "Watson 1915:32 Host: Larva of an unidentified member of the family Tenebrioni- dae. Location: IJrbana, Illinois, October, 1914. The intestine of the host was heavily infected, with a hundred or more associations. The sporonts are biassociative and the shape is that characteristic of this genius. The animals are very small and subglobular. The protome- rite of the primite is as wide at the base as throughout the posterior third of the body. Its anterior end is weU rounded, without a papilla at the apex. In the satellite, the width of the protomerite is about equal to the height, although it is more or less flattened top and bottom. The length of the protomerite of the primite is one fourth the total length. The deuto- merite of the primite is short, broad, globose, widest through the median portion and broadly rounded behind. In the satellite it tapers slightly and is less globular in shape, being one third to four fifths as wide as the deutomerite of the primite. The primite is larger in every instance re- corded than the satellite, often longer by one third. The color of this species is pale gray. The protoplasm is not dense in any part of the body and the protomerite is almost devoid of protoplasm. The granules of the body are not homogeneous, smaller being interspersed with larger. The satellite is more nearly transparent than the primite. The nucleus is spherical, one fourth to one third the width of the deuto- merite in its diameter ; it is not visible in vivo in the primite but generally so in the satellite. The interlocking device between the sporonts is weakly developed and the individuals often barely touching are easily displaced. Trophozoites and cysts were not seen. Movement consists of a slow uni- form progression ; contortion was not noted. A table of measurements follows, in which dimensions are given in microns : Total length association 140 137 129 109 Primite : Length protomerite — — Length deutomerite Width protomerite - Width deutomerite — Total length sporont Ratio length protom. : total length 1 :4.1 width protom.: width deutomerite — 17 18 15 16 53 53 46 46 23 20 25 20 42 37 38 35 70 70 61 62 ;4.1 1:3.9 1:4 1:3.9 1.8 1:1.8 1:1.5 1:1.7 188 ILLINOIS BIOLOGICAL MONOGRAPHS [398 Satellite : Length protomerite 13 17 18 10 Length deutomerite _....■ .-... 57 50 50 37 Width protomerite 28 20 28 16 Width deutomerite -... 32 30 50 18 Total length sporont - 70 67 68 47 Eatio length protom. : total length 1 :5.4 1 :4 1 :3.8 1 :4.7 width protom. : width deutomerite. 1 :1.2 1 -.1.5 1 :1.8 1 :1.1 Diameter nucleus 10 8 9 Shape and size _ differentiate this species from all the other species found in the Tenehrionidae. For list of these gregarines, see Index of this chapter on Coleopteran parasites. GREGAEINA GRACILIS Watson [Figure 170] 1915 Gregarina gracilis Watson 1915 :32 Host : Larva of an unidentified member of the family Elateridae. Location : Urbana, Illinois, October, 1914. The parasites infect the intestine of the host. The sporonts are biassociative. The satellite is generally the larger, contrary to the general rule that either the primite is slightly the larger or the two sporonts differ but little in size. The body is elongate cylindrical, rather longer in proportion than is true of most members of the genus. The protomerite of the primite is hemispherical with no papilla or inden- tation at the anterior end. The constriction at the septum is shallow ; the protomerite is one and one third times as broad as high and averages one sixth the total length of the sporont. The protomerite of the satellite is of practically the same width as that of the primite, but is slightly flat- tened. The deutomerite is elongate cylindrical, a little wider in the mid- dle portion and tapering slightly, ending in a broadly rounded extrem- ity. The interlocking device is not well constructed, sporonts of an asso- ciation being barely contiguous and easily dissociated by slight pressure. The body is pearl gray, and the protoplasm is not homogeneous but consists of large and small granules sparsely scattered throughout. The anterior end of the protomerite is devoid of granules. The nucleus is not visible in adults not because of the density of the protoplasm but because of the fact that the large granules seem to cling to or lie in the region of the nucleus in a cluster. The region occupied by the nucleus can, there- fore, be easily detected although its outline is obscured. The nucleus is 399] STUDIES ON GREGARINES— WATSON 189 small and spherical, containing one small karyosome. In one instance, the chromatin was arranged outside the karyosome as in the spokes of a wheel, the karyosome forming the eccentric hub. The epicyte is very thin and of even width throughout. A table of measurements of sporonts follows ; the dimensions are ex- pressed in microns : Total length association 368 355 310 237 Primite : Length protomerite _.. 20 20 21 20 Length deutomerite 158 105 129 97 "Width protomerite 35 30 30 23 Width deutomerite - -.. 75 50 57 41 Total length sporont 178 125 150 117 Katio length protom.: total length. 1:8.9 1:6.2 1:7.1 1:5.8' width protom.: width deutomerite 1:2.1 1:1.7 1:1.9 1:1.9 Satellite : Length protomerite - 21 20 20 20 Length deutomerite 169 160 140 100 Width protomerite 41 35 35 32 Width deutomerite 80 75 65 45 Total length sporont 190 180 160 120 Hatio length protom. : total length 1 :9 1 :9 1 :8 1 :6 width protom.: width deutomerite.... 1:2 1:2.1 1:1.9 1:1.4 GREGARINA INTESTINALIS Watson [Figure 168] 1915 Gregarina intestinalis Watson 1915 :32 Host: Pterostichus stygicus (Say) Location : Urbana, Illinois, November, 1914. A dozen associations were found in the intestine of one beetle. The beetle was also infected with Gregarina monarchia. The sporonts are biassociative. The body is ellipsoidal to subglobose. The protomerite of the primite is subspherical, weU rounded in front, widest along the center, equal in width to one fourth to one sixth the width of the deutomerite, and one fifth the total length. There is a fairly deep constriction at the septum. The deutomerite is egg-shaped, widest about the. middle portion or slightly posterior to the middle. The poste- rior end is broadly rounded in the primite and slightly more tapering in 190 ILLINOIS BIOLOGICAL MONOGRAPHS [400 the satellite. The individuals of an association are easily detached by slight pressure. In color, this species is dark and gray, especially in the deutomerite ; the protomerite is less dense. The nucleus is not visible in the live animal. Trophozoites and cysts were not seen. A table of measurements, in which dimensions are given in microns, follows : Total length association 320 304 Primite : Length protomerite 40 33 30 35 Length deutomerite 120 137 130 135 Width protomerite 45 42 42 55 Width deutomerite :.- 80 80 70 82 Total length sporont 160 170 150 170 Eatio length protom. : total length 1 :4 1 :5 1 :5 1 :5 width protom. : width deutomerite 1 :2 1 :2 1 :1.6 1 :1.5 Satellite : Length protomerite _ 30 20 Length deutomerite 130 114 Width protomerite 50 32 Width deutomerite 70 75 Total length sporont 160 134 Ratio length protom. : total length 1 :5.3 1 :6.7 width protom. : width deutomerite 1 :1.4 1 :2.3 GREGARINA MONARCHIA Watson [Figure 167] 1915 Gregarina monarchia Watson 1915 :31 lEost -.Pterostichus stygicus (Say). Location : Urbana, Illinois, November, 1914. Only one parasite was seen in the intestine of the host. The same beetle was infected with Oregarina fragiUs. The sporonts are biassociative. The body is very long and sausage shaped, easily visible to the eye. The protomerite of the primite is dome shaped, widest just below the middle portion, is but little wider than high, and in length equal to one seventh the total length of the sporont. There is a deep constriction at the septum. The deutomerite is cylindrical, of 401] STUDIES ON GREGARINES— WATSON 191 even width throughout and but little wider than the protomerite. It is broadly rounded at the free extremity. The protomerite of the satellite is flattened top and bottom, twice as wide as high, and in length averages; one sixteenth the total length of the satellite. The interlocking device be- tween primite and satellite is deep and well developed. The body is black, the protoplasm being very dense in all parts ex- cept the protomerite of the primite. This portion is nearly transparent except for its lower portion in which the protoplasm is dense and darkly colored. A deep groove runs crosswise just anterior to the middle portion of the protomerite and in front of it is a clear vesicular area rather indis- tinct in outline. The epicyte is rather thick and of the same width throughout except in the protomerite of the satellite. It is considerably thicker at the place of interlocking and a little thicker on the sides of this protomerite than elsewhere in the association. Trophozoites and cysts; were not recovered. Movement of progression was not noted, but a slow contortion was evinced by a slight curving of the body. Measurements of the one association seen are as follows, with the di- mensions stated in microns : Total length association _ 1070 Primite Satellite Length protomerite 80 32 Length deutomerite 490 468 Width protomerite 110 115 Width deutomerite - 130 162 Total length sporont 570 500 Eatio length protom. : total length _ _ 1 :7 1 :16 width protom. : width deutomerite _ 1 :1.2 1 :1.4 GEEGARINA GLOBOSA Watson [Figure 176] 1915 Gregarina glohosa Watson 1915:31 Host: Coptotomus interrogatus (Fab.). Location : Urbana, Illinois, November, 1914. The intestine of the host was infected ; two beetles out of six exam- ined contained two associations each. The sporonts are biassociative. The body is subspherical, the proto- merite of the primite twice as wide as high and hemispherical but rather flattened at the top. There is a constriction at the septum but it is shal- 192 ILLINOIS BIOLOGICAL MONOGRAPHS [402 low and scarcely noticeable in the satellite. The deutomerite is stout, three fourths as wide as long ; it increases gradually in width up to the l)egianing of the posterior third of the body, when it becomes rapidly nar- rower, ending in a very broadly rounded extremity. The protomerite of the satellite is larger than that of the primite, which possibly indicates sexual dimorphism. The primite and satellite are not well interlocked. The endocyte of the primite is dense and is not visible in vivo. The «ndocyte of the satellite is paler, revealing the presence of a spherical nu- cleus. Trophozoite and cysts were not found. A table of measurements of one association follows in which all di- mensions are given in microns : Primite Satellite Length protomerite .... Length deutomerite . "Width protomerite ... "Width deutomerite Total length sporont Eatio length protom. : total length- width protom. : width deutomerite.. 230 165 75 110 180 155 260 210 ,1:8.6 1:1.4 .1 :2.4 1:1.4 GRBGARINA PLATYNI nov. spec. [Figures 262, 263, 264] Host: Platynus ruficollis Marsh (Det. Dr. E. P. Felt). Location: Oyster Bay, L. I., October, 1915. The host of this species is a very small black beetle which flew in my study window one evening. Several hundred parasites were found in the intestine of the single host. The sporonts are biassoeiative. They are elongate cylindrical in shape and generally lie in a slightly curved position. The largest associa- tion measured GlOfi. in length while sporonts averaged 300/t in length and 60/t in width. The average ratio of length protomerite : total length sporont : : 1 : 4.3 and the ratio width protomerite : width deutomerite : : 1 : 1. The protomerite is characterized by a constriction in the mid- dle which is deep and conspicuous in sporonts of all ages and the proto- plasm is much less abundant above the constriction than below. There is a deep constriction at the septum between protomerite and deutomerite. The apex of the protomerite is rounded, sometimes rather acutely while the deutomerite is cylindrical, attaining a maximum width just behind the constriction and tapering slightly in the posterior two thirds. The ■403] STUDIES ON GREGARINES— WATSON 193 extremity is bluntly rounded. The protomerite of the satellite does not show the constriction which characterizes that of the primite. It is low and flat and slightly wider than long. The constriction at the septum is not as deep here as in the primite. The attachment of the two sporonts of an association is very insecure. The nucleus is large and spherical, often being in diameter half the width of the deutomerite. It is conspicuous in sporonts of all ages. The j)rotoplasm is very dark in color — often black in the deutomerite but it is not as dense as that of many gregarines. It readily accumulates in masses, leaving clear spaces between. The protomerite is much less dense and tan in color; the portion above the constriction is almost devoid of protoplasm. The epimerite is spherical and very large. Myonemes are large and conspicuous, even in the adults. Movement is active. Cysts were not recovered. A table of the more important measurements follows with dimen- sions expressed in microns : Total length association 610 600 550 Primite : Length protomerite 70 70 60 Length deutomerite 230 230 180 Width protomerite - 110 60 60 Width deutomerite 110 60 70 Total length sporont 300 300 240 Ratio length protom. : total length..... _ 1 :4.3 1 :4.3 1 :4 width protom. : width deutomerite _ — 1 :1 1 :1 1 :1.1 -Satellite : Length protomerite 50 40 50 Length deutomerite 260 260 260 Width protomerite - 100 40 70 Width deutomerite 100 70 80 Total length sporont - - 310 300 310 Ratio length protom. : total length 1 :6.2 1 :7.5 1 :6.2 width protom. : width deutomerite 1 :1 1 :1.7 1 :1.1 This species is almost unique in the possession of a deep constricting groove in the protomerite of the primite. This feature, together with the long cylindrical deutomerite, readily differentiates it from other species. 194 ILLINOIS BIOLOGICAL MONOGRAPHS [404 UNCERTAIN SPECIES IN THE GENUS GEEGAEINA GREGAEINA ELATERAE Crawley [Figure 158] 1903 Gregarina elaterae Crawley 1903 :46 Sporonts not seen. Crawley's description is based evidently on the cephalonts and a species can hardly be assigned to material containing no mature specimens for the cephalonts of many of the Gregarinidae are identical. Crawley's description is in part as follows : "Epimerite spherical, protomerite elliptical, long axis perperdicular to that of deutomerite, sharp constriction at septum. Deutomerite oval to subspherical. Endocyte characteristic of cephalonts, sparse and granular. Max. length 62,14. Host Elater sp, larva. Taken at Wyncote, Pa." The species is probably a member of the genus Gregarina from the epimerite, but it cannot stand as absolute. Subsequent discovery of the sporonts probably cannot be correlated with the cephalonts here described owing to a similarity of the cephalonts of so many species. GREGARINA CURVATA (Frantzius) Diesing 1838 Bhizinia sp. Hammerschmidt 1838:356 1848 Sporadina curvata Frantzius 1848 :195 1851 Gregarina curvata Diesing 1851:14 1863 Gregarifia curvata Lankester 1863 :94 The following and only description of the species available is quoted from Diesing: "Proboscis ? . Receptaculum rotundatum. Corpus elongatum retrorsum attenuatum curvatum, receptaculo sexies longius. Longit. %-%'"." Host: Cetonia aurata larv. Habitat: Intestine. Frantzius merely names the species, giving neither drawing nor description. Diesing gives no clue as to whether the species is biasso- ciative or not. Lankester places it in the genus Gregarina, which he characterizes by the phrase "two animals frequently hanging together" giving no description. The species has not since been mentioned in the literature, and in lieu of complete data, it is placed in the group of doubtful species under the genus Gregarina. 405] STUDIES ON GREGARINES— WATSON 195 UNCERTAIN SPECIES OF UNCERTAIN FAMILIES GEEGARINA BOLETOPHAGI Crawley [Figure 145] 1903 Gregarina ioletophagi Crawley 1903-47-8 Sporonts not associative, cylindrical, 320/^ in length. "Protomerite large, variable in shape. Separated from deutomerite by a sharp constriction. Deutomerite cylindrical, with conical end. Endocyte dense, nucleus oval to spherical, with one karyosome. Epimerite not seen. Host: Boletophagus cornutus. Locality Swarthmore, Pa." Ellis (1913b :280) says "This species has been transferred to this genus (Anthorhynchus) from Gregarina although neither cysts nor epimerite are known, because it is not found in association and because the anterior portion of the protomerite is suggestive of the slightly produced protomerite of other species of the genus Anthorhynchus which bear epimerites. It is to be regarded as a provisional determination only.'' No characteristics of the genus Anthorhynchus are evident. The epimerite, not being seen, cannot be compared with the very large glo- bular epimerite of the latter genus and the spores cannot be compared, not being seen. The size of the species in question is only one seventh that of the type species of the genus Anthorhynchus (A. sophiae Schn.). It seems that the only solution of the problem is the relegation of the species to the uncertain group. GREGARINA MICROCEPHALA Leidy [Figure 149] 1889 Gregarina microcephala Leidy 1889 :11 "Body clavate, the head like a watch crystal with a little ball at the summit." Length 350/^, width 100/*, head 12fi long x 40/* wide. Taken at Philadelphia, Pa. Host: Arrhenoplita Mcornis Olivier (Eoplocephalus ti.). Habitat: Intestine. Ellis (1913b) corrected the host name. He left the species in the genus Gregarina. Leidy said of the species : "It bears a close resemblance to Echinocephalus hispidis Schneider but in the one described I at no time found digitiform appendages on the head." That the species belongs in the genus Gregarina seems doubtful ; its position is left undetermined. 196 ILLINOIS BIOLOGICAL MONOGRAPHS [406 GRBGAEINA OVALIS (Crawley) Watson [Figures 156, 157] 1903 Eirmocystis ovalis Crawley 1903 :50 1913 Gregarina elaterae Ellis 1913b :270 1916 Gregarina ovalis "Watson (This paper) Sporonts cylindrical, 70/* long, width not given. Ratio length pro- tomerite : total length : : 1 : 4 ; width protomerite : width deutome- rite : : 1 : 1.1 Protomerite hemispherical, widest at base. Slight con- striction at septum. Deutomerite dilated at shoulder, cylindrical, end- ing very bluntly. Endocyte dark brown. Anterior third of protomerite free from granules. Nucleus not seen. Cyst and spores unknown. Taken at Wyncote, Pa. Host: Cucujidae larva ("doubtful det."). Habitat : Intestine. This species is probably associative but adult sporonts have not been found. The specimens illustrated are probably mature. The length is less than in most adult gregarines. Ellis placed the species and Crawley's Gregarina elaterae together under the name of the latter. I have rather regarded the latter species as a doubtful one and have left this gregarine under its original name but questioning the correctness of the genus name. The species cannot be assigned to the genus Gregarina without a question of doubt arising. It is therefore placed with the uncertain species. GREGARINA COPTOTOMI nov. spec. [Figure 172] Host : Coptotomus interrogatus (Fab.) . Location : Urbana, Illinois, November, 1914. Two hosts each contained one parasite in the intestine. The sporonts are solitary. In shape the body is elongate ellipsoidal. The protomerite is cylindrical at the base with a broadly rounded coni- cal apex; it is as wide as high and the widest part is just anterior to the septum. There is no constriction at the septum. The deutomerite is elongate ellipsoidal broadening rapidly from the septum and soon at- taining its maximum width. It remains of the same width throughout most of the length, terminating in a very broadly rounded blunt ex- tremity. The endocyte is gray and not dense, for the nucleus is clearly 407] STUDIES ON GREGARINES— WATSON 197 visible in vivo as an ellipsoidal body twice as long as wide and contain- ing one large karyosome. Trophozoites and cysts have not been ob- served. Measurements are as follows with dimensions given in microns : Total length sporont 210 125 Length protomerite _ 30 18 Length deutomerite 180 107 Width protomerite 35 28 Width deutomerite 80 . 38 Ratio length protom. : total length 1 :7 1 :7 width protom. : width deutomerite 1 :2.3 1 :1.3 Nucleus 41 by 20 23 by 10 It is very probable that these specimens are not members of the genus Gregarina. The ellipsoidal nucleus is like that of some of the Ac- tinocephalidae. No attempt is made to place the specimens, and they are mentioned for the completeness of the record only. STYLOCEPHALUS sp. [Figure 65] ?1875 Stylocephalus longicollis Schneider 1875 : PI. xix, fig. 2 The following description is copied from Crawley (1903 :47) : "Gregarina xylopini Crawley. The two gregarines shown in figures 29 and 30 are stated by Leidy to be parasites of the beetle Xylopinus saperdioides. Of the six beetles examined, five contained gregarines of the form shown in figure 29, one of the form shown in figure 30. These two forms are so dissimilar that it appears better, at present, to give only the figures, reserving the description until additional information is at hand." Figure 29 is reproduced in my figure 65 ; figure 30 in my figure 134. The first gregariae agrees in appearance with sporonts of Schneider. Ellis considers it as sjmonymous with his AcUnocephalus zophus, I do not, however, regard it as such, but as a separate species. See dis- cussion under A. zophus. The second gregarine, (Figure 134) is evidently a specimen of Greg- arina cuneata. The host is one of the Tenebrionidae and the drawing compares very favorably with the others listed under 6?. cuneata Stein. 198 ILLINOIS BIOLOGICAL MONOGRAPHS [408 GRBGARINA sp. Crawley [Figure 105] "Asierophora philica Crawley. Gregarina philica Leidy (1889). It is impos- sible to give a description of this species. Figures 31 and 32 are very plainly of the same gregarine, virhereas figure 33 seems almost certainly to belong to a differ- ent species. Further, the form figured by Leidy in 1889 is not so closely like that shown in figures 31 and 32 as to render it certain that the two are the same. I therefore include the three different forms under the same name, giving only the figures and reference, until such time as sufficient material is obtained to determine accurately what the actual facts may be. The gregarines figured were about 300 microns long." (Crawley, 1903:53)- The first two gregarines have been described under the name Asiero- phora philica (Leidy) Crawley. The third is certainly very different from the others and merits isolation. Its generic position is undeter- mined from lack of data and it is mentioned here simply for complete- ness of the record. APPENDIX AN UNNAMED DIDTMOPHTES PKOM A JAPANESE BEETLE In a recent article on the parasites in the intestine of a Japanese beetle, Tribolium ferrugineum ¥., (Tenebrionidae), S. Ishii (1914) has evidently confused two species of Polycystid Gregarines and designated them by the same name. He described two kinds of associations, large and small, as Gregarina mi/nuta, but from his drawings and measure- ments the specimens are unlike. The protomerite of the primite in the first (Fig. 71) is large, subglobose, nearly flattened on the anterior sur- face, five eighths as wide as the deutomerite at its widest portion, and three fifths as high as wide. Its widest portion is some little distance an- terior to the septum. At the septum, there is a deep constriction, the pro- tomerite just anterior to it being wider than the deutomerite just poste- rior to it. In figure 143, the protomerite of the primite is smaller in pro- portion than in figure 71, hemispherical in shape, widest on its posterior margin, two thirds as wide as the deutomerite at its widest part, and half as high as broad. It is narrower at the septum than is the deutomerite just posterior to the septum. Thus there is a smooth, rounded contour 409] STUDIES ON GREGARINES— WATSON 199 along the edge of the septum. The length given for the larger associa- tions is 188/i, for the smaller llSju,. In his general description, Ishii says "the protomerite in the satel- lite is not infrequently hidden from view, being entirely embedded in the deutomerite of the primite."* In his table of measurements, he says of the satellite "protomerite absent." Later he mentions "the frequent ab- sence of protomerite in the satellite." The figure of the larger associa- tion (Fig. 71) lacks a protomerite in the satellite; the figure of the smaller (Figure 143) shows a protomerite and the table of measure- ments corroborates its presence. Absence of protomerite in the satellite is not one of the diagnostic features of the genus Gregarina. If the protomerite had been absent in rare instances, the sporont might have been a "sport", but its fre- quent absence is, clearly enough, reason for removing the specimens from the genus Gregarina. Absence of the protomerite of the satellite is the chief diagnostic character of the family Didymophyidae, in which there is but one genus, Didymophyes, and of this family only. Therefore this polycystid greg- arine which lacks a protomerite in the satellite belongs to the latter genus and I have (p. 133) designated it Didymophyes minuta (Ishii) . Of course, the determination cannot be absolute without the spores and epi- merite, but if the specimens belong to any known genus, they must be- long to the genus Didymophyes. Of the four hitherto described species in this genus, two have been recovered from Coleoptera. The present species is the smallest to be re- corded, by 67/t. (D. longissima Sieb.). The smaller associations which Ishii described and in which the pro- tomerite of the satellite is present, belong, without doubt, to the genus Gregarina, and the name G. minuta refers to them only. There is also either a confusion of species or an error in observa- tion in regard to the species Gregarina crassa (Ishii, 1914:438). He il- lustrates but one specimen and, in this one indistinct figure, it is impos- sible to determine whether or not there is a protomerite in the satellite. Since only one specimen is measured and but one drawn, no compari- sons can be made between the specimens with and those without proto- merites in the satellites and I am unable to determine the number of species under consideration and the systematic position of the specimen described. *This statement is construed to mean that the author did not see the proto- merite of the satellite and inferred that it was embedded in the deutomerite of the primite. 200 ILLINOIS BIOLOGICAL MONOGRAPHS [410 PART IV THE CEPHALINE GREGARINES OF THE WORLD TOGETHER WITH THEIE HOSTS Parasite Host Order or Class DIDYMOPHYIDAE phyes gigantea Oryctes nasicornis (L.) Oryctes sp. Phyllognathus sp. Coleoptera leuckarti Aphodius prodromus (Brahm.) Aphodius nitidulus F. Coleoptera longissima Gammarus pulex (L.) Orchestia littorea Leach Crustacea minuta Triholium ferrugineum F. Coleoptera paradoxa Geotrupes stercorarius (L.) Coleoptera GREGARINIDAE Gregarina achetaeabbreviatae acridiorum acuta amarae barbarara blattarum boletophagi cavalierina clausi conica consobrina coptotomi cuneata curvata davini elaterae elongata ensiformis flava fragilis galliveri gammari globosa Gryllus abbreviatus Serv. Pamphagus sp. Tryxalis sp. Sphingonotus sp. Trox perlatus Scriba Poecilus cupreus (L.) Coccinella sp. Periplaneta americana (L.) Periplaneta orientalis (L.) Blattella germanica (L.) Boletophagus cornutus Panz. Dendarus trisiis Rossi Phronima sp. Coleoptera and Orthoptera Ceuthophilus valgus Scud. Coptotomus interrogatus (Fab.) Tenebrio molitor L. Cetonia aurata L. Gryllomorpha dalmatina Ocsk. Elater sp. Crypticus sp. Salpa aeruginosa Salpa confoederata Salpa vagina Coccinella sp. Gryllus abbreviatus Serv. Gammarus sp. Coptotomus interrogatus (Fab.) Orthoptera Orthoptera Coleoptera Coleoptera Coleoptera Orthoptera Orthoptera Orthoptera Coleoptera Coleoptera Crustacea Orthoptera Coleoptera Coleoptera Coleoptera Orthoptera Coleoptera Coleoptera Tunicata Tunicata Tunicata Coleoptera Orthoptera Crustacea Coleoptera 411] STUDIES ON GREGARINES— WATSON 201 Parasite Host Order or Class gracilis Elater sp. Coleoptera granulosa Ephemera sp. Neuroptera grisea Tenebrio castaneus Knoch Coleoptera guatemalensis Minus interstitialis Esch. Coleoptera hyalocephala Tridactylus variegatus Latr. Orthoptera illinensis Ischnoptera pennsylvanica (deGeer) Orthoptera intestinalis Pterostichus stygicus (Say) Coleoptera katherina Coccinella novemnotata Herbst Coleoptera kingi Gryllus abbreviatus Serv. Orthoptera lagenoides Lepisma saccharina L. Thysanura laucournetensis Parnus sp. Coleoptera locustae Dissosteira Carolina L. Orthoptera longa Tipula sp. Diptera longiducta Ceuthophilus maculatus (Say) Orthoptera Ceuthophilus latens Scud. Orthoptera longirostris Thanasinius formicarius (L.) Coleoptera lucani Lucanus dama Thunb. Coleoptera macrocephala Nemobius sylvestris (F.) Orthoptera Gryllus domesticus L. Orthoptera marteli Embia sp. Neuroptera melolonthae Melolontha brunnea Blanch. Coleoptera microcephala Arrhenoplita bicornis Oliv. Coleoptera miliaria Gammarus sp. Crustacea Astacus sp. Crustacea minuta Tribolium ferrugineum F. Coleoptera monarchia Pterostichus stygicus (Say) Coleoptera munieri Timarcha tenebricosa (F.) Coleoptera Chrysomela violacea (Goeze) Coleoptera Chrysomela haemoptera L. Coleoptera mystacidorum Mystacida sp. Neuroptera nereidis denticulata ? Annelida nigra Acridiidae Orthoptera oblonga Oedipoda migratoria L. Oedipoda stridula L. Orthoptera Gryllus campestris L. Orthoptera ovalis Cucujidae Coleoptera ovata Forficula auricularia L. Orthoptera oviceps Gryllus abbreviatus Serv. Gryllus americanus Blatch. Orthoptera panchlorae Panchlora exoleta Klug Orthoptera paranensis Schistocerca paranensis Burm. Orthoptera parva Harpalus caliginous Fab. Coleoptera passalii Harpalus pennsylvanicus Dej. Passalus cornutus Fab. Coleoptera 202 ILLINOIS BIOLOGICAL MONOGRAPHS [412 Parasite Host Order or Class platyni Platynus ruficollis Marsh Coleoptera podurae Orchesella villosa Thysanura polymorpha Tenebrio molitor L. Coleoptera praemorsa Platycarcinus sp. Crustacea psocorum Psocus sp. Neuroptera pterotracheae Ptero trachea sp. MoUusca rigida Acridiidae Orthoptera salpae Salpa maxima Tunicata scarabaei S carabaeus relictus Coleoptera serpentula Periplaneta orientalis (L.) Orthoptera socialis Eryx ater Fab. Coleoptera soror uncertain Coleoptera sphaerulosa Gryllotalpa sp. Locustidae statirae Statira unicolor Blanch. Coleoptera steini Tenebrio molitor L. Coleoptera stygia Ceuthophilus stygius (Scud.) Orthoptera tenebrionella Tenebrionidae Coleoptera tenuis Allecula sp. Coleoptera termitis Termes sp. Neuroptera tipula Tipula sp. Diptera udeopsyllae Udeopsylla nigra Locustidae valettei PoUicipes sp. Crustacea sp. (Bolsius) Glossiphonia sp. Herpobdella sp. Annelida sp. (Crawley) Nyctobates pennsylvanica (deGeer) Coleoptera sp. (Gaede) Blaps mortisaga L. Coleoptera sp. (Hallez) Dendrocoelum lacteum Platyhelminthes sp. (Kolliker) Balanus sp. Crustacea sp. (Mawrodiadi) Balanus sp. Crustacea sp. (Moseley) Peripatus sp. Onycophora sp. (Pfeiffer) Gammarus pulex Crustacea sp. (Porter) Rhynchobolus americanus Annelida sp. (Ritter) Perophora annectens Tunicata sp. (Solger) Balanus improvisus Crustacea Hirmocystis asidae Asida servillei Sol. Coleoptera grylloialpae Gryllotalpa gryllotalpa (L.) Orthoptera harpali Harpalus pennsylvanicus eryth- ropus (Dej.) Coleoptera polymorpha Limnobia sp. Diptera ventricosa Tipula sp. Diptera Pachyrhina sp. Diptera Sphaerocystis simplex Cyphon pallidulus Boh. Coleoptera Hyalospora affinis Machilis cylindrica Geoff. Thysanura reduvii Reduvius personatus L. Hemiptera 413] STUDIES ON GREGARINES— WATSON 203 Parasite roscoviaha Cnemidospora lutea Euspora fallax Gamocystis ephemerae tenax Frenzelina chtamali conformis delphinia dromiae fossor nigrofusca ocellata olivia portunidarum praemorsa Uradiophora communis cuenoti Leidyana erratica gryllorum DACTYLOPHORIDAE Dactylophorus robustus Nina giardi giardi corsicum gracilis indicia Trichorhynchus pulcher Echinomera hispida horrida Rhopalonia geophili Stella Acutispora macrocephala Metamera schubergi ACTINOCEPHALIDAE Actinocephalus acutispora americanus brachydactylus caudatus conicus Host Perobius maritimus Leach Glomeris sp. Rhizotrogus aestivus Oliv. Ephemera sp. Blattella lapponica L. Chtamalus stellatus Pachygraspus marmoratus Talorchestia longicornis Oromia dromia Pinnotheres pisum Uca pugnax and Uca pugilator Eupagurus prideauxi Libinia dubia Portunus arcuatus Cancer pagurus Balanus sp. Atyaephyra desmaresti Gryllus abbreviatus Serv. Gryllus pennsylvanicus B'urm. Gryllus domesticus (L.) Cryptops hortensis Leach Cryptops anomalons lusitanus Verh. Scolopendra oraniensis Scolopendra oraniensis lusitanica Verh. Scolopendra cingulata (Latr.) Scolopendra subspinipes Leach Scutigera sp. Scutigera forceps (Raf.) Lithobius forficatus Linn. Lithobius coloradensis Cock. Lithobius calcaratus Koch Himantarium gabrielis Linn. Stigmatogaster gracilis Main. Himantarium gabrielis Linn. Lithobius forficatus Linn. Hirudinea sp. Silpha laevigata F. Galerita bicolor Drury Aeshna sp. Sciara sp. Dorcus paratielopipedus (L.) Order or Class Thysanura Myriapoda Coleoptera Neuroptera Orthoptera Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Crustacea Orthoptera Orthoptera Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Annelida Coleoptera Coleoptera Neuroptera Diptera Coleoptera 204 ILLINOIS BIOLOGICAL MONOGRAPHS [414 Parasite Host Order or Class crassus Leptochirus edax Sharp Coleoptera dicaeli Dicaelus ovalis Lee. Coleoptera digitatus Chlaenius vestitus (Payk.) Coleopterai dujardini Lithobius forficatus L. Myriapoda dytiscorum Dytiscus sp. Coleoptera fimbriatus Dissosteira Carolina L. Coleoptera gimbeli Harpalus pennsylvanicus Dej. Coleoptera harpali Harpalus caliginosus Fab. Coleoptera octacanthus Phryganea sp. Neuroptera repelini Phalangium sp. Arachnida sieboldi Agrion sp. Neuroptera stelliformis Ocypus olens (Mull.) Coleoptera Carabus auratus L. Coleoptera Carabus violaceus L. Rhizotrogus sp. striatus Scolopendra cingulata (Latr.) Myriapoda tipulae Tipida sp. Diptera zophus Nyctobates barbata Knoch Coleoptera Nyctobates pennsylvanica(dtGetr) Coleoptera sp. Ctenophora sp. Diptera Geniorhynchus aeschna Aeschna constricta Say Neuroptera monnieri Libellules sp. Neuroptera Phialoides ornator > Hydrophilus piceus (L.) Coleoptera Pyxinia crystalligera Dermestes vulpinus Fabr. Dermestes peruvianus Casteln. Coleoptera frenseli Attagenus pellio L. Coleoptera mobuszi Anthrenus verbasci Oliv.i Coleoptera rubecula Dermestes lardarius L. Coleoptera Dermestes vulpinus Fabr. Coleoptera Beloides firmus Dermestes lardarius L. Coleoptera tenuis Dermestes undulatus Brahm. Coleoptera Legeria agilis Colymbetes sp. Coleoptera Coleorhynchus heros Nepa sp. Hemiptera Bothriopsis histrio Dytiscus sp. Hydaticus cinereus L. Colymbetes fuscus L. Acilius sulcatus L. Coleoptera terpsichorella Hydrophilus sp. Coleoptera Asterophora cratoparis Cratoparis lunatus Fab. Neuroptera elegans Phryganea sp. Neuroptera mucronata Rhyacophila sp. Neuroptera philica Nyctobates pennsylvanica(.dtGttr) Coleoptera Schneideria mucronata Bibio sp. Diptera Stictospora provincialis Melolontha sp. Rhizotrogus sp. Coleoptera 415] STUDIES ON GREGARINES— WATSON 205 Parasite Stylocystis ensifera praecox Steinina harpali ohconica ovalis rotunda Taeniocystis truncata Amphoroides calverti polydesmi Pileocephalus bergi blaberae chinensis Anthorhynchus sophiae fissidens goronowitschi Sciadophora phalangii Hoplorhynchus actinotus scolopendras Amphorocephalus amphorellus ACANTHOSPORIDAE Acanthospora pileata polymorpha Corycella armata Ancyrophora gracilis uncmata Cometoides capitatus crinitus MENOSPORIDAE Menospora polyacantha STYLOCEPHALIDAE Stylocephalus balani brevirostris caudatus giganteus Host Leptochirus edax Sh. Tanypus sp. Harpalus pennsylvanicus longior (Kirby) Tribolium ferrugineum F. Tenebrio molitor L. Amara angustata Say Sericostoma Callipus lactarius (Say) Lysiopetalum lactarium (Say) Polydesmus complanatus (L.) Polydesmus dispar Silvestri Necrobia ruficolUs Fabr. Blabera clarasiana Sauss. Mystacides sp. Phalangida sp. Phalangides sp. Phalangium sp. Phalangium sp. Scolopocryptops sexspinosusiSzy) Scolopocryptops sp. Scolopendra woodi Mein. Scolopendra heros Giard Onto plus sp. Cistelides sp. Hydrous caraboides (L.) Gyrinus nataior (L.) Carabus sp. Carabus auratus L. Carabus violaceus L. Silpha thoracica L. Dytiscus sp. Calymbetes sp. Sericostoma sp. Limnophilus rhombicus (L.) Hydrous sp. Hydrobius sp. Order or Class Coleoptera Diptera Coleoptera Coleoptera Coleoptera Coleoptera Neuroptera Myriapoda Myriapoda. Myriapoda Myriapoda Coleoptera Orthoptera Neuroptera Arachnida Arachnida Arachnida Arachnida Myriapoda Myriapoda Myriapoda Coleoptera Neuroptera Coleoptera Coleoptera Coleoptera Agrion sp. Balanus sp. Hydrophilus sp. Phalangides sp. Eleodes sp. Eusattus sp. Coleoptera Coleoptera Neuroptera Coleoptera Coleoptera Neuroptera Crustacea Coleoptera Arachnida Coleoptera 206 ILLINOIS BIOLOGICAL MONOGRAPHS [416 Parasite Host Asida opaca Say Order or Class Asida sp. Coleoptera gladiator Helenophorus collaris L. Coleoptera heeri Phryganea sp. Neuroptera longicollis Blaps mortisaga L. Coleoptera oblongatus Opatrum sabulosum (L.) Asida grisea (F.) Coleoptera oligacanthus Agrion sp. Neuroptera phallusiae Phallusia sp. MoUusca sp. Xylopinus saperdioides Oliv. Coleoptera Sphaerorhynchus ophioides Acis sp. Coleoptera Lophocephalus insignis Helops striatus Geoflf. Coleoptera Cystocephalus algerianus Pimeiia sp. Coleoptera Oocephalus hispanus Morica sp. Coleoptera STENOPHORIDAE Stenophora aculeata Craspedosoma rawlinsii Verh. Myriapoda brolemanni Blaniulus hirsutus Brol. Myriapoda Brachyiulus superus Latzel Myriapoda Brachyiulus pusillus lusitanus Myriapoda Verh. chordeume Chordeuma silvestre C. Koch Myriapoda cockerellae Parajulus sp. Myriapoda Corsica Craspedosoma legeri Brol. Myriapoda dauphinia lulus mediterraneus Latzel Myriapoda Julus boleti C. Koch Myriapoda Julus fallax Meinert Myriapoda diplocorpa Euryurus erythropygus (Brandt) Myriapoda elongata Orthomorpha coarctata (Sauss.) Myriapoda fontariae Polydesmus sp. Myriapoda Fontaria sp. Myriapoda impressa Parajidus impressus (Say) Myriapoda jwH Julus sabulosus (L.) Myriapoda lulus fallax Mein. Myriapoda julipusilli Julus and Parajulus Myriapoda lactaria Callipus lactarius (Say) Myriapoda larvata Spirobolus spinigerus Wood Myriapoda nematoides Strongylosoma italicum Latz. Myriapoda polydesmi Fontaria virginiensis (Drury) Myriapoda polyxeni Polyxenus lagurus (L). Myriapoda producta Julus varius Fabricius Myriapoda robusta Parajulus venustus Wood Myriapoda Orthomorpha gracilis (C. Koch) Myriapoda Orthomorpha sp. Myriapoda silene Lysiopetalum foetidissimum Sav. Myriapoda spiroboli Spirobolus sp. Myriapoda varians Schizophyllum corsicum Brol. 417] STUDIES ON GREG ARINES— WATSON 207 GENERA OF UNCERTAIN POSITION Ulivina elliptica Audouinia sp. Annelida Ganymedes anaspidis Anaspides sp. Crustacea Nematoides fusiformis Balanus sp. Crustacea Agrippina bona Ceratophyllus fasciatus Bosk. Arachnida HOSTS WITH THEIK CEPHALINE GEEGARINE PAEASITES Host Group Acilius sulcatus L. Coleoptera Acts sp. Coleoptera Aeschna consiricta Say Neuroptera sp. Neuroptera Agrion sp. Neuroptera sp. Neuroptera sp. Neuroptera Allecula sp. Coleoptera Aiobates pennsylvanica deGeer Coleoptera Amara angustata Say Coleoptera Anaspides sp. Crustacea Anthrenus verbasci Oliv. Coleoptera Aphodius nitidulus F. Coleoptera prodromus (Brahm.) Coleoptera Arrhenoplita bicornis Oliv. Coleoptera Asida grisea (F.) Coleoptera opaca Say Coleoptera servillei Sol. Coleoptera sp. Coleoptera Astacus sp. Crustacea Attagenus pellio L. Coleoptera Atyaephyra desmaresti Crustacea Audouinia sp. Annelida Balanus improvisus Crustacea sp. Crustacea sp. Crustacea sp. Crustacea sp. Crustacea sp. Crustacea Bibio sp. Diptera Blabera cldraziana Sauss. Orthoptera Blaniulus hirsutus Brol. Myriapoda Blaps mortisaga L. Coleoptera Blattella germanica (L.) Orthoptera lapponica L. Orthoptera Boletophagus cornutus Panz. Coleoptera. Parasite Bothriopsis histrio Sphaerorhynchus ophioides Geniorhynchus aeschna Actinocephalus brachydactylus Menospora polyancatha Actinocephalus sieboldi Stylocephalus oligacanthus Gregarina tenuis Actinocephalus zophus Steinina rotunda Ganymedes anaspidis Pyxinia mobuszi Didymophyes leuckarti Didymophyes leuckarti Gregarina microcephala Stylocephalus oblongatus Stylocephalus giganteus Hirmocystis asidae Stylocephalus giganteus Gregarina miliaria Pyxinia frenseli Uradiophora cuenoti Ulivina elliptica Gregarina sp. (Solger) Gregarina sp. (Mawrodiadi) Gregarina sp. (KoUiker) Uradiophora communis Stylocephalus balani Nematoides fusiformis Schneideria mucronata Pileocephalus blaberae Stenophora brolemanni Stylocephalus longicollis Gregarina sp. (Gaede) Gregarina blattarum Gamocystis tenax Gregarina boletophagi 20S ILLINOIS BIOLOGICAL MONOGRAPHS [418 Host ■Brachyiulus superus Latz. pusillus lusitanus Verh. Brachystola magna Giard Callipus lactarius (Say) Cancer pagurus Carabus auratus L. violaceus L. sp. Ceratopkyllus fasciatus Bosk. Cetonia aurata L. Ceuthophilus latens Scud. maculatus (Say) stygius (Scud.) valgus Scud. Chlaenius vestitus (Payk.) Chordeuma silvestre C. Koch Chrysomela haemoptera L. violacea (Goeze) Cktamalus stellatus Cistelides sp. Coccinella novemnotata Herbst Coccinetta sp. sp. Colymbetes fuscus L. sp. sp. Coptotomus interrogatus (Fab.) Craspedosoma legeri rawlinsii Verh. Cratoparis lunatus Fab. Crypticus sp. Cryptops anomalons lusitanus Verh. hortensis. Leach Ctenophora sp. Cyphon pallidulus Boh. Dendarus iristis Rossi Dendrocoetum lacteum Dermestes lardarius L. peruvianus Casteln. Group Myriapoda Myriapoda Orthoptera Myriapoda Crustacea Coleoptera Coleoptera Coleoptera Arachnida Coleoptera Orthoptera Orthoptera Orthoptera Orthoptera Coleoptera Myriapoda Coleoptera Coleoptera Crustacea Neuroptera Coleoptera Coleoptera Coleoptera Coleoptera Coleoptera Coleoptera Coleoptera Myriapoda Myriapoda Coleoptera Coleoptera Myriapoda Myriapoda Diptera Coleoptera Coleoptera Platyhelminthes Coleoptera Coleoptera Parasite Stenophora brolemanni Stenophora brolemanni Gregarina rigida Amphoroides calverti Stenophora lactaria Frenzelina praemorsa •Actinocephalus stelliformis Ancyrophora gracilis Actinocephalus stelliformis Ancyrophora gracilis Ancyrophora gracilis Agrippina bona Gregarina curvata Gregarina longiducta Gregarina longiducta Gregarina sfygia Gregarina consobrina Actinocephalus digitatus Stenophora chordeume Gregarina munieri Gregarina munieri Frenzelina chtamali Acanthospora pileata Gregarina katherina Gregarina barbarara Gregarina fragilis Bothriopsis histrio Legeria agilis Ancyrophora uncinata Gregarina globosa Gregarina coptotomi Stenophora Corsica Stenophora aculeata Asterophora craptoparis Gregarina elongata Nina gracilis Dactylophorus robustus Actinocephalus sp. Sphaerocystis simplex Gregarina cavalierina Gregarina sp. (Hallez) Beloides firmus Pyxinia rubecula Pyxinia crystalligera 419] STUDIES ON GREGARINES— WATSON 209 Host undulatus Brahm. vulpinus Fabr. Dicaelus ovalis Lee. Dissosteira Carolina L. Dorcus parallelopipedus L. Dromia dromia Dytiscus sp. sp. sp. Elater sp. sp. Eleodes sp. Emhia sp. Encoptolophus sordidus (Burm.) Ephemera sp. sp. £ry^ oier Fab. Eupagurus prideauxi Euryurus erythropygus (Brandt) Eusattus sp. Font aria sp. virginiensis (Drury) Forficula auricularia L. Galerita bicolor Drury Gammarus pulex (L.) sp. sp. Geotrupes stercorarius (L.) Glomeris sp. Glossiphonia sp. Gryllomorpha dalmatina Ocsk. Gryllotalpa gryllotalpa (L.) sp. Gryllus abbrevtatus Serv. campestris L. domesticus L. Group Parasite Coleoptera Beloides tenuis Coleoptera Pyxinia crystalligera Pyxinia ruhecula Coleoptera Actinocephalus dicaeli Orthoptera Gregarina locustae Actinocephalus fimbriatus Coleoptera Actinocephalus conicus Crustacea Fremelina dromiae Coleoptera Actinocephalus dytiscorum Coleoptera Bothriopsis histrio Coleoptera Ancyrophora uncinata Coleoptera Gregarina elaterae Coleoptera Gregarina gracilis Coleoptera Stylocephalus giganteus Neuroptera Gregarina marteli Orthoptera Gregarina rigida Gregarina nigra Neuroptera Gamocystis ephemerae Neuroptera Gregarina granulosa Coleoptera Gregarina socialis Crustacea Frenzelina ocellata Myriapoda Stenophora diplocorpa Coleoptera Stylocephalus giganteus Myriapoda Stenophora fontariae Myriapoda Stenophora polydesmi Orthoptera Gregarina ovata Coleoptera Actinocephalus americanus Crustacea Didymophyes longissima Gregarina sp. (Pfeiffer) Crustacea Gregarina gamwari Crustacea Gregarina miliaria Coleoptera Didymophyes paradoxa Myriapoda Cnemidospora lutea Annelida Gregarina sp. (Bolsius) Orthoptera Gregarina davini Orthoptera Hirmocystis gryllotalpae Gregarina sphaerulosa Orthoptera Gregarina achetaeabbreviatae Gregarina galliveri Gregarina kingi Gregarina oviceps Leidyana erratica Orthoptera Gregarina oblonga Orthoptera Gregarina macrocephala Leidyana gryllorum 210 ILLINOIS BIOLOGICAL MONOGRAPHS [420 Host Group pennsylvanicus Burra. Orthoptera Gyrinus natator (L.) Coleoptera Harpalus caliginosus Fab. Coleoptera Harpalus pennsylvanicus Dej. Coleoptera pennsylvanicus longior (Kirby) Helenophorus collaris L. Helops striatus Geoff. Herpohdella sp. Hesperotettix pratensis Scudd. Himantarium gabrielis Linn. Hirudinea sp. Hydaiicus cinereus L. Hydrobius sp. Hydrophilus piceus (L.) sp. sp. Hydrous caraboides (L.) sp. Ischnoptera pennsylvanica (deGeer) Julus boleti C. Koch. fallax MeitJ. mediterraneus Latz. sabulosus (L.) varius Fab. sp. Lepisma saccharina L. Leptochirus edax Sharp Libellules sp. Libinia dubia Limnobia sp. Limnophilus rhombicus Lithobius calcaratus Koch coloradensis Cock. forficatus Linn. Coleoptera Coleoptera Coleoptera Annelida Orthoptera Myriapoda Annelida Coleoptera Coleoptera Coleoptera Coleoptera Coleoptera Coleoptera Coleoptera Orthoptera Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Myriapoda Thysanura Coleoptera Neuroptera Crustacea Diptera Neuroptera Myriapoda Myriapoda Myriapoda Parasite Leidyana erratica Corycella armata Actinocephalus harpali Gregarina parva Hirmocystis harpali Actinocephalus gimbeli Gregarina parva Steinina harpali Stylocephalus gladiator Lophocephalus insignis Gregarina sp. (Bolsius) Gregarina rigida Rhopalonia geophili Rhopalonia stella Metamera schubergi Bothriopsis histrio Cometoides crinitus Phialoides ornata Stylocephalus brevirostris Bothriopsis terpsichorella Acanthospora polymorpha Cometoides capitatus Gregarina iltinensis Stenophora dauphinia Stenophora juli Stenophora dauphinia Stenophora juli Stenophora dauphinia Stenophora juli Stenophora producta Stenophora julipusilli Gregarina lagenoides Actinocephalus crassus Stylo cystis ensifera Geniorhynchus monnieri Frenzelina olivia Hirmocystis polymorpha Ancyrophora uncinata Echinomera horrida Echinomera hispida Actinocephalus dujardini Acutispora macrocephala Echinomera hispida 421] STUDIES 'AT GREGARINl 'iS— WATSON Host Group Parasite Lucanus dama Thunb. Coleoptera Gregarina lucani Lysiopetalum foetidissimum Sav. Myriapoda Stenophora silene lactarium (Say) Myriapoda Amphoroides calverti Machilts cylindrica Geoff. Thysanura Hyalospora affinis Melolontha hrunnea Blanch. Coleoptera Gregarina melolonthae sp. Coleoptera Stictospora provincialis Melanoplus angustipennis (Dodge) Orthoptera Gregarina rigida atlantis (Riley) Gregarina rigida bivittatus (Say) Gregarina rigida coloradensis (Say) Gregarina rigida diff erentialis (Uhler) Gregarina rigida femoratus (B'urm.) Gregarina rigida femur-rubrum (deGeer) Gregarina rigida luridus (Dodge) Gregarina nigra Morica sp. Coleoptera Oocephalus hispanus Mystacida sp. Neuroptera Gregarina mystacidorum Mystacides sp. Neuroptera Pileocephalus chinensis Necrobia ruficollis Fabr. Coleoptera Pileocephalus bergi Nemobius sylvestris (F.) Orthoptera Gregarina macro cephala Nepa sp. Hemiptera Coleorhynchus heros Minus interstitialis Esch. Coleoptera Gregarina guatemalensis Nyctobates barbata Knoch Coleoptera Actinocephalus sophus pennsylvanica (deGeer) Coleoptera Actinocephalus zophus Asterophora philica Gregarina sp. (Crawley) Ocypus olens (Mull.) Coleoptera Actinocephalus stelliformis Oedipoda migratoria L. Orthoptera Gregarina oblonga stridula L. Orthoptera Gregarina oblonga Omoplus sp. Coleoptera Acanthospora pileata Opatrum sabulosum (L.) Coleoptera Stylocephalus oblongatus Orchesella villosa Thysanura Gregarina podurae Orchestia littorea Leach Crustacea Didymophyes longissima Orthomorpha coarctata \ (Sauss.) Myriapoda Stenophora elongata gracilis (C. Koch) Myriapoda Stenophora robusta sp. Myriapoda Stenophora robusta Oryctes nasicornis (L.) Coleoptera Didymophyes gigantea sp. Coleoptera Didymophyes gigantea Pachygraspus marmoratus Crustacea Frenselina conformis Pachyrhina sp. Diptera Hirmocystis ventricosa Pamphagus sp. Orthoptera Gregarina acridiorum Panchlora exoleta (Klug) Orthoptera Gregarina panchlorae 211 212 ILLINOIS BIOLOGICAL MONOGRAPHS [422 Host Group Parajulus impressus (Say) Myriapoda venustus Wood Myriapoda sp. Myriapoda sp. Myriapoda Parnus sp. Coleoptera Passalus cornutus Fab. Coleoptera Periplaneta americana (L.) Orthoptera orientalis (L.) Orthoptera Peripatus sp. Onycophora Perophora annectens Tunicata Petrobius maritimus Leach Thysanura Phalangida sp. Arachnida Phalangides sp. Arachnida sp. Arachnida Phalangium sp. Arachnida sp. Arachnida sp. Arachnida Phallusia sp. MoUusca Phronima sp. Crustacea Phryganea sp. Neuroptera sp. Neuroptera sp. Neuroptera Phyllognathus sp. Coleoptera Pimelia sp. Coleoptera Pinotheres pisum Crustacea Platycarcinus sp. Crustacea Platynus ruficollis Marsh. Coleoptera Poecilus cupreus (L.) Coleoptera PolUcipes sp. Crustacea Polydesmus complanatus (L.) Myriapoda dispar Silvestri Myriapoda sp. Myriapoda Polyxenus lagurus (L.) Myriapoda Portunus arcuaius Crustacea Psocus sp. Neuroptera Pterostichus stygkus (Say) Coleoptera Pterotrachea sp. MoUusca Reduvius personates L. Hemiptera Rhizotrogus aestivus Oliv. Coleoptera sp. Coleoptera Rhyacophila sp. Neuroptera Rhynchobolus amerkanus Annelida Parasite Stenophora impressa Stenophora robusta Stenophora cockerellae Stenophora julipusilli Gregarina laucournetensis Gregarina passali Gregarina blattarum Gregarina blattarum Gregarina serpentula Gregarina sp. (Moseley) Gregarina sp. (Ritter) Hyalospora roscoviana Anthorhynchus sophiae Anthorhynchus fissidens Stylocephalus caudatus Anthorhynchus gonorowitschi Sciadophora phalangii Actinocephalus repelini Stylocephalus phallusiae Gregarina clausi Actinocephalus octacanthus Asterophora elegans Stylocephalus heeri Didymophyes gigantea Cystocephalus algerianus Frenzelina fossor Gregarina praemorsa Gregarina platyni Gregarina amarae Gregarina valettei Amphoroides polydesmi Amphoroides polydesmi Stenophora fontariae Stenophora polyxeni Frenzelina portunidarum Gregarina psocorum Gregarina intestinalis Gregarina monarchia Gregarina pterotracheae Hyalospora reduvii Euspora fallax Actinocephalus stelliformis Stictospora provincialis Asterophora mucronata Gregarina sp. (Porter) 423] STUDIES ON GREGARINES— WATSON 213 Host Salpa aernginosa confoederata maxima vagina Scarabaeus relictus Sehistocerca americana Burm. paranensis Burm. Schizophyllum corsicum Brol. Sciara sp. Scolopendra cingulata (Latr.) heros Giard oraniensis oraniensis lusitanica Verb. suhspinipes Leach woodi Mein. Scolopocryptops sexspinosus (Say) sp. Scutigera forceps (Raf.) sp. Sericostoma sp. sp. Silpha laevigata F. thoracica L. Sphingonotus sp. Spirobolus sp. spinigerus Wood Statira unicolor Blanch. Stigmatogaster gracilis Mein. Strongylosomum italicum Latz. Talorchestia longicornis Tanypes sp. Tenehrio castaneus Knoch m alitor L. Tenebrionidae Termes sp. Thanasimus formicarius (L.) Timarcha tenebricosa (F.) Tipula sp. sp. sp. sp. Group Paeasite Tunicata Gregarina ensiformis Tunicata Gregarina fiava Tunicata Gregarina salpae Tunicata Gregarina flava Coleoptera Gregarina scarabaei Orthoptera Gregarina rigida Orthoptera Gregarina paranensis Myriapoda Stenophora varians Diptera Actinocephalus caudatus Myriapoda Nina gracilis Actinocephalus striatus Myriapoda Amphorocephalus amphorellus Myriapoda Nina giardi Myriapoda Nina giardi corsicum Myriapoda Nina indicia Myriapoda Hoplorhynchus scolopendras Myriapoda Hoplorhynchus actinotus Myriapoda Hoplorhynchus actinotus Myriapoda Trichorhynchus pulcher Myriapoda Trichorhynchus pulcher Neuroptera Taeniocystis truncata Coleoptera Ancyrophora uncinata Coleoptera Actinocephalus acutispora Ancyrophora gracilis Orthoptera Gregarina acridiorum Myriapoda Stenophora spiroboli Myriapoda Stenophora larvata Coleoptera Gregarina statirae Myriapoda Rhopalonia geophili Myriapoda Stenophora nematoides Crustacea Frenzelina delphinia Diptera Stylocystis praecox Coleoptera Gregarina grisea Coleoptera Gregarina cuneata Gregarina polymorpha Gregarina steini Steinina ovalis Coleoptera Gregarina tenebrionella. Neuroptera Gregarina termitis Coleoptera Gregarina longirostris Coleoptera Gregarina munieri Diptera Gregarina longa Diptera Gregarina tipula Diptera Hirmocystis ventricosa Diptera Actinocephalus tipulae 214 ILLINOIS BIOLOGICAL MONOGRAPHS [424 Host Group Tribolium ferrugineum F Coleoptera Tndactylus variegatus Latr. Orthoptera Trox perlatus Scriha. Coleoptera Tryxalis sp. Orthoptera Uca pugilat.or Crustacea pugnax Crustacea Udeopsylla nigra Locustidae Xylopmus saperdioides Oliv. Coleoptera Parasite Gregarina minuta Sfeinina obconica Didymophyes minuta Gregarina hyalocephak Gregarina acuta Gregarina acridiorum Frenzelina nigrofusca Frenzelina nigrofusca Gregarina udeopsyllae Stylocephalus sp. 425] STUDIES ON GREGARINES— WATSON 215 LIST OF NEW SPECIES PAGE ^Frenzelina delphinia 203, 213 ^Frenzelina nigrofusca _ 203, 213 ^Frenzelina oUvia 203, 210 *Gregarina iarbarara 184 Gregarina coptotomi 196 *Gregarina fragilis _ 185 *Gregarina galUveri Ill *Gregarina gloiosa _ _ 191 *Gregarina gracilis 188 *Gregarina illinensis 108 *Gregarina intestinalis 189 *Gregarina katherina 182 *Gregarina monarchia 190 *Gregarina nigra 116 Gregarina platyni 192 *Gregarina stygia 114 *Gregarina tenebrionella 187 Gregarina udeopsyllae 117 Hirmocystis harpali 168 Steinina harpali 155 *Steinina rotunda 154 *StenopUora diplocorpa 74 *Stenophora impressa 70 Stenophora lactaria - 72 * tDescribed in The Journal of Parasitology, 2:129-136. *A preliminary description was given in The Journal of Parasitology, 2:27-36. 216 ILLINOIS BIOLOGICAL MONOGRAPHS [426 BIBLIOGRAPHY Balbiani, G. 1889. Sur trois Entophytes nouveaux du tube digestif des Myriapodes. Jour. anat. physiol., 25:5-45; i pi. Berndt, a. 1902. Beitrag zur Kenntnis der im Darme der Larve von Tenebrio molitor lebenden Gregarinen. Arch. Protist, 1:375-420; 3 pi. Blanchard, L. F. 1905. Deux gregarines nouvelles parasites de Tenebrionides des maures. Ass. franc, pour I'avance't de sci. Comptes rendus, 33 :923-8. BOLLMAN, C. H. 1893. The Myriapoda of North America. Bull. U. S. Nat. Mus., 46 ; 210 pp. BUTSCHLI; O. 1881. Kleine Beitrage zur Kenntniss der Gregarinen. Zeit. f. wiss. Zool., 35:384-409; 2 pi. 1882. Gregarinida. Bronn's Klassen und Ordnungen des Thierreichs, vol. i, part i; pp. 503-589- Carus, J. V. and Gerstacher^ C. E. A. 1863. Handbuch der Zoologie, vol. 2. Crawley, H. 1902. The Progressive Movement of Gregarines. Proc. Acad. Nat. Sci. Phila., 54:4-20; 2 pi. 1903. List of Polycystid Gregarines of the United States. Proc. Acad. Nat. Sci. Phila., 5S:4i-S8; 3 pl- 1903a. The Polycystid Gregarines of the United States (Second Contribu- tion). Proc. Acad. Nat. Sci. Phila., 55:632-44; i pl. 1907. The Polycystid Gregarines of the United States (Third Contribu- tion). Proc. Acad. Nat. Sci. Phila., 59:220-8; i pl. CUENOT, L. 1895. fitudes physiologiques sur les Orthopteres. Arch, biol., 14:293-341; 2 pl. 1897. Evolution des gregarines coelomiques du grillon domestique. C. R. acad sci. Paris, 125 :S2-4. 1901. Recherches sur devolution et la conjugaison des gregarines. Arch. biol., l7:58l-6'52; 4 pl. Delage, Y. and Herouard, E. 1896. Traite de zoologie concrete. Introduction and Protozoa; vol. i; 584pp. Desmasest, 1845. D'Orbigny's Dictionaire d'histoire naturelle, vol. 6. [Quoted from Diesing, 1851.] 427] STUDIES ON GREGARINES— WATSON 217 DiESING, K. M. 1851. Systema helminthum, vol. 2. Vindobonae, 591 pp. 1859. Revision des Rhyngodeen. Sitzb. Kais. Akad. Wiss., Wien, math natw. KL, 37:719-82; 3 pi. DUFOUR, L. 1826. Recherches anatoniique sur les carabiques et plusieures autres insects Coleopteres. Ann. sci. nat., (i) 8:42-45; i pi. 1828. Note sur la gregarine nouveau genre de ver qui vit en tropeau de la intestine de divers insects. Ann. sci. nat.j (i) 13:366-7. 1837. Recherches sur quelque entozoaires et larves parasites des insects Orthopteres et Hymenopteres. Ann. sci. nat., (2) 7:3-20; i pi. Ellis, M. M. 1912. A New Species of Polycystid Gregarine from the United States. Zool. Anz., 39:25-7. 1912a. Five Polycystid Gregarines from Guatemala. Zool. Anz., 39 :68o-9. 1912b. A New Species of Gregarine from North American Diplopods. Zool. Anz., 40:8-11. 1913. New Gregarines from the United States. Zool. Anz., 41 :462-5. 1913a. Three Gregarines from Louisiana. Zool. Anz., 42:200-2. 1913b. A Descriptive List of the Cephaline Gregarines of the New World. Trans. Amer. Micr. Soc, 32 :2Sg-g6 ; 4 pi. 1913c. Gregarines from some Michigan Orthoptera. Zool. Anz., 43 :78-84. Feantzius, a. von 1848. Einige nachtragliche Bemerkungen iiber Gregarinen. Arch. Naturg., 14:188-96; I pi. Frenzel, J. 1892. Uber einige argentinische Gregarinen. Jen. Zeitschr., 27:233-336; ipl. Gabriel, B. 1880. Zur Classification der Gregarinen. Zool. Anz., 3 :56g-72. Gaede, H. M. 1815. Beytrage zur Anatomic der Insekten. Altona. Grebnecki, '. 1873. Mem. Soc. Nat. Nouvelle-Russie. Odessa. [Quoted from Sokolow, 191 1.] Hall, M. C. 1907. A Study of some Gregarines with Especial Reference to Hirmocystis rigida, n. sp. Univ. Nebr. Studies, 7:149-74; i pi. Hammerschmidt, K. E. 1838. Helminthologische Beytrage. Isis (Oken), (5) 351-8, 4 pi. [Quoted from Stein, 1848.] Huxley, J. 1910. On Ganymedes anaspidis (n. g.,, n. s.) a Gregarine from the Digestive Tract of Anaspides tasmaniae (Thompson). Quar. Jour. Micr. Sci., SS :i55-7S- ISHII, S. 1911. On the Intracellular Stage of Gregarina polymorpha. Ann. Zool. Japon., 7 :279-84. 218 ILLINOIS BIOLOGICAL MONOGRAPHS [428 1914. On Four Polycystid Gregarines from the Intestine of Tribolium ferrugineum F. Ann. Zool. Japon., 8:435-41. KOLLIKER, A. 1848. Beitrage zur Kenntniss niederer Thiere. Zeit. f. wiss. Zool., 1:1-37; 3 pl. KUNCKEL d'HeRCULAIS, J. 1899. De la mue chez les insectes consideree comma moyen de defense centre les parasites vegetaux ou animaux. C. R. acad. sci. Paris, 128:620-2. Labbe, a. 1899. Sporozoa. Das Tierreich, pt. 5; 196 pp. Lankester, E. R. 1863. On Our Present Knowledge of the Gregarinidae. Quar. Jour. Micr, Sci., 3:83-96. LatzeLj R. 1884. Die Myriapoden der Osterreichisch-Ungarischen Monarchic. Wien; 414 PP-. 16 pl. Laveran, a. and Mesnil, F. 1900. Sur quejlques particularites de I'evolution d'une gregarine et la reaction de la cellule-hote. C. R. soc. biol., 52:554-7. Leger, L. 1892. Recherches sur les gregarines. Tabl. zool., 3 :i-i83 ; 22 pl. 1893a. Sur une gregarine nouvelle des Acridiens d'Algerie. C. R. acad. sci. Paris, 117:811-813. 1894. Sur une nouvelle gregarine de les famille des Dactylophorides para- site des geophiles. C. R. acad. sci. Paris, 118:1285-8. 1896. Nouvelles recherches sur les polycystidees parasites des arthropodes terrestres. Ann. fac. sci. Marseille, 6; 54 pp., 2 pl. 1899. Quelques types nouveaux de dactylophorides de la region mediter- raneene. Trav. stat. zool. Wimereux, 7 :390-5 ; i pl. [Quoted from Sokolow, 1899.] 1906. fitude sur Taeniocystis mira Leger, Gregarine metamerique. Arch. Protistenk., 7 :307-329 ; i pl. Leger^ L. and Duboscq, O. 1899. Notes biologiques sur les grillons. Arch. zool. exper., (3) 7:35-40. 1900. Les gregarines et I'epithelium intestinal. C. R. acad. sci. Paris, 130:1566-8. 1902. Les gregarines et I'epithelium intestinal chez les tracheates. Arch, parasit, 6:377-473; S ph 1903. Note sur le developpement des gregarines stylorhynchides et ste- nophorides. Arch. zool. exper., (4) i :89-9S. 1903a. Recherches sur les myriapodes de Corse et leurs parasites. Arch, zool. exper., (4) i :307-58. 1904. Nouvelles recherches sur les gregarines et I'epithelium intestinal des tracheates. Arch. Protist, 4:335-83; 2 pl. 1907. L'evolution des Frenzelina n.g. C. R. acad. sci. Pan's, 145:773-4- 1909. fitudes sur la sexualite chez les gregarines. Arch. Protist. 17:19-134; SPI. 429] STUDIES ON GREGARINES— WATSON 219 Leidy, J. 1849. New Genera and Species of Entozoa. Proc. Acad. Nat. Sci. Phila., 4:231-3- 1851. Contributions to Helminthology. Proc. Acad. Nat. Sci. Phila., 5:205- 209. 1851a. Corrections and Additions to Former Papers on Helminthology Pub- lished in the Proceedings of the Academy. Proc. Acad. Nat. Sci. Phila., S ■.284-2Q0. 1853. On the Organization of the Genus Gregarina of Dufour. Trans. Amer. Phil. Soc., n.s., 10:233-40; 2 pi. 1856. A Synopsis of Entozoa. Proc. Acad. Nat. Sci. Phila., 8:42-58. i88g. On Several Gregarines and a Singular Mode of Conjugation of One of Them. Proc. Acad. Nat. Sci. Phila., 1889:9-11. Leuckart, R. 1879. Die Parasiten des Menschen und die von ihnen herriihrenden Krank- heiten, Ed. 2, vol. i. Magalhaes, p. S. de 1900. Notes d'helminthologie bresilienne. Arch, parasit., 3:34-69. Marshall, W. S. 1893. Beitrage zur Kenntnis der Gregarinen. Arch. Naturg., 59:25-44; i pi. Mawrodiadi, ? 1908. Memoires soc. nat. Nouvelle-Russie, Odessa, 32:101-33. [Quoted from Sokolow, igii.] Merciee, L. 1912. Monographic d'Uradiophora cuenoti. Arch. zool. exper., (5) 10:177- 202; 2 pi. Merton, H. 1911. Eine neue Gregarine (Nina indicia n. sp.) aus dem Darni von Scolo- pendra subspinipes Leach. Abh. Senckenberg. Nat. Ges. Frankfurt-a-M., 34:119-26; I pi. MiNGAZZINI, P 1889. Contribution alia conoscenza delle gregarine. Atti Ace. Lincei, rend., (4) 4:234-9- 1889a. Ricerche sulle Didymophyidae. Atti Ace. Lincei, rend., (4) 5 :365-8. 1891. Gregarine monocistidee, nuove o poco conosciute, del Golfo di Napoli. Atti Ace. Lincei, rend., (4) 7 :467-74- Paehler^ Fr. 1904. Uber die Morphologie, Fortpflanzung und Entwicklung von Gregarina ovata. Arch. Protist., 4:64-87; 2 pi. Pfeiffer, E. 1910. Untersuchungen iiber die Gregarinen im Darm der Larve von Tenebrio molitor. Arch. Protist., 19:107-18. Pfeiffer, L. 1893. Untersuchungen iiber den Krebs. Jena, 1893. [Quoted from Labbe, 1899.] POCHE, F. 1913. Das System der Protozoa. Arch. Protist., 30:125-321. 220 ILLINOIS BIOLOGICAL MONOGRAPHS [430 Porter, J. F. 1897. Two New Gregarinidae. Jour. Morph., 14:1-20; 3 pi. SCHEWIAKOFF, W. 1894. Uber die Ursache der fortschreitenden Bewegung der Gregarinen. Zeit. f. wiss. Zool., 58:340-54; 2 pi. Schneider, A. 1873. Sur quelques points de I'histoire du genre Gregarina. Arch. zool. exper., 2:515-33; i pi. 1875. Contributions a I'histoire des gregarines des invertebres de Paris et de Roscoff. Arch. zool. exper., 4:493-604; 7. pi. 1882. Seconde contribution a I'etude des gregarines. Arch. zool. exper., 10:423-50; I pi. 1884. Sur le developpement du Stylorhynchus longicollis. Arch. zool. exper., (2) 2:1-36; I pi. 1885. fitudes sur les developpement des gregarines. Tabl. zool., i : 10-24; 6 pi. l88sa. Gregarines nouvelles ou peu connues. Tabl. zool., i :25-30 ; 2 pi. 1886. Gregarines nouvelles ou peu connues. Tabl. zool., i :90-i03 ; 6 pi. 1887. Gregarines nouvelles ou peu connues. Tabl. zool., 2 :67-85 ; i pi. SCHNITZLER, H. 1905. Uber die Fortpflanzung von Clepsidrina ovata. Arch. Protist., 6:309- 33; 2 pi. SlEBOLD, C. E. VON 1837. Fernere Beobachtungen iiber die Spermatozoen der wirbellosen Thiere. Arch. Anat. Physiol. Med., 1837:381-439. 1839. Beitrage zur Naturgeschichte der wirbellosen Thiere. Neuest. Schrift. d. Naturf. Gesell., Danzig, 3 :56-7i ; i pi. [Quoted from Diesing, 1851.] SOKOLOW, B. 191 1. Liste des Gregarines decrites depuis 1899. Zool. Anz., 38:277-95. Stein, F. 1848. t)ber die Natur der Gregarinen. Arch. Anat. Physiol. Med., 1848; 182-223; I pl- Strickland, C. 1912. Agrippina bona, n.g., et n. sp., representing a New Family of Gre- garines. Parasitology, 5:97-108; i pi. Wasielewski, Th. von 1896. Sporozoenkunde. Jena, 162 pp. Watson, M. E. 1915. Some New Gregarine Parasites from Arthropoda. Jour. Parasit., 2:27-36; 2 pi. 1916. Three New Gregarines from Marine Crustacea. Jour. Parasit., 2:129- 36; I pi. WOLTERS, M. 1891. Die Conjugation und Sporenbildung bei Gregarinen. Arch. mikr. Anat., 37:99-138; 4Pl- 431] STUDIES ON GREGARINES— WATSON 221 EXPLANATIONS OF PLATES All original drawings were made with the camera lucida directly from the live material and the magnification of each is given. All the drawings which were copied from other authors were drawn by means of the camera lucida and the source of each drawing is given in the explanation of the individual plates. No magnifications are men- tioned in the majority of the original sources and hence none can be given here. 222 ILLINOIS BIOLOGICAL MONOGRAPHS [432 EXPLANATION OF PLATE Fig. I. Stenophora larvata (Leidy) Ellis. After Leidy, 1853, Plate X, Fig. i. Figs. 2, 3, 4. Stenophora polydesnii (Lankester) Watson. After Leidy, 1853, Plate XI, Figs. 23, 25, 27. Fig. 5. Stenophora julipusilli (Labbe) Crawley. After Leidy, 1853, Plate X, Fig. 21. Fig. 6. Stenophora julipusilli (Labbe) Crawley. After Crawley, 1903a, Plate XXX, Fig. 17. Fig. 7. Stenophora juli (Frantzius) Labbe. After Frantzius, 1848, Plate VII, x. Fig. 1. Fig. 8. Stenophora juli (Frantzius) Labbe. After Schneider, 1875, Plate XX, Fig. 29. Fig. 9. Stenophora dauphinia Watson. After Leger and Duboscq, 1904, Plate XIV, Fig. 13. Fig. 10. Stenophora spiroboli Crawley. After Crawley, 1903, Plate II, Fig. 22. Figs. II, 12. Stenophora foniariae (Crawley) Watson. After Crawley, 1903, Plate I, Fig. 12; Fig. 14. Fig. 13. Stenophora brolemanni Leger and Duboscq. After Leger and Duboscq, igo3a. Fig. 21. Figs. 14, 15. Stenophora nematoides Leger and Duboscq. After Leger and Du- boscq, 1903a, Fig. 17(2), Fig. 17(1). Figs. 16, 17. Stenophora varians Leger and Dubosq. After Leger and Duboscq, 1903a, elongate form Fig. 18; globose form Fig. 20. Fig. 18. Stenophora producta Leger and Duboscq. After Leger and Duboscq, 1904, Plate 14, Fig. 10. , Figs. 19, 20. Stenophora aculeata Leger and Duboscq. After Leger and Duboscq, 1904, Plate 14, Fig. S ; protomerite Fig. 14. Fig. 21. Stenophora polyxeni Leger and Duboscq. After Leger and Duboscq, 1904, Plate 14, Fig. 6. Figs. 22, 23. Stenophora silene Leger and Duboscq. After Leger and Duboscq, 1904, Plate 14, elongate form Fig. 12b; globose form Fig. 12a. Figs. 24, 25. Stenophora chordeume Leger and Duboscq. After Leger and Du- boscq, 1904, Plate 14, globose form Fig. 11; elongate form Fig. 15. Fig. 26. Stenophora robusta Ellis. After Ellis, 1912b, Fig. lb. Fig. 27. Stenophora cockerellae Ellis. After Ellis, 1912a, Fig. ic. mi \A s^ ,ji%i. ■#^s. "'■&f2 m ■■'"Sc:;| ixO /4 ^^ii;;g-'6 ..-S- ■■%:,■. -^ ' '"sj^ rv 12 •i^-*. 3^iSw ■.■.■..' ^& /e© ■■> - ,- ■: tiS' ■;■. •;.:■■■ .■■■•■-•■•■• ■•g.- ,• IS* .vfeix' '* -^ ■''•:•>■//■■ • ■• 'i '■:■' -iSf ^■■' ■SS* ■;•'■■•, ii Ml io '17 SO ■%:;;,■;/.■■■;••)-;:;;; 1li:WP-^-*-^^- :v /^^^ mifm. mm 24 '22 ':-j23 ;:■■ \ PLATE J V.,..v:'>',5e ^7- 18 433] STUDIES ON GREGARINES— WATSON 223S PLATE II 224 ILLINOIS BIOLOGICAL MONOGRAPHS [434 EXPLANATION OF PLATE Fig. 28. Stenophora elongata Ellis. After Ellis, igi2a, Fig. 4n. Fig. 29. Dactylophorus robustus Leger. After Labbe, 1899, Fig. 27. Fig. 30. Nina gracilis Grebnecki. After Labbe, 1899, Fig. 24. Fig. 31. Nina giardi corsicum (Leger and Duboscq) Sokolow. After Leger and Duboscq, 1903a, Fig. 15. Fig. 32. Echinomera hispida (Schneider) Labbe. After Schneider, 1875, Plate XVI, Fig. 36. Fig. 33. Nina indicia Merton. After Merton, 191 1, Plate III, Fig. i. Fig. 34. Acutispora macrocephala Crawley. After Crawley, 1903a, Plate XXX, Fig. I. Fig. 35. Trichorhynchus pulcher Schneider. After Leidy, 1889, Fig. 3. Fig. 26. Trichorhynchus pulcher Schneider. After Schneider, 1882, Plate XIII, Fig. 14. Fig. 37. Actinocephalus striatus Leger and Duboscq. After Leger and Duboscq, 1903a, Fig. 16. Figs. 38, 39, 40. Actinocephalus dujardini Schneider. After Schneider, 1875, Plate XVI, Fig. 9; Fig. 10; Fig. 12. Fig. 41. Hoplorhynchus scolopendras Crawley. After Crawley, 1903a, Plate XXX, Fig. 19. Figs. 42, 43. Hoplorhynchus acHnotus (Leidy) Crawley. After Crawley, 1903, Plate III, Fig. 37; Leidy, 1889, Fig. 2. Fig. 44. Trichorhynchus lithobii Crawley. After Crawley, 1903a, Plate XXX, Fig. 18. Figs. 45, 46. Amphorocephalus amphorellus Ellis. After Ellis, 1913, Fig. i ; Fig. 2. Fig. 47. Species of uncertain genus. After Balbiani, 1889, Plate II, Fig. 34. Fig. 48. Species of uncertain genus. After Kolliker, 1848, Plate III, Fig. 30. Figs. 49, so. Nina gracilis Grebnecki, in section. After Leger and Duboscq, 1902, Plate VI, Fig. 93; Fig. 96. Fig. 51. Rhopalonia geophili Leger. After Labbe, 1899, Fig. 21. 1 tt 'Q] .;??%'• '-'^M^- ^m!^:^'"'"^^^' ■%r #29 /: 28 ■-,/ 30 i\ ;-,-.'| '■■'sx i:.* 32 M "'48. 34 135 41 3e : 37 '■<■' 38 40 ? 4d ■■' m 45 ,-,,rri'fvrVnf,^.i 42 'tmM J 44 PLATE II ■TO J"4r \$^4»- ■435] STUDIES ON GREGARINES— WATSON 225 PLATE III 226 ILLINOIS BIOLOGICAL MONOGRAPHS [436 EXPLANATION OF PLATE Fig. 52. Amporoides calverti (Crawley) Watson., X 195. Fig. S3. Stenophora impressa Watson, X 195. Fig. 54. Stenophora diplocorpa Watson, X 195. Fig. 55. Stenophora lactaria Watson, X i9S. Figs. 56, 57. Cnemidospora lutea Schneider. After Schneider, 1882, Plate XIII, Fig. 44; protomerite, Fig. 44. Fig. 58. Amphoroides polydesmi (Leger) Labbe. After Leger, 1892, Plate X, Fig. 10. Figs. 59, 60. Didyniophyes leuckarti Marshall. After Marshall, 1893, Plate II, Fig. 24; Fig. 26. Didymophyes gigantea Stein. After Stein, 1848, Plate XI, Fig. 40. Didymophyes paradoxa Stein. After Leger, 1892, Plate VI, Fig. 14. Didymophyes gigantea Stein. After Labbe, 1889, Fig. 4. Actinocephalus americanus Crawley. After Crawley, 1903a, Plate XXX, Fig. 22. Stylocephalus sp. After Crawley, 1903, Plate III, Fig. 29. Actinocephalus digitatus Schneider. After Schneider, 1875, Plate XVI, Fig. 3S. Actinocephalus stelliformis Schneider. After Schneider, 1875, Plate XVI, Fig. 32. Actinocephalus crassus (Ellis). After Ellis, 1912a, Fig. 7. "Actinocephalus stelliformis Schneider. After Schneider, 1875, Plate XVI, Fig. 32. Actinocephalus harpali Crawley. After Crawley, 1903, Plate I, Fig. i. Didymophyes minuta (Ishii) Watson. After Ishii, 1914, Fig. 2a. Didymophyes paradoxa Stein. After Stein, Plate IX, Fig. 34. Actinocephalus stelliformis Schneider. After Schneider, 1875, Plate XX, Fig. 20. Fig. 74. Actinocephalus zophus (Ellis). After Ellis, 1913a, Fig. 2. Fig. 61. Fig. 62. Fig. 63. Fig. 64. Fig. 65. Fig. 66. Fig. 67. Fig. 68. Fig. 69. Fig. 70. Fig. 71- Fig. 72. Fig. 73- rN J,... 58 56 5» '5i S3 ill 1 1 ' ': T * *" / 4. \ 55 57 /-" 63 ••• 64 , 65 5:J 60 1 J ^ c 67 iff:! IS// i\ w: tups? V, PLATE III ^^^i^' -•'••■■f. ■^^ i' «• ? e 90: f/^ \ \ M V3i, ^'9f> ^/a7 •;©? ^J 79 So 93 94 JOJ 80 vmrnrMjflf 86 PLATE IV ;ra2 IM:& was 95 J9S 103 «• 104 IQS ■• 439] STUDIES ON GREG ARINES— WATSON 229 ^ PLATE V 230 ILLINOIS BIOLOGICAL MONOGRAPHS [440 EXPLANATION OF PLATE Fig. io6. Stylocephalus oblongatus (Hammerschmidt) Watson. After Schneider, 1875, Plate XVin, Fig. 3. Fig. 107. Stylocephalus longicollis (Stein) Watson. After Schneider, 1875, Plate XIX, Fig. I. Figs. 108, 109. Stylocephalus giganteus Ellis. After Ellis, 1912, Fig. 2; Fig. id. Fig. no. Lophocephalus insignis (Schneider) Labbe. After Schneider, 1882, Plate XIII, Fig. I. Figs. Ill, 112. Corycella armata Leger. After Leger, 1892, Plate XVI, Fig. 7; Fig. 8. Fig. 113. Asterophora philica (Leidy) Crawley. After Leidy, 1889, Fig. 7. Fig. 114. Lophocephalus insignis (Schneider) Labbe. After Wasielewski, 1896, Fig. S. Fig. 115. Cystocephalus algerianus Schneider, cephalont. After Labbe, 1899, Fig. 82. Fig. 116. Beloides firmus (Leger) Labbe. After Labbe, 1899, Fig. 64. Fig. 117. Beloides tenuis (Leger) Labbe. After Labbe, 1899, Fig. 65. Fig. 118. Stylocephalus brevirostris (Kolliker) Watson. After Kolliker, 1848, Plate II, Fig. 14. Fig. iig. Pyxinia rubecula Hammerschmidt. After Frantzius, 1848, Plate VII, Group II, Fig. I. Fig 120. Stylocephalus oblongatus (Hammerschmidt) Watson. After Schneider, 187s, Plate XVIII, Fig. 5- Fig. 121. Stylocephalus longicollis (Stein) Watson. After Schneider, 1875, Plate XIX, Fig. 2. Fig. 122. Ancyrophora gracilis Leger. After Leger, 1892, Plate XIX, Fig. 11. Figs. 123, 124. Cometoides capitatus (Leger) Labbe. After Leger, 1892, Plate XVI, Fig. 3; Fig. 4. Fig. 125. Cometoides crinitus (Leger) Labbe. After Leger, 1892, Plate XVIII, Fig. 3. Figs. 126, 127. Actinocephalus gimbeli (Ellis) Watson. After Ellis, 1913, Fig. 4. Fig. 3. Fig, 128. Epimerite of Gregarina munieri (Schneider) Labbe. After Schneider, 187s, Plate XVIL Fig. 2. 1. ^iK... 108 ¥ Ul 109 \§ii;;Pl x'lor \-(aKh06-.c-^^--^:r^-»,, ■: WAp:^SM0'^^' 115 W^Jiio '■ m. ■■'.:': .>?. . ■ 116 117 m ''^lUsti y;/ ii8 120 -■ 125 119. M 127 J22. izs Wi • .m3 PLATE V 124 ■i28 441] STUDIES ON GREG ARINES— WATSON 231 PLATE VI 232 ILLINOIS BIOLOGICAL MONOGRAPHS [442 EXPLANATION OF PLATE Fig. 129. Hyalospora roscoviana Schneider. After Schneider, 1875, Plate XVI, Fig. 41. Fig. 130. Gregarina parva (Crawley) Watson. After Crawley, 1903a, Plate XXX, Fig. 10. Fig. 131. Euspora fallax Schneider. After Schneider, 1875, Plate XVIII, Fig. 14. Figs. 132, 133, 134, 13s, 136. Gregarina cuneata Stein. After Schneider, 1875, Plate XX, Fig. 11; Stein, 1848, Plate IX, Fig. 23; Crawley, 1903, Plate III, Fig. 30; Frantzius, 1848, Plate VII, Group V, Fig. i; Ishii, 1914, Fig. I. Fig. 137. Sphaerocystis simplex Leger. After Leger, 1892, Plate VI, Fig. 11. Fig. 138. Gregarina statirae Frenzel. After Frenzel, i892,Plate VIII, Fig. I. Fig. 139. Gregarina passali Lankester. After Crawley, 1903, Plate II, Fig. 24. Figs. 140, 141, 142. Gregarina polymorpha (Hammerschmidt) Stein. After Frant- zius, 184S, Plate VII, Group V, Fig. 2; Schneider, 1875, Plate XX, Fig. 10; Stein, 1848, Plate IX, Fig. 24. Fig. 143. Gregarina minuta Ishii. After Ishii, 1914, Fig. 2b. Fig. 144. Gregarina guatemalensis Ellis. After Ellis, 1912a, Fig. 6t. Fig. 145. Uncertain species (.Gregarina holetophagi Crawley). After Crawley, 1903, Plate II, Fig. 26. Fig. 146. Gregarina steini Berndt. After Berndt, 1902, Plate XIII, Fig. 69. Fig. 147. Gregarina munieri (Schneider) Labbe. After Schneider, 1875, Plate XVII, Fig. I. Fig. 148. Actinocephalus dytiscorum (Frantzius) Watson. After Frantzius, 1848,. Plate VII, Group VII, Fig. i. Fig. 149. Uncertain species {Gregarina microcephala Leidy). After Leidy, 1889, Fig. 4- Miill iA m^ l^ji^i 129 \ W» \ A 135 13.3 ''"iMvSh :i3X W&$ '''-■< iSS) M' 130 0^^. 132 I P' 139 140 .^^^mM M^l \ .V is'r 138 ''^^ Ifffilil' mm -.,i{l43. N;::2l::;:..'..'----j^4 i45 '^146 PLATE VI "^-'■'147 ^149i 443] STUDIES ON GREGARINES— WATSON 233 PLATE VII 234 ILLINOIS BIOLOGICAL MONOGRAPHS [444 EXPLANATION OF PLATE Fig. ISO. Gregarina lucani (Crawley) Watson. After Crawley, 1903, Plate III, Fig. 38. Fig. 151. Gregarina grisea Ellis. After Ellis, 1913a, Fig. i. Fig. 152. Gregarina cuneata Stein. After Leger and Duboscq, 1904, Fig. 5. Fig. 153. Gregarina polymorpha (Hammerschmidt) Stein. After Leger and Du- boscq, 1904, Fig. 6. Fig. 154. Gregarina elongate Frantzius. After Frantzius, 1848, Plate VII, Group IV, Fig. 2. Fig. 155. Gregarina longirostris (Leger) Labbe. After Leger, 1892, Plate XI, Fig. S- Figs. 156, 157. Uncertain species (Gregarina ovalis (Crawley) Watson). After Crawley, 1903, Plate I, Fig. S ; Fig. 6. Fig. 158. Uncertain species {Gregarina elaterae Crawley). After Crawley, 1903, Plate I, Fig. 11. Fig. 159. Pyxinia rubecula Hammerschmidt. After Leger, 1892, Plate XIV, Fig. 2. Fig. 160. Spore of Cystocephalus algerianus Schneider. After Labbe, 1899, Fig. 8. Fig. 161. Spores of Lophocephalus insignis (Schneider) Labbe. After Schneider, 1882, Plate XIII, Figs. 48, So. Fig. 162. Spore of Acanthospora pileata Leger. After Leger, 1892, Plate XV, Fig. sa. Fig. 163. Spore of Acanthospora polymorpha Leger. After Labbe, 1899, Fig. 68. Fig. 164. Spore of Ancyrophora gracilis Leger. After Leger, 1892, Plate XIX, Fig. 12b. Fig. 165. Spore of Cometoides capitatus (Leger) Labbe. After Leger, 1892, Plate XVI, Fig. S- Fig. 166. Spore of Corycella armata Leger. After Leger, 1892, Plate XVI, Fig. 10. Fig. 167. Gregarina monarchia Watson, X 60. Fig. 168. Gregarina intestinalis Watson, X 190. Fig. 169. Gregarina barbarara Watson, X 24s. Fig. 170. Gregarina gracilis Watson, X 195. Fig. 171. Gregarina katherina Watson, X 245. Fig. 172. Gregarina coptotomi Watson, X 19s. Fig. 173. Steinina rotunda Watson, X 195. Fig. 174. Gregarina tenebrionella Watson, X 195. Fig. 175. Gregarina fragilis Watson, X i9S- m I i 152 J}3 W50 167 108 16Sf lU 155 iy6 1j9 17Z 100 101 171 ■■■^.157- W8. IfiZ lO-'h '.»■ 'XH 170 PLATE VII 174 ■1T3 jM 445] STUDIES ON GREGARINES— WATSON 235 PLATE VIII 236 ILLINOIS BIOLOGICAL MONOGRAPHS [446 EXPLANATION OF PLATE Fig. 176. Gregarina globosa Watson, X 100. Figs. 177, 178. Gregarina ohlonga Dufour. After Dufour, 1837, Plate I, Fig. 9; Fig. pa. Fig. 179. Cysts of species called by Dufour G. sphaerulosa. After Dufour, 1837, Plate I, Fig. 4. Fig. 180. Cysts of species called by Dufour G. soror. After Dufour, 1837, Plate I, Fig. 5. Figs. 181, 182. Gregarina hyalocephala Dufour. After Dufour, 1837, Plate I, Fig. 8; Fig. 8a. Fig. 183. Gregarina ovata Dufour. After Frantzius, 1848, Plate VII, Group IX, Fig. I. Fig. 184. Gregarina blattarum Siebold. After Schneider, 1875, Plate XVII, Fig. 11. Figs. 18s, 186. Gregarina serpentula deMagalhaes. After deMagalhaes, 1900, Fig. 4. Fig. 187. Gregarina panchlorae Frenzel. After Frenzel, 1892, Plate VIII, Fig. 20. Fig. 188. Gregarina locustae Lankester. After Leidy, 1853, Plate XI, Fig. 35. Figs. 189, 190. Actinocephalus fimbriatus (Diesing) Ellis. After Leidy, 1853, Plate XI, Fig. 37; Crawley, 1907, Plate XVIII, Fig. 3. Figs. 191, 192. Gregarina oviceps Diesing. After Leidy, 1853, Plate XI, Fig. 32; Crawley, 1903, Plate III, Fig. 35. Fig. 193. Gregarina kingi Crawley. After Crawley, 1907, Plate XVIII, Fig. 10. Fig. 194. Gregarina rigida (Hall) Ellis. After Crawley, 1907, Plate XVIII, Fig. 8. Fig. 195. Gregarina longiducta Ellis. After Ellis, 1913c, Fig. 8. Fig. 196. Gregarina consobrina Ellis. After Ellis, 1913b, Plate XVIII, Fig. 24. Figs. 197, 198. Gregarina rigida (Hall) Ellis. After Hall, 1907, Plate I, Fig. 8; Watson, 191S, Plate II, Fig. 19. Fig. 199. 'Gregarina macrocephala (Schneider) Labbe. After Schneider, 1882, Plate XIII, Fig. 42. Fig. 200. Hyalospora affinis Schneider. After Schneider, 1882, Plate XIII, Fig. 33- Fig. 201. Gamocystis tenax Schneider. After Schneider, 187S, Plate XIX, Fig. 10. Fig. 202. Pileocephalus blaberae (Frenzel) Labbe. After Frenzel, 1892, Plate VIII, Fig. 24. r , -176 7/7 , ns J 79 -180 18/ 1S2 J90 183, % '.isi 187 188 189 101 186 190 197 192 183 ■safsa; 195 fe .-■' . ■ -202 199] 201 PLATE VIII ''198 2o:o) 447] STUDIES ON GREGARINES— WATSON 237 PLATE IX 238 ILLINOIS BIOLOGICAL MONOGRAPHS [448 EXPLANATION OF PLATE Fig. 203. Pileocephalus blaberae (Frenzel) Labbe. After Frenzel, 1892, Plate VIII, Fig. 23. Fig. 204. Gregarina davini Leger and Duboscq. After Leger and Duboscq, iSgg, Fig. 3- Fig. 205. Gregarina galUveri Watson, X 100. Fig. 206. Gregarina stygia Watson, X 245. Fig. 207. Gregarina illinensis Watson, X 100. Fig. 208. Leidyana erratica (Crawley) Watson, X 245. Fig. 209. Leidyana gryllorum (Cuenot) Watson. After Cuenot, 1901, Plate XX, Fig. 27. Fig. 210. Gregarina nigra Watson, X 60. Fig. 211. Hirmocystis gryllotalpae (Leger) Labbe. After Leger, 1892, Plate VI, Fig. S- Figs. 212, 213. Actinocephalus acutispora Leger. After Leger, 1892, Plate XIV, Fig. 6; Fig. 7. Fig. 214. Beloides firmus (Leger) Labbe. After Leger, 1892, Plate XVII, Fig. 5. Fig. 215. Acanthospora pileata Leger. After Leger, 1892, Plate XV, Fig. 4. Fig. 216. Ancyrophora uncinata Leger. After Leger, 1892, Plate XIV, Fig. 8. Fig. 217. Gregarina acuta (Leger) Labbe. After Leger, 1892, Plate VI, Fig.- 10. m ::^m.'\- 203 ,1 ' *"■ 204 205 \Oj 206 •it %Sj 208 209 210 211 213 207 il Wi 2U6 1 1 " 217 ■• 212 PLATE IX 214 '''^^215 '•49] STUDIES ON GREGARINES -^WATSON 239 PLATE X 240 ILLINOIS BIOLOGICAL MONOGRAPHS [4S0 EXPLANATION OF PLATE Figures 218-239. Leidyana erratica (Crawley) Watson. Fig. 218. An adult sporont, X 245. Fig. 2ig. A younger slender sporont, nearly transparent, X 245. Fig. 220. Another adult sporont, X 245. Fig. 221. An old sporont, dense, compact and sluggish, just preparatory to cyst formation, X 245. Figs. 222, 223. Drawings to illustrate bending of the body, X 245. Fig. 224. The trophozoite attached to a host cell, X 245. Fig. 225. A larger trophozoite with an incipient protomerite, X 245. Fig. 226. Fully developed but still attached trophozoites, X 245. Fig. 227. An individual with epimerite, free in intestine and nearly as large as the adults, X 245. Fig. 228. A section of the caeca indicating that this organ is frequently the seat of infection. Fig. 229. The sluggish sporonts attached by the sticky secretion from their bodies. They are not attached anterio-posteriorly by means of a socket as in the genus Gregarina but haphazard and barely contiguous. Fig. 230. A cluster of sluggish fully matured sporonts, several of which formed cysts while on the slide under observation, X 60. Fig. 231. An adult sporont from the original of Crawley and called by him Stenophora erratica. After Crawley, 1903, Plate III, Fig. 34. Fig. 232. Longitudinal section of a portion of the deutomerite, indicating the deeply staining myonemes cut crosswise, just within the epicyte wall, X 500- Fig. 233. A sporont in the process of contortive and progressive movement. Fig. 234. Two sporonts in the process of rotation previous to cyst-formation. The soporonts are not attached. X 120. Fig. 235. A cyst still in rotation with a thin transparent wall, X 60. Fig. 236. A cluster of sporonts after half an hour on a slide, endeavoring to free themselves from threads at the posterior end which hold them to the debris. The sporonts are greatly stretched owing to their efforts to mctve forward. Fig. 237. A protomerite with an apical papilla. The animal is collapsing from evaporation of the medium. X 245. Fig. 238. A cyst still in rotation, the nuclei faintly visible, the protomerites still distinct and the transparent layer thick. X 60. Fig. 239. The nuclei have now disappeared and the protomerites are still visible as lighter areas. X 60. SijSiSfeft;- :'; \: ■^::v.:::;;: f: .V K^SSi5vS?& :j :: /^ :l0^&M&f-'- i': i: 1= '■i^ii''^W^^^^^^'^^'!'<': |:|i^;Slj^;^;s;JS;j l^sf^Jl 1 :i "j; II (i -i \S0ti/i-!!&iijM' 1; I; ;: . ;: Kt^^':-;^>^^';;V.■.■.■.- ;V; ; :i!&>^:ii-U:'yS-"' Hpi^^^ 1 1 /2 ^ii«ii "s i-219 ^iS 220 224 225 226 232 222 \ ' 223 221 /)M' :K --v iA f*?,-.'- :>;■ •■.'■.■'V'- ^ •1?;, •■;«;*,' .•■■v->;;-' m:.'y'-t ■■■•' ■■t.'-i'''-" ;?* ;v;:"w «■■>:-' .-;,-:.. ;*;.. ■■ ■:.- ;»'.•«:- ?^^ 'J:*Vi,-i =V ■•'i!\. '•.' vi-v.o; -■■ --■=- ' ■'"' ^■^i'''?%.-V*-' '■*S*: 22d m '227 ■SA^J^ 23r 234 -253 r ..,^ Vx 235 2cf6- 237 PLATE X 451] STUDIES ON GREG ARINES— WATSON 241 PLATE XI 242 ILLINOIS BIOLOGICAL MONOGRAPHS [452 EXPLANATION OF PLATE Figures 240-255. Leidyana erratica (Crawley) Watson. Fig. 240. The protomerites are visible as slightly dense areas; the transparent layer has become still wider. X 60. Fig. 241. The outside layer is much wider than before and the inner mass smaller because of the exudation of liquids. The line of separation be- tween the two sporonts is now obliterated and the cyst is a homo- geneous mass. X 60. Fig. 242. The protoplasm is collected in small spherical masses. X 60. Fig. 243. Section of a sporont stained on the slide, showing the longitudinal striations and the myonemes, which form a horizontal network of fibrillae. X 500. Fig. 244. A segment of the cyst in the stage shown in Fig. 242. The gametes are being formed from the outer parts of these protoplasmic masses. X 245. Fig. 245. Six spore dutcs are indicated by orange colored condensation discs on the surface of the cyst mass. X 60. Fig. 246. The spore ducts have grown from the periphery inward to the central part of the mass. X 245. Figs. 247, 248. The ducts extending outward from the periphery into the trans- parent cyst wall. X 245. Fig. 249. A mature cyst from which the spores are being extruded in chains, X 245. Fig. 250. Cross section of an intestine heavily infected with parasites; the gre- garines remain in the epithelial region of the intestine rather than among the food masses where they would easily be swept along by peristaltic movement. Fig. 251. A gamete taken from a cyst which was crushed at the end of about thirty hours. Diagramatic. Fig. 252. Two isogametes which have just fused, from a cyst of about thirty-five hours. Diagramatic. Fig. 253. A later stage in the fusion of the isogametes. Diagramatic. Fig. 254. A zygote formed by the fusion of the two gametes. X 810. Fig. 255. Ripe spores from a fully developed cyst of about forty-eight hours, X 810. :M'?vi'i"'**l''^'"'.'\ \ 2^0 241 ■■■■■ 24» 1^1^;;;; aJ43 ?:g^J;^44 -2^5 .,, 2i7 -■ 250 B46 '■■■■ 'f":?rm-:pW / / * 2S1 248 (•B:252 253 r'\ ■■..>■/:. ■■■it..... !!!.:;v ■.-.;' .; /■..■;'. \\ , ■•4. ■■.*■■--.'— ■■.-_/■; /< ■■-..'i.^ ^54 PLATE XI 453] STUDIES ON GREGARINES ^WATSON 243 PLATE XII 244 ILLINOIS BIOLOGICAL MONOGRAPHS [454 EXPLANATION OF PLATE Figs. 256, 257, 258, 259. Steinina harpali Watson. Sporont, X 245; early stage of epimerite development, X 245; middle stage of epimerite devel- opment, X 24s ; late stage in development, X 245. Figs. 260, 261. Gregarina udeopsyllae Watson. An association of sporonts, X 74; protomerite, X 245. Figs. 262, 263, 264. Gregarina platyni Watson. An association, X 24S; an asso- ciation, X 74; epimerite of a young individual, X 245. Figs. 265, 266, 267, 268. Hirmocystis harpcdi Watson. Association of four spo- ronts, X 74; association of three sporonts, X 74; association of two sporonts, X 74; young individual, with epimerite, X 245. Fig. 269. Steinina harpali Watson. A sporont, X 245. Figs. 270, 272. Echinomera hispida (Schneider) Labbe. A protomerite, X 245; sporont, X 245. Fig. 271. Gregarina rigida (Hall) Ellis. An association, X 60. Figs. 273, 274. Hirmocystis harpali Watson. Protomerite, X 245; linking device between primite and satellite, X 245. 260 ■257 /I f j 258 11 ^ 265 266 V'i ■•■'^:...„„rf^'''26» asfe /"'■" 259 2« . .263 264 PLATE XII [267 270 271 273, 272 274 4SS] STUDIES ON GREGARINES— WATSON 245 PLATE XIII / 246 ILLINOIS BIOLOGICAL MONOGRAPHS [456 EXPLANATION OF PLATE Figures 275-289. Gregarina galliveri Watson. Fig. 275. A large association, X 100. Fig. 276. A smaller association, X 100. Fig. 277. Association at beginning of cyst formation, sporonts beginning to ro- tate, X 100. Fig. 278. Association in process of rotation, X 100. Fig. 279. Complete cyst, still rotating, X 100. Fig. 280. Cyst after rotation has ended, X 100. Fig. 281. The sporont walls and nuclei have now disappeared and the contents have become homogenous and shrunken, X 100. Fig. 282. The protoplasm has begun to collect in masses. X loo- Fig. 283. Cross section of cyst in stage shown in Fig. 282, showing incipient gametes on surface of endocyte. X 245. Fig. 284. Three orange colored discs have appeared on the surface of the cyst. X 100. Fig. 285. Nine discs are now present. X 100. Fig. 286. Exudation of spores from the ripe cyst through the long spore ducts. The exuded spores remain attached in short chains, X 60. Fig. 287. A ripe spore with sporozoites. X 810. Fig. 288. An association from a starved host, showing the concavity in the end of the primite. X 100. Fig. 289. A trophozoite attached to the epithelial wall of the host. X loo- ''"■■-■'■■■"'. 27 :> 276 • 280 277 Z82 9 279 278 \^.i^,nMi;i% i §} ] i \. ...'289 ■M\\ '^^28;i 281 '284 2So * 287 288 286 PLATE XIII 457] STUDIES ON GREGARINES — WATSON 247 PLATE XIV 248 ILLINOIS BIOLOGICAL MONOGRAPHS [458 EXPLANATION OF PLATE Figures 290-311. Gregarina rigida (Hall) Ellis. Figs. 290, 291. Mature associations, X 195. Fig. 292. Trophozoite with epimerite, free in liimen of intestine. X 195. Figs. 293, 294, 29s, 296. Free trophozoite, with epimerite in process of constriction and destruction. X 195. Fig. 297. Longitudinal section of protomerite of satellite, showing indentation for interlocking with primite. X 195. Fig. 298. Longitudinal section of protomerite of primite, showing slight indenta- tion in apex and slightly papillate condition sometimes seen. X I9S- Figs. 299-304. Various appearances of chromatin in the nucleus in sporonts of dif- ferent ages. X 195. Fig. 305. View of protomerite of primite showing thickness of sarcocyte and in- dentation at apex. X I9S- Fig. 306. Myonemes in deutomerite df a nearly transparent individual from a starved host. X 510. Fig. 307. Longitudinal striations of deutomerite. X Sio. Fig. 308. Cross section of deutomerite through nucleus of a mature sporont show- ing longitudinal striations which appear as cilia, the transparent sar- cocyte, endocyte somewhat mottled in appearance, nucleus slightly shrunken from endocyte in the fixing process, and irregular masses of chromatin, forming the karyosomes. X 195. Fig. 309. A young trophozoite attached to an epithelial cell of the host intestine. X I9S. Fig. 310. An association held to a large mass of debris by threads from the poste- rior end of the satellite. Debris has become attached to the threads also. X 30. Fig. 311. Enlarged view showing small particles of carmine attached to threads. X I9S. 29:^ 293 ?«■-.. 294 291 mid ^^^ 290 297 296 459] STUDIES ON GREGARINES— WATSON 249 PLATE XV 250 ILLINOIS BIOLOGICAL MONOGRAPHS [460 EXPLANATION OF PLATE Figures 312-332; 336-338. Gregarina rigida (Hall) Ellis. Figs. 312-316. An association of sporonts in the process of rotation preparatory to cyst formation. X 60. Fig. 317. The completed cyst. One nucleus is still visible. X 60. Fig. 318. The protomerite has become homogeneous and the walls of the sporonts have disappeared. X 60. Fig. 3ig. A cyst with the protoplasm collected into papillae. X 60. Fig. 320. Two gametes from opposite sides of a cyst, which have just united. X 740. Fig. 321. The union of gametes is becoming firmer and their chromatin is split- ting. X 740. Fig. 322. Further breaking up of the chromatin and liberation of a polar body (?). X 740. Fig. 323. Eight karyosomes have been formed and the wall of separation between the gametes has disappeared. X 740. Fig. 324. The zygote has become ellipsoidal and its wall has developed. X 740. Fig. 325. A cyst with twelve orange discs on its surface. The spores have col- lected in the center. X 60. Fig. 326. Short spore ducts have developed radiating from the center of the cyst like spokes of a wheel. X 60. Fig. 327. Enlarged view of a spore duct. X 195. Fig. 328. The spore duct has become inverted and the spores are being extruded. The cyst has shrunken greatly. X 195. Fig. 329. A cyst with four spore ducts in the process of extruding spores. X 60. Fig. 330. A spore, showing the cilia or spines at the ends by which the spores are held together in chains. The cross-markings indicate faint lines of separation between developing sporozoites. Enlarged free-hand from highest power (X 1760). Fig. 331. Spore, showing chromatin collected in five masses. Fig. 332. A well developed spore in the process of exuding falciform sporozoites through an apparent pore at one end. Taken from the intestine of a grasshopper. Fig. 333' An association of Gregarina nigra Watson, X 60. This figure, at the left of the plate, is labelled 336. Fig. 334. Another association of G. nigra. X 60. Fig- 335- Protomerite of G. nigra, showing indentation at apex. X 195. Sporadic sporonts. Fig. 336. Unique association of three sporonts of G. rigida, X 60. Fig. 337. Unique association of G. rigida, the primite with an epimerite. X 60. Fig. 338. Unique association of G. rigida, two satellites forming an association. X 60. f \ cy y„ ... J '^ (... ■■■■ Sl£ Mil 3X3 ,'-< r--.."\ i{-s> 'V ■}■ ,, '■>-^.---' 1 J / j /^i/'"i J / N •?..' /■ ' ' \. \.3 ■■ ■•'313 r.-.l«»3r-^l,., "v. ■••„. ''--X/W^l *J/^>' ''3^5 •■ ■■<■ ■•■,/''5?K'ES. , -■■ - \ .-■•• ^dl7$ \\J I) ■•'■'•' 'if ill -•iy^,^;;;^., 355 K::,/336- 334 330 33i 326. J ^:- f'-i^-^^g Tip) 320 323 336 • .■■>*s?>. 338 PLATE XV INDEX Acanthospora pileata, 162 polymorpha, 163 Acheta abbreviata, 102 Acilius sulcatus, 146 Acis sp., 162 Actinocephalus acus, 163 acutispora, 138 americanus, 139 brachydactylus, 203, 207 caudatus, 203, 212 conicus, 41, I2S, 134, 13s, 136, 143, 176 crassus, 141 digitatus, 138 dicaeli, 140 discaeli, 140 dujardini, 90 dytiscorum, 137 fimbriatus, loi, 124 gimbeli, 79, 142, 156, 169 harpali, 139, 156, 169, 204 lucani (us), 125, 134, 135, 138 octacanthus, 204, 212 pachydermus, loi, 124 repelini, 204, 212 rubecula, 150 sieboldi, 204, 207 stelliformis, 137 sp., 204, 208 striatus, 90 tipulae, 204, 213 zophus, 141, 142, 197 Acutispora macrocephala, 86 Aeschna constricta, 204, 207 Aeschna sp., 203, 207 Agrion sp., 204, 205, 207 Agrippina bona, 206, 208 AUecula sp., 174 AUobophora foetida, 13 Alobates pennsylvanica, 207 Amara angustata, 14, 154 cuprea, 173 Amphitrite sp., 13 Amphorella polydesmi, 52, Tj Amphorocephalus actinotus, 91, 92, 93 amphorellus, 91 Amphoroides calverti, 66, 78 fontariae, 60, 61 polydesmi, 51, 61, 77 polydesmivirginiensis, 51, 52 Anaspides sp., 206, 207 Ancyrophora gracilis, 163, 164 uncinata, 137, 164 Anthorhynchus cratoparis, 144 fissidens, 205, 212 goronowitschi, 205 philicus, 143 sophiae, 205, 212 Anthrenus verbasci, 151 Aphodius nitidulus, 133 prodromus, 133 Arphia sulphuria, 14 Arrhenoplita bicornis, 195 Asida grisea, 159 opaca, 162 servillei, 167 Astacus sp., 201, 207 Asterophora cratoparis, 144 elegans, 204, 212 mucronata, 212 philica, 143, 198 Attagenus pellio, 151 Atyaephyra desmaresti, 203, 207 Audouinia sp., 206, 207 B Balanus improvisus, 202, 207 sp., 202, 203, 205, 206, 207 Beloides firmus, 14S tenuis, 145 Bibio sp., 204, 207 Note. The extended description of a species is indicated under its correct name by printing the page number in heavy type. 2S1 252 STUDIES ON GREGARINES —WATSON [462 Blabera claraziana, 123 Blaniulus hirsutus, 62 Blaps mortisaga, 160 Blatta orientalis, 99, no, in Blattella germanica, 99 lapponica, 122 Boletophagus cornutus, 195 Bothriopsis histrio, 146 terpsichorella, 146, 148 Brachyiulus pusillus lusitanus, 62 superus, 62 Brachystola magna, 106 C Callipus lactarius, 12, 72, 78 Cancer pagurus, 203, 207 Carabus auratus, 138, 163 sp., 163 violaceus, 138, 163 Ceratophyllus fasciatus, 206, 208 Cermatia forceps, 87, 88 Cetonia aurata, 194 Ceuthophilus latens, 107, 115 maculatus, 167, 115 stygius, 14, 114 valgus, 108 Chaetechelyne vesuviana, 94 Chilopod Gregarine Parasites, list of, 80 Chlaenius vestitus, 138 Chordeuma silvestre, 68 Chrysomela haemoptera, 176 violacea, 176 Chtamalus stellatus, 203, 208 Cistelides sp., 163 Clepsidrina acridiorum, 104 acuta, 178 blattarum, 99 conoidea, 97 cuneata, 153, 170 gryllorum, 102, 103, 120 Laucournetensis, 177 longirostris, 177 tnacropephala, 102 mimosa, 173 Munieri, 176 ovata, gy, 173 paranensis, 104 polymorpha, 152, 153, 170,. 172, 173 polymorpha var. cuneata, 170, 171, 173 polymorpha typica, 173 sp., 102 Cnemidospora lutea, 76 Spiroboli, 59, 77 Coccinella novemnotata, 14, 182 sp., 14, 184, l8s Coleorhynchus heros, 204, 211 Colymbetes fuscus, 146 . sp., 148, 164 Cometoides capitatus, 164, 165 crinitus, 165 Conica, 134 Coptotomus interrogatus, 14, 191, 196 Corycella armata, 165 Corymetes ruf., 149 Craspedosoma legeri, 68 rawlinsii simile, 65 Cratoparis lunatus, 144 Crypticus sp., 174 Cryptops anomalous lusitanus, 81 hortensis, 81 Ctenophora sp., 204, 208 Cyphon pallidulus, 167 Cyst Development and Dehiscence, 36 Cystocephalus algerianus, 157 Cysts and Cyst Formation, 34 D Dactylophorus robusta, 81 robustus, 81, 94 sp., 81, 94 Dendarus tristis Rossi-coarcticoUis, 180 Dendrocoelum lacteum, 202, 208 Dermestes lardarius, 14S, 15° peruvianus, 150 sp., 151 undulatus, 145 vulpinus, 150 Didymophyes gigantea, 132 leuckarti, 133 longissima, 200, 209, 211 minuta, 133, 182, 199 paradoxa, 132 rara, 132 Diplopod Gregarine Parasites, list of, 48 Dicaelus ovalis, 140 Dissosteira Carolina, 14, 100, 124 463] INDEX 253 Dorcus parallelopipedus, 135 Dromia dromia, 203, 209 Dufouria agilis, 88, 148 Dytiscus marginalis, 137 sp., 137, 146, 164 E Echinocephalus hispidus, 84, 195 horridus, 86 Echinomera hispida, 82, 84, 85 horrida, 85, 86 Ectobia germanica, 99 lapponica, 122 Eirmocystis gryllotalpae, 123 asidae, 167 Elater sp., 194 Eleodes sp., 162 Embia sp., 201, 209 Enchytraeus abbidis, 13 Encoptolophus sordidis, 14, 106, 116 Ephemera sp., 201, 202, 209 Eryx ater, 181 Eupagurus prideauxi, 203, 209 Euryurus erythropygus, 12, 74 Eusattus sp., 162 Euspora fallax, 167, 202 lucani, 179 F Fontaria sp., 60 virginiensis, 52 Forficula auricularia, 98 Frenzelina chtamali, 203, 208 conformis, 203, 211 delphinia, 38, 203, 213 dromiae, 203, 209 fossor, 203, 212 nigrofusca, 203, 213 ocellata, 203, 209 Olivia, 203, 210 portunidarum, 203, 212 praemorsa, 203, 207, G Galerita bicolor, 139 Gammarus pulex, 200, 202, 209 sp., 201, 210 Gamocystis ephemerae, 202, 209 tenax, 122, 202 Ganymedes anaspidis, 206, 207 Gelasimus pugilator, 13 pugnax, 13 Geniorhynchus aeschna, 204, 207 monnieri, 204, 210 Geotrupes sp., 133 stercorarius, 133 Gigaductus kingi, 106 parvus, 107, 178 Glomeris sp., y7 Glossiphonia sp., 202, 209 Gregarina Achetae, loi Achetae abbreviatae, loi, 119 acridiorum, 104 actinotus, 91 acus, 163, 164 acuta, 178 amarae, 173 barbarara, 182, 184 bergi, 149 blaberae, 123 Blattae Orientalis, 99, 100 blattarum, 99, 105, no, in boletophagi, 195 brevirostra, 149, 160 Brevirostrata, 160 brevirostris, 160 calverti, 66, 78 cavalierina, 180 clausi, 200, 212 conica, 96, 125, 134 consobrina, 108, 115, 118 coptotomi, 196 crassa, 199 cuneata, 170, 171, 172, 173, 178, 197 curvata, 194 Davini, 126, 209 dicaeli, 140 discaeli,' 140 Dytiscorum, 137, 164 elaterae, 194, 196 elongata, 174 ensiformis, 200, 212 fimbriata, 100, 124 flava, 200, 212 fragilis, 185, 190 galliveri, iii gammari, 200, 209 gigantea, 132 254 STUDIES ON GREGARINES —WATSON [464 Gregarina globosa, 191 gracilis, 188 granulosa, 201, 209 grisea, 142, 181 gryllorum, 120 guatemalensis, 181 harpali, 139 hyalocephala, 97 illinensis, 108 intestinalis 189 juli, 49, 50, 53, 55, 56, 57, 58 juli marginati, 49, 50, 55, S6, 57 julipusilli, SO, 53, 54, 55 katherina, 182, 184, 185 kingi, 106, 112, 113 lagenoides, 201, 210 larvata, 49, 50, 55, 57 laucournetensis, 177, 179 Locustae Carolinae, 100, 124 locustae, 97, 100 longa, 201, 213 longicoUis, 159 longiducta, 107, 115, 118 longirostris, 177, 179 lucani, 134, 179 macrocephala, 96, 102, 120 marteli, 209 megacephala, 87, 88 melolonthae, 175 Melolonthae brunneae, 175 melanopli, 105 microcephala, 195 miliaria, 201, 207, 209 minuta, 133, 134, 182, 198, 199 monarchia, 189, 190 Mortisagae, 159 munieri, 176 mystacidorum, 201, 211 nereidis denticulata, 201 nigra, 116 oblonga, 96, 103 oblongata, 159 ovalis, 152, 196 ovata, 97 oviceps, 101 panchlorae, 103 paradoxa, 55, 56, 57, 132 paranensis, 104 parva, 156, 169, 178 passali, 175 passali cornuti, 175 philica, 143, 198 platyni, 192 podurae, 201, 211 polydesmi, 51 polydesmivirginiensis, 51, 52, 77 polymorpha, 152, 170, 171, 172., 173 polymorpha var. cuneata, 170 praemorsa, 202, 212 psocorum, 98, 202, 212 pterotracheae, 202, 212 rigida, 37, 105, 116 rubecula, 150 salpae, 202, 212 scarabaei, 174 scolopendra, 83, 94 serpentula, 104, 169 scarabaei relicti, 174 socialis, 180 soror, 127 sp. (Bolsius), 202, 209 sp. (Crawley), 198 sp. (Gaede), 159 sp. (Hallez), 202, 208 sp. (Kolliker), 202, 207 sp. (Mawrodiadi), 202, 207 sp. (Moseley), 202, 211 sp. (Pfeiffer), 202, 209 sp. (Porter), 202, 212 sp. (Ritter), 202, 211 sp. (Solger), 202, 207 sphaerulosa, 123, 126 statirae, 177 steini, 178 stygia, 114, 115, 118 tenebrionella, 187 tenuis, 174 termitis, 202, 213 udeopsyllae, 117 valettei, 202, 212 xylopini, 170, 197 Gryllomorpha dalmatina, 126 Gryllotalpa gryllotalpa, 123 Gryllus abbreviatus, 14, 102, 107, ill, 118, 121 46S] INDEX 255 Gryllus americanus, 102 campestris, 96, 98 domesticus, 103, 120, 121, 169 pennsylvanica, 118 sylvestris, 103 Gyrinus natator, 166 H Harpalus caliginosus, 140, 179 pennsylvanicus, 142, 155, 168, 179 Helenophorus coUaris, 161 Heliodrilus caliginosus, 13 Helops striatus, 158 Herpebdella sp., 202, 210 Hesperotettix pratensis, 14, 106 Himantarium gabrielis, 89 Hirmocystis asidae, 167 gryllotalpae, 123, 126, 127 harpali, 156, 168 ovalis, 196 polymorpha, 202, 210 rigida, 105 ventricosa, 202, 211, 213 Hirudinea sp., 203, 210 Hoplocephalus bicornis, 19S Hqplorhynchus actinotus, 91 scolopendras, 92 Hosts Infected with Gregarines, 12 Hyalospora affinis, 122 reduvii, 202, 212 roscoviana, 121, 166 Hydaticus cinereus, 146 Hydrobius sp., 165 Hydrophilus piceus, 149 sp., 147, 160 Hydrous caraboides, 163 sp., i6s Ischnoptera pennsylvanica, 14, 108, no, III lulus londinensis, 58 albipes, 58 J Julus albipes, s6, s8 boleti, 58 fallax, 55, 56, 58 londinensis, 58 marginatus, 49 mediterraneus, 58 minitus, 54 pusillus, 54 sabulosus, 55, 56, 58 sp., 53 terrestris, 55, 56, 58 varius, 64 L Legeria agilis, 88, 147, 148 terpischorella, 146 Leidyana erratica, 21, 22, 25, 29, 34, 79 118, 121 gryllorum, 103, 120 Lepisma saccharina, 201, 210 Leptochirus edax, 141, 157 Libellules sp., 204, 210 Libinia dubia, 13, 203, 210 emarginata, 13 Life History of a Typical Cephaline Gregarine, 32 Limnobia sp., 202, 210 Limnophilus rhombicus, 164 Lithobius calcaratus, 86 coloradensis, 85 forcipatus, 85 forficatus, 85, 87, 90 Localities Represented by New Species, 14 Lophocephalus insignis, 87, 158 Lophorhynchus insignis, 158 Lucanus dama, 180 parallelopipedus, 125, 135, 176 Lumbricus terrestris, 13 Lysiopetalum foetidissimum, 66 lactarium, 66, 78 M Machilus cylindrica, 122 Melolontha sp., 152 Melolonthae, 175 Melolonthae brunneae, 175 Melanoplus acridiorum, 14 angustipennes, 106 atlanis, 106 bivitattus, 14, 106 coloradensis, 106 differentialis, 14, 106 femoratus, 106 femur-rubrum, 14, 106, 116 luridus, 106 Menospora polyacantha, 205, 207 Metamera schubergi, 203, 210 256 STUDIES ON GREGARINES —WATSON [466 Monocystis acidiae, l6, 19 Morica sp., 158 Morphology of Gregarines, 27 Morphology of the sporonts, 27 Movement in Gregarines, 20 Mystacida, sp., 201, 211 Mystacides sp., 205, 211 N Necrobia ruficoUis, 149 Nematoides fusiformis, 206 Nemobius sylvestris, 97, 103 Nepa sp., 204, 211 Nereis sp., 13 Nina giardi, 83 Nina giardi corsicum, 83 gracilis, 18, 19 82, 94 indicia, 84 Ninus interstitialis, 181 Nyctobates barbata, 141 pennsylvanica, 143 O Ocypus olens, 138 Oedipoda coerulescens, 127 migratoriae, 96 stridula, 96 Omoplus sp., 163 Oocephalus hispanus, 158 Opatrum sabulosum, 159 Orchesella villosa, 201, 211 Orchestia agilis, 13 littorea, 200, 211 Orthomorpha coarctata, 70 gracilis, 69 sp., 69 Orthopteran Gregarine Parasites, list of, 94 Oryctes nasicornis, 132 sp., f32 P Pachygraspus marmoratus, 203, 211 Pachyrhina sp., 202 Pamphagus sp., 211 Panchlora exoleta, 103 Parajulus impressus, 12, 70 sp., S3, 69 varius, 64 venustus, 69 Parnus sp., 177 Passalus cornutus, 175 Peripatus sp., 202, 211 Periplaneta americana, 99, iii orientalis, 99, 105, iii Perophora annectens, 202, 211 Petrobius maritimus, 121, 166 Phalangida sp., 205, 212 Phalangides sp., 205, 212 Phalangium sp., 205, 212 Phallusia sp., 206, 212 Phialis ornata, 148 Phialoides ornata, 41, 148, 160 Phronima sp., 200, 212 Phryganea rhomb., 164 sp., 204, 206, 212 Phyllognathus sp., 132 Pileocephalus bergi, 149 blaberate, 123 chinensis, 205, 211 Pimelia sp., 157 Pinnotheres pisum, 203, 212 Platycarcinus sp., 202, 212 Platynus ruficollis, 192 Poecilus cupreus, 173 Pogonites capitatus, 164 crinitus, 165 Pollicipes sp., 202, 212 Polydesmus complanatus, 52, yj dispar, yj sp., 60 virginiensis, 52 Polyxenus lagurus, 65 Portunus arcuatus, 203, 212 Previous Work on Gregarines, 9 Psocus sp., 202, 212 Pterocephalus Giardi, 83 Giardi corsicum, 83 nobilis, 82 Pterostichus stygicus, 13, 189, 190 Pteotrachea sp., 202, 212 Pyxinia crystalligera, 150, 204 frenzeli, 17, 151 mobuszi, 18, 151 rubecula, 150 R Reduvius personatus, 202, 212 Relation of Parasite to Host Tissue, 16 Rhizinia oblongata, 159 sp., 194 467] INDEX 2S7 Rhizotrogus aestivus, 167 sp., 138, 152 Stella, 8g Rhopalonia geophili, 88 Rhyacophila sp., 204, 212 Rhynchobolus americanus, 202, 212 S Salpa confoederata, 200, 212 aeruginosa, 200, 212 maxima, 202, 212 vagina, 200, 212 Scarabaeus relictus, 174 Schistocerca americana, 14, 106 paranensis, 104 Schizophyllum corsicum, 63 mediterraneum, 58 sabulosum, 58 Schneideria mucronata, 204, 207 Sciadophora phalangii, 205, 212 Sciara sp., 212 Scolopendra cingulata, 82, 90 heros, 91 hispanica, 82 morsitans, 83 oraniensis, 83 oraniensis lusitanica, 84 subspinipes, 84 woodi, 92 ' Scolopocryptops sexspinosus, 12, 92 sp., 92 Scutigera forceps, 87 sp., 87 Seasonal Variation Within the Host, IS Seat of Infection, 14 Sericostoma sp., 164, 205, 213 Silpha laevigata, 139 thoracica, 163 Spaerocephalus ophioides, 162 Sphaerocystis simplex, 166 Sphaerorhynchus ophioides, 162 Sphingonotus sp., 104 Spirobolus sp., 60 spinigerus, 49 Sporadina curvata, 194 Dytiscorum, 137 JuH, 55 oblongata, 159 Sporont Maturity, 33 Stapytinus olens, 138 Statira unicolor, 177 Steinina harpali, 155 obconica, 153 ovalis, 152 rotunda, 154 Stenocephalus juli, 49, 50, 55, 56, 57 Stenophora aculeata, 65 brolemanni, 28, 61 chordeume, 28, 61, 67 cockerellae, 69, 74, 143 Corsica, 68 dauphinia, 57, 59 diplocorpa, 28, 74, 76 elongata, 70, 74 erratica, 79, 119 fontariae, 60, 61, 68 gimbeli, 79, 142 .. impressa, 70 iuli, SS, s8, 62, 64, 66 iuli marginati, 49, S3 iulipusilli, S3, 120 juli, 49, so, S3, S4, 55. S6, 57, 62, 64, 66 julipusilli, 53, S4, 79 lactaria, 29, 30, 71, 72, 74 larvata, 49, Si, S6, 57, 74 nematoides, 29, 62, ^6 polydesmi, 28, 51, 52, 78 polyxeni, 65 producta, 64 robusta, 28, 69 silene, 28, 66 spiroboli, 28, 59, 60 varians, 28, 63 Stephanaphora crassa, 141 locutaecarolinae, 100, 124 lucani, 134, 136 pachyderma, 124 radiosa, 41, 134, 135 zopha, 141, 142 Stictospora provincialis, 152 Stigmatogaster gracilis, 89 Strongylosomum italicum, 62 Stylocephalus balani, 205, 207 brevirostris, 149, 160 caudatus, 205, 212 ensiferus, 157 gigatiteus, 162 gladiator, 161 heeri, 205, 212 ^' SS^i' 'i STUDIES ON GREGARINES -WATSON [46§ longicoUis, 159 oblongatus, 159, 160, 211 oligacanthus, 206, 207 phallusiae, 206, 212 sp., 197 Stylocystis ensifera, 157 praecox, 213 Stylorhynchus brevirostris, 160 gladiator, 161 longicoIHs, 159 oblongatus, 159 ovalis, 152, IS3, 171, 172, 173 Synopsis of Suborder Eugregarinae, 43 Summary, 25 T Taeniocystis truncata, 205, 213 Talorchestia longicornis, 13, 203 Tanypus sp., 204, 213 Technic, 7 Tenebrio castaneus, 181 molitor, 153, 170, 171, 172, 178 Termes sp., 202, 213 Terms Used in Describing Gregarines, 10 Thanasimus formicarius, 177 Timarcha tenebricosa, 135, 176 Tipula sp., 201, 202, 204, 213 Tribolium ferrugineum, 134, 154, 171, 182, 198 Trichorhynchus insignis, 87 lithobii, 93 pulcher, 87 Tridactylus sp., 97 Trox perlatus, 178 Tryxalis sp., 104 U Uca pugilator, 203, 213 Uca pugnax, 203, 213 Udeopsylla nigra, 117 Ulivina elliptica, 206, 207 Uradiophora communis, 203, 207 cuenoti, 203, 207 X Xiphorhynchus firmus, 145 tenuis, 145 Xylopinus saperdioides, 171, 197 TABLE OF ERRATA Page 18 line 3 for mobussi, read mbbussi 25 25 0.8, read 0.8 micron 28 30 (Fig. 70), read (Fig. 10) 29 24 Stenaphora, read Stenophora 47 transfer Genus 49 above Family 8 into Family,? 48 line 4 for Ulvina, read Ulivina 48 21 virginensiSj read vWginiensis 48 24 Julus boleti C. Koch, read lulus fallax Meinert 48 32 -Brachydesmus, read Brach- yiulus \ 49 20 1913a:286, read 1913b:286 53 2 [Figure 6], read [Figures 5 and 6] 56 34 iulu, read Jtlli 60 22 FONTARIA, read FON- TARIAE 60 24 1913:53, read 1903:53 60 26 fontaria, read fontariae 61 22 fontaria, read fontariae 64 31 Fabricus, read Fabricius 69 3 1912a:8.10, read 1912b:8-lD 69 18 1912:681-5, read 1912a:681-5 69 30 Orthomorpha coarctata, read Parajulus sp. 70 3 1912:685-6, read 1912a:68S-6 70 5 minimum 390 micra, read maximum 390 micra 80 35 after Scolopocryptops sexspino- sus insert Scolopocryptops sp. 81 7 for 1903:310-1, read 1903a:311 84 28 [Figure 32]^ read [Figufes 32, 270, 272] Page 90 line 1 94 19 94 20 94 36 95 3 95 10 95 30 96 23 97 27 97 34 98 1 99 35 100 34 101 5 102 25 102 26 103 16 104 2 104 33 108 14 41 8 68 28 68 33 106 8 125 25 143 11 for STJIIATIUS, read STRI- ATUS Oeipoda, read Oedipoda rmgratoriae, read imgratoria Schistocera, read Schisto- cerca atlanis, read otlantis 'Sehistocet'a, read Schisto- cerca (Diesing) Ellis, read . (Diesing) Watson ' Oedipda, read Oedipoda 1845:95, read 1848:194 1904:14-18, read 1904:64-87 :: 12, read :: 1 : 2 Blattae, read Blatta Dissosteria, read Dissosteira Stephanfihora, read Stepha- nqphora insert [Figure 199] for 1875:674, read 1875:574 1892:290-300, read 1892: 299-300 1893:811-13, read 1893a: 811-13 1900:140-44, read 1900:40-44 valgas, read valgus^ Stein, read Frantzius fontaria, read fontariae fontaria, read fontHriae luridis, read luridus Stein, read Frantzius Stein, read Frantzius