GREGARINIDA 295 



lope is drawn out at one end in a bottle-neck fashion. Parasites 

 of the blood vessel and coelom of Holothuria, 



Cystohia irregularis (Minchin). In the blood vessel of Holo- 

 thuria nigra. 



Genus Lithocystis Giard. Body large; form ovoid or cylindri- 

 cal. Body-surface with hair-like processes; endoplasm with 

 crystals of calcium oxalate. The spore is ovoid, but its envelope 

 with a long process; arranged radially. Number of sporozoites 

 eight (?). 



Lithocystis scJineideri Giard. In the coelom of echinoderms. 



Lithocystis brachycercus Pixell-Goodrich (Fig. 124, g, h). In 

 the coelom of Chiridota laevis. 



Genus Urospora Schneider. Body large; frequently in 

 association. Cyst spherical. Each individual undergoes sporu- 

 lation independently. The spore is oval and possesses a long 

 filamentous process at one end. In the body cavity of Tubifex, 

 Nemertinea, Sipunculus, Synapta, and Chiridota. Several 

 species 



Urospora saeniiridis (Kolliker). In the seminal vesicle and 

 general body cavity of Tiibifex tubifex 



Urospora chiridotae (Dogiel) (Fig. 124, i). In the blood 

 vessel of Chiridota laevis. 



Genus Gonospora Schneider. Trophozoite large and poly- 

 morphic, oval, pyriform or vermiform. Cysts spherical. The 

 ends of the spore are dissimilar. In the coelom of polychaetes. 

 Several species. 



Gonospora minchini Goodrich and Pixell-Goodrich (Fig. 

 124, J-/). In the coelom of Arenicola ecaudata. Young tropho- 

 zoites invade and grow within the egg. 



Genus Lankesteria Mingazzini. Body more or less spatulate 

 and small. Cysts spherical. The spore is oval and flattened and 

 contains eight sporozoites. 



Lankesteria planariae (Mingazzini). In the gastro-vascular 

 cavity of Planaria. 



Lankesteria culicis (Ross) (Fig. 123). In the gut of Aedes 

 aegypti. 



Genus Nematocystis Hesse. Trophozoites are nematode- 

 like. 



Nematocystis magna (Schmidt). In Lumbricus terrestris. 



