SPOROZOA, GREGARINIDA 431 



become set free in the lumen of the tubules pass into the intestine, 

 from which they are discharged into water. Larvae swallow the 

 spores and acquire infection. 



Eugregarinina are divided into 2 tribes : 



Trophozoite not septate Tribe 1 Acephalina 



Trophozoite septate Tribe 2 Cephalina (p. 440) 



Tribe 1 Acephalina Kolliker 



The acephalines are mainly found in the body cavity and organs 

 associated with it. The infection begins by the ingestion of mature 

 spores by a host, in the digestive tract of which the sporozoites are 

 set free and undergo development or make their way through the 

 gut wall and reach the coelom or various organs such as seminal 

 vesicles. Young trophozoites are intracellular, while more mature 

 forms are either intracellular or extracellular. 



Spores with similar extremities 

 Spores biconical 

 Sporadins solitary 



Anterior end not differentiated Family 1 Monocystidae 



Anterior end conical or cylindro-conical 



Family 2 Rhynchocystidae (p. 433) 



Sporadins in syzygy 



Spores with thickenings at ends. .Family 3 Zygocystidae (p. 434) 

 Spores without thickenings. .Family 4 Aikinetocystidae (p. 434) 

 Spores not biconical 



Spores navicular Family 5 Stomatophoridae (p. 434) 



Spores round or oval 



No encystment Family 6 Schaudinnellidae (p. 436) 



2 sporadins encyst together Family 7 Diplocystidae (p. 437) 



Spores with dissimilar ends 



Spores with epispore Family 8 Urosporidae (p. 438) 



Spores without epispore Family 9 Allantocystidae (p. 440) 



Spores unobserved; grown trophozoites with cup-like depression at 

 posterior end for syzygy Family 10 Ganymedidae (p. 440) 



Family 1 Monocystidae Blitschli 



Trophozoites spheroidal to cylindrical; anterior end not differ- 

 entiated; solitary; spores biconical, without any spines, with 8 spo- 

 rozoites. 



Genus Monocystis Stein. Trophozoites variable in form; motile; 

 incomplete sporulation in cyst; spore biconical, symmetrical; in 

 coelom or seminal vesicles of oligochaetes. Numerous species. 



M. ventrosa Berlin (Fig. 202, a-c). Sporadins 109-183^ by 72- 

 135m; nucleus up to 43m by 20/x; cysts 185-223^ by 154-182/x; 



