290 Sporozoa 



Monocystis Stein (7, 41; Fig. 6. 11, I), Nematocystis Hesse (7; Fig. 6. 1, B), Rhabdocystis 

 Coldt. 



Family 6. RJiynchocystidae. The family contains only the genus Rhyn- 

 chocystis Hesse (7, 133; Figs. 6. 2, C; 11, G). A mucron is more or less 

 evident. The body is usually elongated, sometimes with an anterior con- 

 ical or cylindrical "neck," and may be covered with cuticular "hairs." 

 Early syzygy does not occur and autotomy may precede the association. 

 Spores are typically spindle-shaped. 



Family 7. Schaudinnelidae. The only genus is Schaudinnella Nusbaum 

 (101; Fig. 6. 1, D), showing two types of gametocytes and well-marked 

 anisogamy. Trophozoites may be free or attached, the latter stage with a 

 primitive epimerite. 



Family 8. Stomatophoridae. A discoid sucker-like epimerite is charac- 

 teristic of the elongated to spheroid trophozoites. Early syzygy is unknown. 

 Spores are usually truncate spindles. 



The following genera are included: Albertisella Cognetti, Astrocystella Cognetti, 

 Beccaricystis Cognetti (Fig. 6. 11, L), Choanocystella Cognetti, Choanocystoides Cog- 

 netti (Fig. 6. 12, F), Craterocystis Cognetti (Fig. 6. 11, E), Stomatophora Drzewecki (8; 

 Fig. 6. 12, A, B). 



Family 9. Urosporidae. Form of the trophozoite varies in different 

 genera. Early syzygy is characteristic. The spore luembrane may be drawn 

 out into horns or flanges, and there is often a funnel-like depression at 

 one end. 



The family contains the following genera: Ceratospora Leger, Cystohia Mingazzini, 

 Gonospora Schneider (46; Fig. 6. 12, G, H), Lithocystis Giard (36; Fig. 6. 12, I), Ptero- 

 spora Racovitza and Labbe, Urospora Schneider (31, 92; Fig. 6. 12, C-E). 



Family 10. Zygocystidae. The trophozoites are commonly pyriform. 

 Early syzygy, sometimes with longitudinal pairing, is the rule. The spores 

 are spindle-shaped, with thickened poles. Species are known from the 

 seminal vesicles and coelom of oligochaetes. 



The family contains the genera Pleurocystis Hesse and Zvgocystis Stein (7, 133; Figs. 6. 

 2, E; 12, J). 



Subclass 2. Coccidia 



The Coccidia are predominantly parasites of epithelial tissues in 

 invertebrates (Annelida, Arthropoda, Mollusca) and vertebrates, and are 

 typically intracellular throughout most of their life-cycles. Reproduction 

 occurs in both asexual and sexual phases of the cycle, as in Schizogreg- 

 arinida. 



