300 Sporozoa 



Family 2. Caryotrophidoe. The oocyst contains many sporocysts, each 

 with many sporozoites. The merogonic cycle involves division of the 

 schizont into a number of meroblasts, each of which produces merozoites. 

 Microgametogenesis involves a similar process. The only genus is Caryo- 

 tropha Siedlecki (Figs. 6. 13, B-D; 17, J). 



Family 3. Crypiosporidiidae. Development is extracellular, the parasites 

 apparently being embedded in the mucus covering the epithelium of the 

 gut. The small oocyst contains four sporozoites but no sporocysts. Certain 

 parasites of mice have been assigned to the only genus, Cryptosporidium, 

 Tyzzer (134; Fig. 6. 17, A-E). 



Family 4. Eimeriidae. The characteristics of the family are somewhat 



Fig. 6. 19. A-F. Shellackia bolivari, x900 (after Reichenow): zygote in 

 subepithelial tissue, intestine of li/ard (A); development of sporozoites from 

 zygote (B, C); a sporozoite in an erythrocyte (D); sporozoites in cell of in- 

 testinal epithelium of mite (E); a young trophozoite and a schizont in 

 intestinal epithelium of lizard after ingestion of infected mites (F). G-L. 

 Selenococcidium intermedium, x765 (after Leger and Duboscq): schizont 

 with eight nuclei, before invasion of an intestinal cell in lobster (G); com- 

 pletion of merogony (H); a macrogamelocyte from the intestinal lumen (I); 

 an intracellular macrogametocyte (J); a microgametocyte before invading a 

 gut cell (K); oocyst (L). M. Oocyst of Lankesterella minima, with sporozoites 

 (no sporocysts arc formed); xll25 (after Noller). 



