COCCIDIA 



575 



studied its life cycle and found that during microgametogenesis and 

 sporogony, 6 chromosomes occur. She added that meiosis occurs in 

 the zygote which is the only diploid stage as in Aggregata eberihi. 



Genus Pseudoklossia Leger and Duboscq. Anisogamy and spo- 

 rogony in the kidney of marine mussels; oocyst or zygote produces 

 numerous spores; spore with 2 sporozoites; no residual body; schi- 

 zogony unknown, in another host (Leger and Duboscq, 1915, 1917). 



P. pectinis L. and D. (Fig. 247, c). In kidney of Pecten maximus 

 in France; association of 2 sporozoites which are 3.5/z in diameter. 



Fig. 247. a, b, Spores of Merocystis kathae, X1000 (Foulon); c, Pseudo- 

 klossia pectinis, two sporozoites of a spore, X1470 (Leger and Duboscq); 

 d-k, Eimeria stiedae (d, a trophozoite; e, host cell with three trophozoites; 

 f, g, schizogony; h, macrogametocyte, X1270 (Hartmann) ; i-k, oocysts, 

 X830 (Wasilewski)); 1, m, E. perjorans, X750 (Perard); n, E. faurei, 

 X800 (Wenyon). 



Genus Caryotropha Siedlecki. Both schizogony and sporogony 

 take place in a host. One species. 



C. mesnili S. In coelom (in floating bundles of spermatogonia) of 

 the polychaete, Polymnia nebulosa; schizogony in bundle of sper- 

 matogonia, in which cytomeres with 10-16 nuclei and then mero- 

 zoites are formed; schizogony repeated; gametocytes undergo de- 

 velopment also in the same host cells; microgametes become set 

 free in coelom, where union with macrogametes takes place; each 

 oocyst forms about 16 spores; spore with usually 12 sporozoites; 

 cysts are extruded with the reproductive cells of the host worm. 



