276 HANDBOOK OF PROTOZOOLOGY 



Pfeifferinella ellipsoides Wasielewski (Fig. \\S, d). In the 

 liver of Planorhis cornua. 



Pfeifferinella impudica Leger and HoUande (Fig. 115, e). 

 In the liver of the land snail, Limax marginatus. 



Genus Barrouxia Schneider. The zygote develops into an 

 oocyst, in which numerous spores, each containing a single 

 sporozoite, develop. The spore membrane may be uni- or bi- 

 valve and a caudal prolongation may occur in some species. 



Barrouxia ornata Schneider (Fig. 115,/). In Nepa cinerea. 

 The spherical oocyst measures 34 to 37 microns; the spores 

 20 microns by 10 microns. 



Genus Lankesterella Labbe. Typically parasites of the en- 

 dothelial cell of cold-blooded vertebrates. Development is 

 not completely known. 



Lankesterella minima (Chaussat) (Fig. 115, g). The frog 

 acquires infection through the introduction of the sporozoites 

 by the leech. The sporozoites make their way into the blood 

 capillaries of various organs. There they apparently enter the 

 endothelial cells. Schizogony produces numerous merozoites 

 which bring about infection of many host cells. Ultimately 

 macro- and micro-gametocytes are formed; anisogamy produces 

 zygotes. The zygotes transform themselves into oocysts, in 

 which a number of sporozoites develop. These sporozoites are 

 set free upon disintegration of the oocyst wall in the plasma 

 and enter the erythrocytes (Noller). 



Genus Cryptosporidium Tyzzer. Lumen-dwelling form. The 

 oocyst contains four sporozoites. Exceedingly minute organ- 

 isms. 



Cryptosporidium muris Tyzzer. In the stomach lumen of 

 the white mouse. 



Cryptosporidium parvum Tyzzer. In the intestine of the 

 mouse. 



Suborder 2 Adeleidea Leger 



The Adeleidea are on the whole similar to the Eimeridea in 

 their habitat and development. But the schizonts develop 

 into micro- and macro-gametocytes which become attached to 

 each other in pairs during the course of the development into 

 gametes (Fig. 116,/, g). Each microgametocyte produces a few 

 microgametes {h). The zygote divides into numerous sporo- 



