SPOROZOA, GREGARINIDA 



413 



Fig. 187. a-c, Selenidium 'potamillae (a, X420; b, cyst with spores, 

 X330; c, spore) (Mackinnon and Ray); d-f, Mero selenidium keilini 

 (d, sporadin, X670; e, f, different views of spore, X930) (Mackinnon 

 and Ray); g-j, Machadoella iriatomae (g, a schizont, X1420; h, i, a 

 single and associated gamonts, X710; j, spore, X1920) (Reichenow); 

 k, 1, Syncystis mirahilis: k, a cyst, X470 (Steopoe) ; 1, spore (Schneider); 

 m, Mattesia dispora, X1480 (Naville), n, Lipotropha macrospora, X800 

 (Keilin). 



Genus Meroselenidium Mackinnon et Ray. Schizogony intra- 

 cellular, initiated by formation of small masses which give rise 

 to merozoites; about 20 spores from a pair of gametocytes; spores 

 with numerous sporozoites. One species. 



M. keilini M. et R. (Fig. 187, d-f). Large schizonts about 150/^ 

 by 30m; sporadins free in gut 200-300ju by 40-70^; paired gameto- 

 cytes 85m by 40/x; spores 26-28/x by 14-1 6At, bivalve (?), trans- 

 verse ridges, with many sporozoites; in gut of Potomilla renifor- 

 mis. 



Genus Machadoella Reichenow\ Nematode-like, rigid; simple 

 rounded anterior end; thick pellicle, longitudinally striated; schi- 

 zogony in vermiform stage; head to head association of gameto- 

 cytes; cysts with 3-6 spores, each with 8 sporozoites. 



