45] STUDIES ON GREGARINES—KAMM 45 



GANYMEDES Huxley 1910:55 



A possible fixation organ at interior end, consisting of a motile stalked 

 sphere. Cup at posterior end which fits into ball of a satellite. No sep- 

 tum, no true epimerite. Typical gregarinoid encystment, cysts spherical. 

 Alimentary tract of Crustacea. 



Huxley offers the hypothesis that this gregarine lies between the 

 polycystids and the monocystids and creates for it a new family, Gany- 

 medidae. Since his studies were made only upon fixed material and all 

 characters of this very unusual parasite are unknown, I think the rank of 

 a new family is hardly justifiable and prefer to consider it among the 

 Genera of Uncertain Position. 



GANYMEDES ANASPIDIS Huxley Type Species 

 [Figure 89] 

 1910 Ganymedes anaspidis Huxley 1910: 155 



1913 Ganymedes anaspidis Ellis 1913: 264 



Characters of the genus. Sporonts in pairs, elongate cylindrical, 

 maximum length 200ai, width 120/i. Average size 250/i to 300/* by 17 fi 

 to 20/i. Nucleus large, ellipsoidal, one large karyosome. Cysts spherical, 

 lOO/i in diameter. 



Anterior end of protomerite a "distinct stalked sphere," 8 to 10/* across. 

 Protoplasm of anterior end highly specialized, posterior end a socket into 

 which fits the "ball" of another individual, during the associative period. 



Intestine and pyloric caeca of Anaspides tasmaniae (Thompson). 



Taken on the Island of Tasmania. 



Species of Uncertain Position 



1839: ? 

 1848: 196 

 1848: 35 

 1859: 735 

 1863: 95 

 1886: 236 

 1895:60 

 1899: 36 

 1903: 330 



Epimerite present. Sporonts 425/* in length, long-ovoidal. 



Intestine and ? coelom of Gammarus pulex. 



von Siebold described Didymophyes longissima from the same host, 

 considering it a second form of the same species. In the same paper. 



