560 PROTOZOOLOGY 



hosts: Mytilus galloprovincialis, M. minimus, Lasea rubra, Cardita 

 calyculata, Chiton caprearum, Trochocochlea turbinata, T. articulata, 

 T. mutabilis, Phorcus richardi, Gibbula divaricata, G. rarilineata, G. 

 adamsoni, Pisania maculosa, Cerithium rupestre, ColumbcUa rustica, 

 and Conus mediterraneus in European waters (Hatt, 1931). 



N. ostrearum Prytherch. Sporadins in syzygy in the mud crabs, 

 Panopeus herbsti and Eurypanopeus depressus, 220-342 n; cysts 80- 

 190^ in diameter; gymnospores 4/* in diameter; spores produced in 

 the oyster, Ostrea virginica, 16^ by 11-12/z (Prytherch, 1940). Lan- 

 dau and Galtsoff (1951) showed that the organism is widely dis- 

 tributed among the oysters along the Atlantic and Gulf coasts, but 

 found no evidence to suppose that the organism is destructive to the 

 host mollusc. 



N. panopei Ball. Sporadins up to 210/x by 14/z; protomerite about 

 1/15 the body length; epimerite on young individuals only; syzygy 

 often multiple, as in other species; cysts 88 ^ by 74^, free in the 

 lumen or attached to the wall of the hind-gut; gymnospores about 

 6.5^ in diameter; in the gut of Panopeus herbsti and P. occidentalis ; 

 in Bermuda. Molluscan host unknown (Ball, 1951). 



Suborder 2 Schizogregarinina Leger 



The schizogregarines are intestinal parasites of arthropods, an- 

 nelids, and tunicates. When the spore gains entrance to the di- 

 gestive tract of a specific host through mouth, it germinates and 

 the sporozoites are set free (Fig. 239). These sporozoites develop 

 into trophozoites either in the gut-lumen or within the host cells, 

 and undergo schizogony (c), which may be binary or multiple fis- 

 sion or budding. The fully grown trophozoites become paired as 

 in Eugregarinina and encyst, in which condition they undergo 

 sexual reproduction. Each individual which is now a gametocyte 

 produces gametes (d-e). Fusion of two gametes follows (/). The 

 zygote develops into a spore containing 1-8 sporozoites (g, a). 



One spore from 2 gametocytes Family 1 Ophryocystidae 



Two or more spores from 2 gametocytes 



Family 2 Schizocystidae (p. 562) 



Family 1 Ophryocystidae Leger and Duboscq 



Two gametocytes produce one spore; in Malpighian tubules of 

 Coleoptera, gut of Ascidia and coelom of Oligochaeta. 



Genus Ophryocystis Schneider. Multiplication by binary or mul- 

 tiple division; extracellular; trophozoites conical, attached to host 

 cells by pseudopods; a single spore in a pair of spheroidal gameto- 



