SPOROZOA, GREGARINIDA 409 



thium rupestre, Columhella rustica, and Conus mediterraneus in 

 European waters. 



The author found in Ostrea virginica and other molluscs in 

 North Carolina, Virginia, and Maryland, this gregarine and was 

 the first to demonstrate on this continent the germination of the 

 spores taken from the infected oysters in the stomach and mid- 

 gut of Panopeus herhsti and Eurypanopeus depressus at the 

 Bureau of Fisheries Biological Laboratory at Beaufort, N. C. in 

 July, 1936. The vermiform sporozoites emerge from the spores in 

 the pyloric chamber of the stomach and more abundantly in the 

 mid-gut of the mud crabs as early as thirty minutes after intro- 

 duction of the infected tissues of the oyster into their mouths. 

 In the brackish water of the middle Chesapeake Bay region of 

 Maryland, the oyster and other molluscs are only shghtly in- 

 fected. The presence of the characteristic spores in oyster tissues 

 is easily demonstrated by addition of 10 per cent sodium hydrate 

 solution to the material on slides. 



Suborder 2 Schizogregarinaria 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. 185). 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, followed by sporogony. Each individual 

 which is now a gametocyte, produces gametes (d-e). Fusion of 

 two gametes follows (/). The zygote develops into a spore contain- 

 ing 1-8 sporozoites (g, a). 



One spore from 2 gametocytes Family 1 Ophryocystidae 



Two or more spores from 2 gametocytes 



Family 2 Schizocystidae (p. 411) 



Family 1 Ophryocystidae Leger et Duboscq 

 Two gametocytes produce one spore; in Malpighian tubules of 

 Coleoptera, gut of Ascidia and coelom of Oligochaeta. 



Genus Ophryocystis Schneider. Schizogony by binary or mul- 

 tiple division; extracellular; schizonts conical, attached to host 

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



