524 



PROTOZOOLOGY 



Family 1 Unicapsulidae Kudo 



Genus Unicapsula Davis, Spherical spore with 1 polar capsule; 

 shell-valves asymmetrical; sutural line sinuous; histozoic in marine 

 fish. One species. 



U. muscularis D. (Fig. 248). Spore about 6m in diameter; 2 uni- 

 nucleate sporoplasms; in muscle fibers of halibut; Pacific coast of 

 North America; the cause of the "wormy" halibut (Davis). 



Fig. 249. a, Mijxoproteus cordiformis, X 1000 (Davis) ; b, Wardia ovino- 

 cua, X1330 (Kudo); c, Sphaerospora polymorpha, XlOOO (Davis); d-i, S. 

 tincae (d, external appearance of a heavily infected young tench; e, in- 

 ternal appearance, X§; f, mature pansporoblast; g, h, two spores; i, germi- 

 nation of spore, XlOOO) (L^ger); j, k, Sinuolinea dimorpha (j, trophozoite 

 with three gemmules, X420; k, a spore, X930) (Davis); 1, m, Chloro- 

 myxum leydigi (1, X500; m, XlOOO) (Thelohan); n, C. trijugum, X1130 

 (Kudo). 



Family 2 Sphaerosporidae Davis 

 Genus Sphaerospora Thelohan. Spore spherical or subspherical; 

 sutural line straight; 2 polar capsules at anterior end; coelozoic or 

 histozoic in marine or freshwater fishes. 



