CNIDOSPORIDIA, MYXOSPORIDIA 653 



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. 



Fig. 281. Unicapsula muscularis (Davis), a, b, infected muscle fibers, 

 X20; c, cross-section of an infected muscle, X190; d, part of a section of 

 an infected muscle, X575; e-h, spores, X2500. 



S. polymorpha Davis (Figs. 280, c; 282, a-e). In the urinary blad- 

 der of toadfish, Opsanus tau and 0. beta. Trophozoites amoeboid 

 with conical pseudopodia; up to 100/x long, the majority being 20-5(V 

 long; plasmotomy; disporoblastic; disporous or polysporous. Spores 

 spheroidal; shell-valves finely striated; polar capsules divergent; 

 fresh spores measure 7. 5-9. 5m by 7-8/*. The trophozoites suffer fre- 

 quently infection by Nosema notabilis (p. 672). Development and 

 hyperparasitism (Kudo, 1944). 



