HOLOTRICHA 617 



U. marina D. (Fig. 291, e). 30-50/i long; in salt water in decaying 



U. pluricaudatum Noland (Fig. 291, /, g). Body appears to be 

 twisted in dorsal view, due to a spiral depression that runs obliquely 

 down toward cytostome; with about 8 caudal cilia; in salt water; 

 Florida. 



Genus Homalogastra Kahl. Broad fusiform; furrows spiral to left; 

 a long caudal cilium; a group of cilia on right and left side of it; 

 macronucleus spherical, anterior; contractile vacuole posterior; in 

 fresh water. 



H. setosa K. (Fig. 291, h). About SOn long; fresh water. 



Genus Stokesia Wenrich. Oblique cone with rounded angles; flat 

 anterior surface uniformly ciliated; with peristome bearing zones of 

 longer cilia, at the bottom of which is located the cytostome; a 

 girdle of longer cilia around the organism in the region of its greatest 

 diameter; pellicle finely striated; with zoochlorellae; trichocysts; 

 free-swimming; in freshwater pond. One species. 



S. vernalis W. (Fig. 291, i,j). 100-160/x in diameter; macronucleus; 

 2-4 micro nuclei; fresh water. 



Family 2 Ophryoglenidae Kent 



Genus Ophryoglena Ehrenberg. Ellipsoidal to cylindrical; ends 

 rounded or attenuated; preoral depression in form of *6' due to an 

 ectoplasmic membrane extending from the left edge, cilia on the 

 right edge; cytostome deep-seated; 1 (or 2) contractile vacuole with 

 long radiating canals, opens through pores on right ventral side; 

 macronucleus of various forms with several endosomes; a micro- 

 nucleus; fresh or salt water or parasitic. Many species. 



0. collini Lichtenstein (Fig. 291, k). Pyriform; macronucleus 

 horseshoe-shape; 200-300/i by 120-230|u; in the caecum of Baetis 

 larvae. 



0. parasitica Andre. Ovoid; dark; micronucleus (?); 170-350ai by 

 180-200iLt; in the gastro vascular cavity of Dendrocoelum lacteum. 



0. pyriformis Rossolimo (Fig. 291, I). Flask-shape; 240-300iu long; 

 in the gastrovascular cavity of various Turbellaria. 



0. intestinalis R. (Fig. 291, m). Up to 1.5 mm. by 450-500^; small- 

 est 60/x long; in the gastrovascular cavity of Dicotylus sp. 



0. atra Lieberkiihn. Oval, posterior end broadly rounded; 300- 

 500/x long; grayish; filled with globules; cytostome near anterior end; 

 macronucleus elongated; a contractile vacuole; trichocysts; stagnant 

 fresh water. 



