PERITRICHA 859 



P. socialis (Gruber) (Fig. 365, j). Lorica about 100/t long; often in 

 groups; salt water. 



Genus Platycola Kent. Body similar to that of Vaginicola; but 

 lorica always decumbent and attached throughout one side to its 

 fulcrum of support; fresh or salt water. Many species. 



P. longicollis K. (Fig. 365, k). Lorica yellow to brown when older; 

 about 126^ long; fresh water. 



Family 2 Lagenophryidae Butschli 



Genus Lagenophrys Stein. Lorica with flattened adhering surface, 

 short neck and convex surface; "striped body" connects body with 

 lorica near aperture; attached to fresh or salt water animals. Many 

 species (Swarczewsky, 1930). Biology (Awerinzew, 1936). 



L. vaginicola S. (Fig. 365, 1). Lorica 70/* by 48/*; attached to caudal 

 bristles and appendages of Cyclops minutus and Canthocamptus sp. 



L. patina Stokes (Fig. 365, m). Lorica 55/* by 50/*; on Gammarus. 



L. labiata S. (Fig. 365, n). Lorica 60/* by 55/*; on Gammarus. 



Suborder 2 Mobilia Kahl 



Family Urceolariidae Stein 



Genus Urceolaria Lamarck. Peristome more or less obliquely 

 placed; external ciliary ring difficult to see; horny corona of attach- 

 ing disk with obliquely arranged simple teeth without radial proc- 

 esses; commensal. A few species. Morphology (Wallengren, 1897). 



U. mitra (Siebold) (Fig. 366, a). 80-140/* long; on planarians. 



U. paradoxa (Claparede and Lachmann) (Fig. 366, b). 70-80/* 

 in diameter; colonial forms; in the respiratory cavity of Cyclostoma 

 elegans. 



U. karyolobia Hirshfield. 45-50/* in diameter, 20-30/* high; mac- 

 ronucleus lobate and conspicuous; in the mantle cavity of limpets, 

 Lottia gigantea and Acmaea spp. (Hirshfield, 1949). 



Genus Trichodina Ehrenberg. Low barrel-shaped; with a row of 

 posterior cilia; horny ring of attaching disk with radially arranged 

 hooked teeth; commensal on, or parasitic in, aquatic animals. Several 

 species (Mueller, 1932, 1937). Structure (Wallengren, 1897a); bi- 

 ometry (Faure-Fremiet, 1943). 



T. pediculus (Miiller) (Fig. 366, c). A shallow constriction in mid- 

 dle of body; 50-70/* in diameter; on fish. Those found on Hydra and 

 on the gills of Necturus and Triturus larvae are probably this species 

 -(Fulton, 1923). Reproduction (Cavallini, 1931). 



T. urinicola Fulton (Fig. 366, d). 50-90/* long; teeth 28-36; in 



