692 PROTOZOOLOGY 



L. vaginicola S. (Fig. 325, 1). Lorica 70^ by 48/x; attached to caudal 

 bristles and appendages of Cyclops minutus and Canthocamptus sp. 

 L. patina Stokes (Fig. 325, w). Lorica 55/i by 50^; on Gammarus. 

 L. labiata S. (Fig. 325, n). Lorica 60/i by 55/i; 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. 



U. mitra (Siebold) (Fig. 326, a). 80-140^ long; on planarians. 



U. paradoxa (Claparede and Lachmann) (Fig. 326, 6). 70-80^ 

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

 elegans. 



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. 



T. pediculus (Miiller) (Fig. 326, c). A shallow constriction in mid- 

 dle of body; 50-70^1 in diameter; on Hydra, amphibian larvae and 

 probably fish. Those found on Hydra and gills of Necturus and Tri- 

 turus larvae are probably identical (Fulton, 1923). 



T. urinicola Fulton (Fig. 326, d). 50-90/i long; teeth 28-36; in 

 urinary bladder of a moribund Bufo sp. and Triturus. 



T. sp. Diller (Fig. 326, e). 30-40m in diameter; on the skin and gills 

 of frog and toad tadpoles. 



Genus Cyclochaeta Jackson. Saucer-form; peristomal surface 

 parallel to the basal disc ; upper surface with numerous fiat wrinkles ; 

 basal disc composed of cuticular rings, velum, cirri, and membranel- 

 lae; commensal on, or parasitic in, fresh or salt water animals. Sev- 

 eral species. MacLennan (1939) made a careful study of two species. 



C. spongillac J. (Fig. 326,/). About 60/x in diameter; in interstices 

 of Spongilla fluviatilis. 



C. domerguei Wallengren (Fig. 326, g, h). 23-56^ in diameter; 

 about one-fifth high; 18-25 denticles, each with a narrow slightly 

 curved spine; outer cuticular ring more finely striated than inner 

 ring; cirri longer than membranellae (MacLennan); on fresh water 

 fishes. 



