PERITRICHA 625 



which closes lorica when organism contracts; fresh or salt water. 

 Many species. 



P. affinis K. (Fig. 283, h, i). Lorica about 85/i long; in marsh 

 water. 



P. socialis (Gruber) (Fig. 283, j). Lorica about lOO^u long; often 

 in groups; salt water. 



Genus Platycola Kent. Body similar to that of Vaginicola; 

 but lorica always decumbent and attached throughout entire one 

 side to its fulcrum of support; fresh or salt water. Many species. 



P. longicollis K. (Fig. 283, k). Lorica yellow to brown when 

 older; about 126/^ long; fresh water. 



Family 2 Lagenophryidae BiitschU 



Genus Lagenophrys Stein. Lorica with flattened adhering sur- 

 face, short neck and convex surface; "striped body" connects 

 body with lorica near aperture; attached to fresh or salt water 

 animals. Many species. 



L. vaginicola S. (Fig. 283, I). Lorica 70^1 by 48/i; attached to 

 caudal bristles and appendages of Cyclops minutus and Cantho- 

 camptus sp. 



L. patina Stokes (Fig. 283, m). Lorica 55/i by 50 fx; on Gam- 

 marus. 



L. lahiata S. (Fig. 283, )i). Lorica 60^1 by 55^; on Gammarus. 



Suborder 2 Mobilia Kahl 

 Family Urceolariidae Stein 



Genus Urceolaria Lamarck. Peristome more or less obhquely 

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

 attaching disk with obliquely arranged simple teeth without 

 radial processes; commensal. A few species. 



U. niitra (Siebold) (Fig. 284, a). 80-140/x long; on planarians. 



U. paradoxa (Claparede et Lachmann) (Fig. 284, h). 70-80/i 

 in diameter; colonial forms; in respiratory cavity of Cyclostoma 

 elegans. 



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

 of posterior cilia; horny ring of attaching disk with radially ar- 

 ranged hooked teeth; commensal on, or parasitic in, aquatic 

 animals. Several species. 



T. pediculus (Miiller) (Fig. 284, c). A shallow constriction in 

 middle of body; 50-70^ in diameter; on Hydra, amphibian larvae 



