590 PROTOZOOLOGY 



ciliary rows; some 7 dorsal bristles; widely distributed in various 

 freshwater bodies; several varieties. 



C. cyprini (Moroff) (Fig. 279, h). 50-70/x by 30-40m; in the integu- 

 ment and gills of cyprinoid fishes ; the organism, if freed from the host 

 body, dies in 12-24 hours. 



C. longiphanjnx Kidder and Summers. 17-21^ (average 19^) long; 

 cytopharynx long, reaches posterior end; ectocommensal on amphi- 

 pods, Talorchestia longicornis and Orchestia palustris; Woods Hole. 



C. hyalina K. and S. 40/i (36-47^) long; ectocommensal on Or- 

 chestia agilis; Woods Hole. 



C. rotunda K. and S. 29/x (27-34/i) long; ectocommensal on Or- 

 chestia agilis; Woods Hole. 



Genus Allosphaerium Kidder and Summers. Oval; right side con- 

 cave, left side more or less fiat; body highly flattened; arched dorsal 

 surface devoid of cilia; ventral surface slightly concave with 12-27 

 ciliary rows; right and left margin of ventral surface with a pellicu- 

 lar fold; cytostome anterior-ventral, oval or irregular, surrounded by 

 ridge on posterior border, extending to left margin; 3 groups of 

 ciliary membranes extending out of cytostome; macro nucleus oval, 

 central or anterior; a micro nucleus; 2 (or 1) contractile vacuoles; a 

 refractile spherule regularly present in posterior portion of endo- 

 plasm; ectocommensal en the carapace and gills of amphipods. 



A. palustris K. and S. (Fig. 279, i). 46-59m long; 27 ventral ciliary 

 rows; on Orchestia palustris and Talorchestia longicornis; Woods 

 Hole. 



A. sulcatum K. and S. 24-32/ilong; 12 ciliary rows; on the carapace 

 of Orchestia agilis and 0. palustris; Woods Hole. 



A. granulosum K. and S. 32-42/i long; rotund; 17 ciliary rows; 

 cytoplasm granulated; on carapace of Orchestia agilis and 0. palus- 

 tris; Woods Hole. 



A. caudatum K. and S. Resembles A. palustris; 35-45)u long; 14 

 cihary rows; 1 contractile vacuole; ectoplasm at posterior end, drawn 

 out into a shelf ; on Orchestia agilis; Woods Hole. 



A. convexa K. and S. 24-36iu long; 17 ciliary rows; on the carapace 

 and gill lamellae of Talorchestia longicornis; Woods Hole. 



Family 4 Pycnothricidae Poche 



Ciliation uniform; ectoplasm thick and conspicuous; a furrow or 

 groove connects the cytostome with the anterior end; parasitic in 

 the alimentary canal of mammals. 



Genus Pycnothrix Schubotz. Large, elongate; with broadly 

 rounded anterior and narrowed posterior end; somewhat flattened; 



