INFUSORIA 53 



Key to the genera of Trachclinidae liere described: 



ffi Distinct neck region. 

 6i Mouth runs the length of the neck. 



Ci Entire body uniformly ciliated 1. Amphileptus 



C2 Ventral surface only ciliated 2. LiONOTUS 



62 Mouth at base of neck, which is very long 4. Dileptus 



flj No distinct neck region 3. I^xopiiyllum 



1. Amphileptus Ehrenberg. Body often curved, elongate, flattened, 

 with a sharp neck-like forward end; no gullet: 3 species; in fresh and 

 salt water. 



A. gutta Claparede (Fig. 80). Macronuclens double; length .08 mm. 



Fig. so 



Fig. 81 



Fig. 80 — Amphileptus (j!'t''i 

 (Conn) . Fig. 81 — Lionotus ; .«- 

 (iola (Calkins). Fig. H2—Lodo- 

 i)hyUum rostrutum (Conn). 



Fig. 82 



2. Lionotus "Wrzesniowski. Body elongate, tapering to both ends, 

 with a large hump; usually two macronuclei; flattened side only ciliated; 

 anterior end neck-like : 6 species ; in fresh and salt water. 



L. wrzesniowskii Kent. Length .18 mm.: in fresh water. 



L. fasciola (Ehrenberg) (Fig. 81). Body ellipsoid, hinder end 

 conical; length up to .6 mm.: in fresh and salt water; Woods Hole; Cold 

 Spring Harbor. 



3. LoxoPHYLLUM Dujardin. Body flat, with a broad hyaline border; 

 anterior projection slight, turned to the right; trichocysts often in 

 papilla-like groups; nucleus often bead-like: in standing water; 4 

 species; in fresh and salt water. 



L. rostratum Cohn (Fig, 82). Body elongate; 

 length .15 mm.: in fresh water. 



L. setigerum Quennerstedt. Body broad; 1 

 mm. long: in salt water. 



4. Dileptus Dujardin. Body large, elongate, with a long contractile 

 neck, at the base of which is the mouth; numerous contractile vacuoles; 

 nucleus often bead-like : 2 species ; in fresh and salt water. 



D. anser (0. F. Miiller) (Fig. 83). Body striated; length up to 

 1.5 mm.: among algae in fresh water. 



Fig. 83 — Dileptus anser 

 (Conn). 



