54 



PROTOZOA 



Family 3. CHLAMYDODONTIDAE. 



Ovoid or kidney-shaped Infusoria with the mouth usually some dis- 

 tance from anterior end; gullet specially modified to swallow food of 

 large size: about 11 genera. 



1. Nassula Ehrenberg. Body ovate or cylindrical; mouth between 

 middle and anterior end; gullet armed with rods or with a membrane: 

 8 species; in fresh and salt water. 



N. ornata Ehr. Body nearly circular, usually with brightly colored 

 spots; gullet with rods; length .2 mm.: in fresh water. 



N. macrostoma Cohn (Fig. 84). Body nearly circular, with brightly 

 colored spots; gullet with a membranous lining; length .05' mm.: 

 marine; Woods Hole. 



2. Chilodon Ehrenberg. Body flattened, with convex dorsal side; 



Fig. 84 Fig. 85 Fig. 86 



Fig. 84 — Vassula macrostoma (Calkins). Fig. 85 — Chilodon cucuUulus (Calkins). 

 Fig. 86 — Frontonia leucas (Calkins). 



mouth at or in front of middle of body; gullet armed with rods: 

 6 species; in fresh and salt water. 



C. cucullulus (0. F. Miiller) (Fig. 85). Length .1 mm. or less; 

 body ovoid; forward end bent to the left: in fresh and salt water. 



Family 4. CHILIFERIDAE. 



Mouth never behind the middle and always open, with an undulating 

 membrane on the edge of it or in the slightly developed gullet: 

 9 genera. 



Key to the genera of Chili feridae here described : 



a^ Long ventral furrow leading back from the mouth 1. Frontonia 



fla No such furrow. 



6, Caudal bristle present .3. Uronema 



&2 No bristle. 



Ci Body oval, symmetrical 2. Colpidium 



Cj Body rounded dorsally, straight ventrally 4. Colpoda 



1. Frontonia Ehrenberg, Body large, ellipsoid or elongate and 

 contractile and colorless, or green or brown, with mouth near forward 



