242 



TEOCHELM1NTHES 



M. bulla Gosse (Fig. 393). Dorsal plate very high; ventral plate 

 somewhat convex; anterior margin with a notch; .25 mm. long: very 

 common among aquatic plants. 



FAMILY 7. EUCHLANIDAE. 



Large transparent rotifers with a convex dorsal and 

 a flat or slightly convex ventral plate; foot jointed, with 

 2 large, diverging, blade-shaped toes: 2 genera. 



ETICHLANIS Ehrenberg. Lorica oval and flat; eye 

 present: 7 species. 



E. dilatata Ehr. (Fig. 394). Lorica with a pair 

 of lateral flanges projecting from its ventral plate; 

 anterior dorsal margin with a broad gap having a 

 straight bottom; length .3 mm.: often very common in 

 aquatic vegetation. 



FAMILY 8. COLUEIDAE. 



Monostyla bulla 

 (Jennings). 



Head surmounted by an arched shield, appearing in a side view like 

 a hook: 5 genera. 



1. METOPIDIA Ehrenberg. Lorica flattened, usually turtle-like in 

 appearance; usually 2 eyes: 11 species. 



M, lepadella Ehr. (Fig. 395). Lorica oval, without teeth or spines 



Fig. 394 



Fig. 395 



Fig. 396 



Fig. 394 Euchlanis dilatata (Sussw. F. Deut.). Fig. 395 Metopidia lepadella 

 (Sussw. F. Deut.). Fig. 396 Monura colurus (Hudson and Gosse). 



or prominent angles; 2 eyes; ventral plate indented behind; length .08 

 mm. : often abundant among aquatic plants. 



M. acuminata Ehr. Lorica oval, ending behind in a sharp point; 

 length .08 mm.: often common among aquatic plants. 



2. MONURA Ehrenberg. Lorica arched, more or less compressed lat- 

 erally, often open mid-ventrally. 



M. colurus Ehr. (Fig. 396). Length .1 mm.: often common among 

 in the sea, 



