1362 MUTEI.A 



Length 58, height 24, of anterior region 11, of posterior re- 

 gion 48, diam. 12.5 mm/" (Germain). 



Type locahty, Lake Tchad. 

 Mnteiina mahillei var. gaillardi Germain, Bull. Mus. Hist. 



Nat., 1909, p. 477. 



"Compared with Mnteiina niahiilci var. frasi Germain, this 

 shell is distinguished : By its general form ; by its dorsal and 

 ventral margins being parallel and not divergent ; by the pe- 

 culiar form of the anterior region, which is, besides, very 

 much shorter ; by its more rounded posterior region ; and fin- 

 ally 1\v its slightly thicker and much more heavy shell." 



IMi^TEi.A FALKMKENSis (Germain). 



"Shell moderately long, decidedly compressed ; valves thin, 

 fragile, gaping at both ends; dorsal and ventral margins very 

 divergent ; dorsal margin, subrectilinear, decidedly ascending ; 

 ventral margin convex ; anterior region rounded ; posterior 

 region two and one-half times as long as the anterior, re- 

 markably enlarged and terminating in a large beak, placed 

 very high ; beaks small, not prominent ; ligament long and 

 strong ; muscular impressions feeble. 



Length 66, height 32, diam. 13 mm." (Germain). 



Type locality, River Faleme, Senegal. 

 Mutelina faleineensis Germain, Bull. Mus. Hist. Nat.. 1907,. 



p. 67; I'Afrique Cent. Fr., 1907, p. 569, fig. 96. 



Subgenus Pseudomutela Simpson, 1900. 



Pseud ornuiela Stmfson, Syn., 1900, p. 905. 



Shell rather thin, elongate, wide, round and gaping behind, 

 cut awav and gaping at the anterior base ; beaks low ; surface 

 rudelv sulcate ; a series of irregular, nodulous projections ex- 

 tends down the low posterior ridge ; hinge edentulous, with a 

 kind of faint, broken internal ligament, with a wide prismatic 

 streak behind ; muscle scars distinct, united, the anterior pro- 

 tractor, however, separated and irregular; nacre lurid violet, 

 iridescent behind. 



Type, Mycclopus plicatus Sowerby. 



