1344 SPATHA 



ly all denuded in an adult state, the young shell is rose-tinted ; 

 the old shells are bluish : nacre pearly, rose-tinted, bluish in the 

 cavities. 



Length 46, height 23, diani. 12 mm. 



Upper Senegal ; Niger River. 

 Mutelina complanata Jousseaume, Bull. Soc. Zool. de Fr., XI, 



1886, p. 489, pi. XIII, figs. I, 117. — Germaix, Arch. Zool. Exp. 



et. Gen., (5), I, 1909, p. 57. 

 Spatha complanata Simtson, Syn.. 1900, p. 900. 



I have never seen this species, which is formed something 

 like .S". dahomeyensis. According to Jousseaume it has the 

 aspect of Psammobia vcspertina. This appearance and the al- 

 most entire want of epidermis in an adult state would seem 

 to be good distinguishing characters. 



Var. ciirta (Germain). 



"Shell less elongated, the posterior region being in propor- 

 tion to the anterior very much shorter and higher than in the 

 typical form ; dorsal margin slightly convex, notably ascending 

 and not subrectilinear : ventral margin decidedly convex. 



Length 26, height 15.5, diam. 8 mm." (Germain). 



Type locality, the Chari and the Bangoran. 

 Mutelina complanata var. carta Germain, Bull. Mus. Hist. 



Nat., 1907, p. 68 ; TAfrique Cent. Fr., 1909, p. 574. 



"As in the type the shell is very compressed, thin, epidermis 

 yellow, tinted with rose, passing to cafe au lait towards the 

 beaks and to greenish-yellow towards the margins ; the lines 

 ■ of growth are noticably stronger and more irregular." 



Subgenus Moncetia Bourguignat, 1885. 



Moncetia BorRGuiGNAT, Esp. ()uk., 1885, p. 34. 



Shell long-elliptical, inequilateral, compressed, thick, som- 

 ber-colored ; beaks compressed, smooth, sharp ; hinge with a 

 tubercular eminence near the beak of the right valve, with two 

 internal ligaments and three groups of muscular impressions. 

 (Bourguignat). 



Animal unknown. 



Type, Moncetia anccyi Bourguignat. 



