Pr.FJODON 1383 



straight, slightly incurved in the middle ; anterior end short ; 

 posterior end very long, almost three and one-half times as 

 long as the anterior, terminating in a short, oblique point ; 

 beaks quite obtuse, much depressed ; muscular impressions 

 deep; hinge irregularly dentate, denticulations stronger pos- 

 teriorly. Epidermis dark chestnut, passing into black towards 

 the anterior and ventral margins ; lines of growth moderate 

 and irregular; nacre very bright rose-salmon, very iridescent. 



Length 105, height 43.5 at 39 mm. from the beaks, diam. 28 

 mm." (Germain). 



Type locality. Lake Tchad. 

 Pliodon (Cameronia) Imrdeleti Germain, Bull. Mus. Hist. 



Nat., 1905, p. 489 ; Ibid, 1906, p. 56. fig. 2 ; I'Afrique Cent. 



Fr., 1907, p. 577, fig. 99. 



Var. niolli Germain. 



"This variety differs from the type : By its more regularly 

 elongate oval shape ; by its dorsal margin being nearly straight, 

 slightly ascending, and nearly parallel to the ventral margin, 

 (in the typical form the dorsal and ventral margins are very 

 divergent) ; by the less decidedly truncate posterior end, etc. 



Length 105, height at 44 mm. from the beaks 38, diam. 26 

 mm." (Germain). 



Type locality. Lake Tchad. 

 Pliodon f Cameronia) hardeleti var. molli Germain, Bull. Mus, 



Hist. Nat., 1906, p. 58, fig. 3 ; I'Afrique Cent. Fr., 1907, p. 



578, fig. loo.- 



The following are unfigured species of Cameronia: 



Cameronia anceyi Bourguignat, Esp. Ouk., 1885, p. 30. 

 Cameronia complanata Bourguignat, Un. and Ir., 1886, p. 76. 

 Cameronia drontauxi Bourguign.at, Un. and Ir., 1886, p. 84. 

 Cameronia guillemeti Bourguignat, Un. and Ir., 1886, p. 72. 

 Cameronia jouberti Bourguignat, Un. and Ir., 1886, p. 88. 

 Cameronia locardiana Bourguignat, Un. and Ir., 1886, p. 78. 

 Cameronia marinniana Bourguignat, Esp. Ouk., 1885, p. 28. 

 Cameronia mabilliana Bourguignat, Un. and Ir., 1886, p. 86. 

 Cameronia moincti Bourguignat, Un. and Ir., 1886, p. 89. 



