n.inoDON 1 38 1 



recurved ; anterior portion of the hing^e edentulous, posterior 

 lamella elongate, obtuse, narrow and serrate with obtuse tuber- 

 cles ; nacre white, tinged with rose, bluish towards the mar- 

 gins. 



Length 119, height 55, diam. 45 mm. 



Type locality, Mpala, Lake Tanganyika. 

 Camcronia giraudi Bourguignat, Not. Prod., 1885, p. 107. — 



Simpson, Syn., 1900, p. gio. 

 Pliodon (Camcronia) giraudi Gkrmain, Moll. L. Tan., 1908, 



p. 85, figs. 47, 48. 

 Camcronia cliarbonnicri Boujjguignat, L"''n. and Ir., 1886, p. 



83. — Simpson, Sjm., 1900, p. 909. 

 Pliodon (Camcronia) charhonnicri Germain, Moll. L. Tan., 



1908, p. 85, figs. 45, 46. 

 Camcronia lavigeriana Bourguignat, Un. and Ir., 1886, p. 85. 

 Cameronia lavigerina Simpson, Syn., 1900, p. 910. 

 Camcronia lamgcriei Germain, Moll. L. Tan., 1908, p. 87. 



Germain, (1. c), figures the types of giraudi and cliarbon- 

 nicri and considers them synonymous. He also unites with 

 them C. lavigeriana Bgt. as a mutation "characterized by the 

 great development of the rostral part." 



Pleiodon vynckei (Bourguignat). 



Shell oblong, acutely rostrated at the lower posterior ex- 

 tremity, somewhat incurved in the middle of the basal margin ; 

 thick, opaque, shining; quite heavily striate; black, brown 

 towards the umbones ; nacre pale rose-color, whitish and very 

 iridescent at the margins ; valves gaping at both ends, greatly 

 inflated, especially in the umbonal region; dorsal margin 

 curved ; anterior end rounded ; basal margin straight ; poste- 

 rior end arcutely rostrate : umbones anterior, prominent, much 

 inflated, but laterally compressed anteriorly ; cardinal tooth 

 thick, nearly obsolete ; lateral tooth strong, elongate, thick, 

 serrate. 



Length 134, height 61, diam. 50 mm. 



Type locality. Lake Tanganyika. 

 Cameronia vynckei Bourgi'ignat, Un. and Ir., 1886, p. 81. 

 Camcronia zynckii Simpson, Syn., 1900, p. 910. 



