NO. 1205. SYNOPSIS OF THE NAT ADES— SIMPSON. 907 



hinge edentulous, filiform, with two ligaments, one internal, the other 

 external; there are three groups of muscular impressions and several 

 dorsal scars running in a row from the beak forward and downward; 

 upper border of the left valve projecting over that of the right, forming 

 a sinuous wing. 

 Animal unknown. 



BRAZZiEA ANCEYI Bourguignat. 



* Brazzcea anceyi Bourguignat, Esp. Ouk. et Tan., 1885, p. 33; "Icon., 1888, pi. 



xxviii, figs. 1-4. — * VON Martens, Bescli., 1807, p. 258. 

 "" Brazzcea eximia Bourguignat, Un. et Ir. Tan., 1886, p. 57; * Icon., 1888, pi. 



XXIX, fig. 5. ■ " 



Lake Tanganyika. 



BRAZZJEA BOURGUIGNATI Bourguignat. 



'* Brazzcea bourgtiignati Bourguignat, Uu. et Ir. Tan., 1886, p. 58; 'Icon., 1888, 

 pi. XXVIII, figs. 5, 6. 



Lake Tanganyika. 



BRAZZMA ELONGATA Bourguignat. 



"^ Brazzcea elo7i(iataBoVRGViGisiAT,\Jn. et Ir. Tan., 1886, p. 51; * Icon., 1888, pi. 

 XXIX, figs. 2, 3. 



Lake Tanganyika. 



BRAZZJEA COULBOISI Bourguignat. 

 * Brazzce,a coulboisi Bourguignat, Uu. et Ir. Tan., 1886, p. 50; 'Icon., 1888, pi. 



XXIX, fig. 1. 



Lake Tanganyika. 



BKAZZJEA VENTROSA Bourguignat. 



*' Brazzcva veritrosa BOVRGVIGNAT, Uu. et Ir. Tan., 1886, p. 45; *Icon., 1888, pi. 

 XXIX, fig. 4. 



Lake Tanganyika. 



The following are unfigured species: 



Brazzdia randabeli Bourguignat, Un. et Ir. Tan., 1886, p. 46. 

 Brazza'a moineti Bourguignat, Un. et Ir. Tan., 1886, p. 47. 

 Brazzcea jourdyi Bourguignat, Un. et Ir. Tan., 1886, p. 48. 

 Brazzma cliarbonnieri Bourguignat, Uu. et Ir. Tan., 1886, p. 52. 

 Brazzcea lavigerina Bourguignat, Un. et Ir. Tan., 1886, p. 53. 

 Brazzcea bridouxi Bourguignat, Un. et Ir. Tan., 1886, p. 54. 

 Brazzcea neweombiana Bourguignat, Un. et Ir. Tan., 1886, p. 55. 



All from Lake Tanganyika. 



Genus PLEIODON Conrad, 18S4. 

 (Type, Pleiodon ovatiis Swainson.) 

 Pleiodon Conrad, Jl. Ac. N. Sci. Phila., VII, 1834, p. 178. 



Shell elliptical, inflated, solid, with a rounded posterior ridge, and 

 full, smooth beaks; epidermis smooth, shining, generally rayless ; hinge 



1 Said by Bourguignat to be of Jonbert in litt. 



