BRAZZ.EA 1373 



Bra.z.^(ca bourgiiignati Uourguignat, Un. and Ir. Tan., i^ 



p. 58; Icon., 1888, pi. XXVIII. figs. 5, 6. — Simpson, Syn., 



1900, p. 907. 



This seems to be one of the few Naiades, whose diameter is 

 greater than the height. The beaks of this species are elevated 

 above the dorsal line and are much more swollen than in B. 

 anccyi, and the shell is more elongated. 



Said by Bourguignat to be of Joubert in lift. 



Brazz.^a i:longata Bourguignat. 



Shell irregularly long elliptical, somewhat inflated, subsolid, 

 opake, inequilateral, bihiant ; beaks full ; dorsal outline curved ; 

 anterior end narrowed, rounded, slightly angled above; base 

 line much and evenly curved ; posterior ridge well developed, 

 decidedly double, ending in a well-marked biangulation be- 

 hind, the region above it very slopingly truncate, surface con- 

 centrically striate, subviolaceous chestnut, becoming pale yel- 

 lowish white or violaceous at the beaks ; nacre whitish, the 

 margins pale violet. 



Length 78, height 42. diam. 34 mm. 



Lake Tanganyika. 

 Brazzffa elongata Bourguignat, Un. and Ir. Tan., 1886, p. 51 ; 



Icon., 1888, pi. XXIX, figs. 2, 3. — Simpson, Syn., 1900. p. 



907. 



Less inflated and more evenly elliptical than the preceding 

 species. The color externally and internally is different. 



Brazz^a couiyBOisi Bourguignat. 



Shell somewhat obovate, subinflated, scarcely inequilateral) 

 subsolid ; dorsal outline arched, most produced at the rather 

 full beaks ; anterior end narrowed, rounded ; base curved, quite 

 full behind the middle ; posterior ridge double, ending in a 

 biangulation at and below the median line ; dorsal slope ob- 

 liquely truncate ; surface subopake, violet-blackish ; nacre splen- 

 did violet wine-color, with metallic, silvery iridescence. 



Length 62, height 44. diam. 28 mm. 



Lake Tanganyika. 



