1030 NODULARIA 
one-half times as long as the anterior, very high; beaks small, 
somewhat incurved, very tuberculate; dorsal edge blunt; lig- 
ament 4.75 mm. long; in the right valve, two strong cardinal 
teeth, quite long (4 mm.), very stout, subequal and well curved 
and a single, long lateral, at first straight, but curved in the 
last third, high and sharp; in the left valve, one very large 
cardinal, decidedly cleft under the beak, (the cleft part has the 
form of a triangular tooth made of four denticles in the form 
of triangular prisms united at the base), and two, long, ele- 
vated laterals, the lower the larger ; anterior muscular impres- 
sions irregularly oval, very deep, especially near the inner side, 
posterior moderate, pallial line weak. 
Shell solid, rather thick, slightly shining, coffee-colored, be- 
coming yellowish-chestnut near the ventral margin; lines of 
growth fine, quite regular, subequal; some chevrons and tu- 
bercles well rounded and prominent near the beaks; nacre 
white, a little milky, quite iridescent. 
Length 18.5, height 14.5, diam. 9.5 mm.’ (Germain). 
Type locality, N’Guigmi, Lake Tchad. 
Unio (Nodularia) nguigmiensis GERMAIN, Bull. Mus. Nat. 
Hist., 1909, p. 540, fig. 40. 
This little species is quite distinct from Unio (Nodularia) 
lacoimt Germain and its numerous varieties. It is easily dis- 
tinguished by its round, subpentagonal form, more central 
beaks, peculiar character of the hinge and, finally, by the more 
solid shell.” 
NopULARIA FOULADOUGOUENSIS (Jousseaume). 
Shell irregularly elliptical, somewhat inflated, inequilateral, 
subsolid; beaks but slightly full or elevated; anterior end 
rounded, decidedly cut away below; base lightly curved, quite 
full behind the middle, behind this inflation it is obliquely trun- 
cated to the posterior point; dorsal outline a little arched ; 
dorsal slope obliquely subtruncated; posterior ridge rounded, 
ending behind in a somewhat drawn out, but blunt, point about 
‘on the median line; surface with granulous, somewhat zigzag- 
