NODULARIA 1035 
squarely subtruncate ; teeth thin, lamellar ; scars shallow ; nacre 
white pearly. 
Length 25, height 16.5, diam. 9.5 mm. 
Lake Tanganyika. 
Unio horei E. A. Smiru, Ann. and Mag., VI, 1880, p. 429; 
Pry Zcok. Soc,Lond. 1881; p.200,,pl: xx xiv,, fig: 37. 
Grandidieria horei BourcuiGnat, Bull. Soc. Mal. Fr., II, 1885, 
pu:6: 
Nodularia horei Stimpson, Syn., 1900, p. 823. 
Smith believes that the shell from which his description 
and figure were made is young. It is quite thin and com- 
pressed and has an almost square subtruncation behind. 
NopULARIA BORELLIT (Ancey). 
Shell almost regularly obovate, greatly inflated; subsolid, 
somewhat inequilateral, beaks only slightly elevated; anterior 
end narrowed and rounded, slightly cut away below; base al- 
most evenly curved, but a little fuller behind the middle; out- 
line of dorsal slope rather full, almost squarely subtruncated 
behind ; anterior and posterior ends undulately rugose ; epider- 
mis dirty brown; hinge lightly arcuate; nacre brilliant, irides- 
cent. 
Length 29, height 19, diam. 16.5 mm. 
Lake Nyassa and vicinity. 
Umo borellu Ancry, Bull. Soc. Zool. Fr., VII, 1894, p. 226, 
fig. 2. 
Nodularia borellu Stmpson, Syn., 1900, p. 823. 
A small, inflated species with the umbones, the anterior and 
posterior ends of the shell corrugately wrinkled, dirty fuscous 
epidermis, and brilliant iridescent nacre. 
NODULARIA EMINI (von Martens). 
Shell subrhomboid, subinflated, subsolid, inequilateral ; beaks 
full and high, but not elongated; posterior ridge well devel- 
oped, rather narrowly rounded above, fading out somewhat 
below, ending near the base; hinge line slightly sinuous; ante- 
rior end angled above, rounded and cut away a little below; 
base line curved; dorsal slope obliquely truncate, the lower 
