896 QUADRULA 
sulcate. Shell compressed at the base, slightly flattened on 
the sides, umbonal slope rounded, posterior slope rather wide, 
with a dark impressed line from beaks to basal margin. Beak 
sculpture unknown. Cardinal teeth heavy and solid, rather 
compressed, corrugate and sulcate; lateral teeth short, thick 
and slightly curved. Anterior cicatrices small and deep; pos- 
terior cicatrices distinct and well impressed; shell cavity wide; 
cavity of the beaks deep and obtusely angular; nacre white. 
Diam. 1.4, length 2.2, breadth 2.3 inches.”’ (Marsh). 
Type locality, Little Tennessee River, Tenn., and Holston 
River, Tenn. 
OQuadrula becuchampu Marsi, Naut., XVI, 1902, p. 7, pl. 1, 
lower two figures. 
“T obtained three specimens from Wm. M. Beauchamp a 
number of years ago; afterwards Mrs. Geo. Andrews sent me 
several of them from Holston River, Tenn. They are near 
globatus Lea, but were too different to place with that species. 
In outline they are subtriangular, not spherical and rounded 
like that species. ‘They are more solid and heavy and a larger 
species than globatus. ‘They have a lighter colored epidermis, 
with closer growth lines and the surface of the shell is rougher. 
They need not be confounded with my andrewsii as they differ 
in outline, teeth and character of the rays and are a very 
much larger species and more solid and heavy. ‘They vary 
greatly in character of the rays;.some are rayless, two have 
obscure maculations, while some have very obscure, indistinct 
rays.” 
QUADRULA CUNEUS (Conrad). 
Shell subovate, subinflated to inflated, more or less solid, 
inequilateral ; beaks high and quite full; diameter through the 
umbonai region greatest; disks flattened behind the middle 
and descending wedge-shaped to the posterior extremity; an- 
terior end rounded, sometimes slightly truncate above ; outline 
of base and dorsal slope curved; surface with irregular, con- 
centric growth lines; epidermis reddish-brown, more or less 
rough; teeth heavy; lateral of right valve disposed to be 
