QUADRULA 899 
QUADRULA GLOBATA (Lea). 
Shell suborbicular or subelliptical, very much inflated, solid, 
inequilateral; beaks very full, high, apparently turned inward 
and forward over a lunule; anterior end rounded or slightly 
truncated ; outline of base and dorsal slope as well as the pos- 
terior part of the shell rounded; posterior ridge but slightly 
marked, curved; greatest diameter below the beaks, surface 
with rude, irregular growth lines; epidermis dull, greenish- 
brown or ashy-brown, often cloth-like, with broken, green rays 
in the young shell; pseudocardinals triangular, ragged; lateral 
of right valve double; beak cavities deep, compressed ; muscle 
scars small, deep; nacre bluish-white, thinner and slightly iri- 
-descent behind. 
Length 52, height 44, diam. 35 mm. 
Holston and ‘Tennessee Rivers, Tennessee; Etowah River, 
Georgia. 
Type locality, Holston River, Tenn.; Etowah River, Ga. 
Umo globatus Lea, Pr. Ac. N. Sci. Phila., I, 1871, p. 191; Jl. 
Rew Sere ita. Ville hors. p 5. ply t fios Tr Obs.) DTT, 
1974,(p- 9, pl. 1 Hg... 
Ouadruia globata SIMPSON, Syn., 1900, p. 793. 
While this form is nearly allied to OQ. subrotunda, I believe 
it to be a valid species. In all the specimens I have seen the 
beaks are badly eroded and the outline of the shell is either 
nearly orbicular or irregularly short elliptical. The posterior 
ridge is scarcely developed, the disks being almost evenly 
swollen from the anterior to the posterior ends. The hinder 
end of the shell is nearly evenly rounded, and in all these 
characters it differs from subrotunda, pilaris or any of the 
allied forms. The name globata is very appropriate. 
Group of O. glandacea. 
Shell rhomboid-oval, nearly straight below and slightly bi- 
angulate behind, with a well-defined double posterior ridge; 
beaks probably full; surface slightly and irregularly sulcate; 
epidermis wrinkled, tawny; hinge strong, the plate somewhat 
