874 QUADRULA 
rest marks, rather cloth-like when fresh; pseudocardinals tri- 
angular, rough; laterals curved, that of the right valve usually 
single; muscle scars impressed ; beak cavities moderately deep ; 
nacre whitish, pinkish, purplish or red. 
Length 78, height 56, diam. 32 mm. 
Louisiana; eastern Texas; Mississippi; Alabama; north to 
Arkansas. . 
Type locality, New Orleans, La. 
Unio cerinus CONRAD, Monog., XI, 1838, p. 95, pl. L11.—Sow- 
ERBy, Conch. Icon., XVI, 1868, pl. Lxxxvi, fig. 468. 
Ouadrula cerina Simpson, Syn., 1900, p. 787. 
Fusconaja cerina OrRTMANN, Ann. Car. Mus., VIII, 1912, p. 
243. 
I have before me a shell from Lanana Creek, Nacogdoches 
County, Texas, which agrees well with Conrad’s figure of 
Unio cerinus. Other shells before me probably belong to the 
same species, but are not so typical. The waxen spots on the 
nacre, for which he bestowed the name cerinus, are present in 
the specimen before me from Texas and are probably patho- 
logic. In this shell they are bronzy-yellowish. 
QUADRULA HEBETATA (Conrad). 
Shell quadrate, rather inflated, solid, slightly inequilateral ; 
beaks moderately full and high; posterior ridge full, curved, 
angled throughout its length, ending in a point at the base of 
the shell; anterior end rounded; base line nearly or quite 
straight ; posterior end truncated, the upper part overhanging, 
the truncation slightly curved; surface rough, somewhat con- 
centrically sculptured; epidermis dull, shaggy, ashy-brown or 
blackish; pseudocardinals triangular, somewhat ragged; lat- 
eral in right valve somewhat double; muscle scars deep; beak 
cavities deep and compressed ; nacre white. 
Length 67, height 54, diam. 35 mm. 
Type locality, Missouri. Also, Tallapoosa River, Alabama. 
Unio hebetatus Conran, Jl. Ac. N. Sci. Phila., II, 1854, p. 2096, 
pl. xxv1, fig. 5. 
Margaron (Unio) habetatus Lea, Syn., 1870, p. 38. 
Ouadrula hebetata Simpson, Syn., 1900, p. 787. 
