868 QUADRULA 
QUADRULA WRIGHTII Nn. s. 
Shell subrhomboid or subtriangular, convex to inflated, solid, 
inequilateral: beaks somewhat elevated, not inflated, their 
sculpture a few coarse, undulating ridges; posterior ridge full, 
narrowly rounded, ending near the base in a blunt point; an- 
terior end obliquely truncated above, rounded below; base 
line curved ; post-dorsal outline usually rounded from the beaks 
to the base, sometimes truncated behind; surface irregularly, 
concentrically sculptured ; epidermis dark reddish-brown, some- 
what silky; pseudocardinals considerably split up; lateral in 
right valve sometimes slightly double; beak cavities rather 
deep, compressed ; muscle scars small; nacre violet at the bor- 
der, lighter colored in the cavity of the shell. 
Length 55, height 44, diam. 25 mm. 
Length 43, height 37, diam. 25 mm. 
Type locality, Pine Barren Creek, Escambia County, Florida. 
1 formerly thought this was identical with Q. succissa, but 
although the specimens before me show much variation they 
differ from that species constantly in being solider, shorter and 
in the pattern of coloring of the nacre. Young shells are 
shorter and solider than Lea’s cacao. 
QUADRULA PUMILA (Lea). 
Shell small, subrhomboid, convex, scarcely subsolid, inequi- 
lateral; posterior ridge full, somewhat double below ; anterior 
end rounded, narrowed and slightly truncate above; base line 
nearly straight; posterior end obliquely subtruncated ; epider- 
mis reddish-brown, somewhat cloth-like; pseudocardinals tri- 
angular ; laterals straight ; beak cavities moderately deep ; mus- 
cle scars small; nacre dirty or lurid purplish. 
Length 28, height 19, diam. 13 mm. 
Type locality, Black river, North Carolina. 
Unio pumilus Lua, Tr. Am. Phil. Soc., VI, 1838, p. 23, pl. vir, 
fig. 17; Obs., II, 1838, p. 23, pl. vu, fig. 17—HAn ey, Biv. 
Shells, 1843, p. 185, pl. xxutr, fig. 13—-CueEnu, Ill. Conch., 
i858, pl. xrx, figs. 1, ra, 1b—Sowersy, Conch. Icon., XVI, 
1866, pl. xxxv1, fig. 198. 
