784 PT,EUROBEMA 
Pleurobema reclusa Stmpson, Pr. Ac. N. Sci. Phila., 1900, p 
82, pl. 1, fig. 2; Syn., 1900, p. 760. 
Close to bilbosum. It is not so inflated as that species, its 
beaks are not so full, the dorsal slope is more plicate, the epi- 
dermis is greener, and the nacre is different. 
Group of Pleurobema brumbyanum. 
Shell oval, inflated, moderately solid, faintly swollen at post- 
basal region; beaks rather prominent, somewhat distant from 
the anterior end; beak sculpture not seen; disks irregularly, 
concentrically sculptured; epidermis dark olive to blackish, 
striate; pseudocardinals subradiate, slightly compressed; lat- 
eral of the right valve nearly or quite single; beak cavities 
shallow; nacre iridescent posteriorly, somewhat thickened in 
front. 
PLEUROBEMA BRUMBYANUM (Lea). 
Shell almost evenly elliptical, subinflated to inflated, sub- 
solid, inequilateral ; beaks somewhat elevated and inflated ; pos- 
terior ridge well developed, narrowly rounded or subangular, 
ending behind in a blunt point at the median line ; anterior end 
rounded ; base line curved, sometimes a little fuller just behind 
the middle: outline of dorsal slope curved, elevated at the 
hinder end of the ligament almost into an angle; surface un- 
evenly -and somewhat feebly concentrically sculptured, the 
sculpture strongest on the dorsal slope; epidermis greenish- 
brown to blackish, rather smooth, subshining ; pseudocardinals 
slightly subcompressed, two in the left valve and one in the 
right; two delicate laterals in the left valve and one in the 
right; muscle scars rather shallow; beak cavities not deep; 
nacre whitish, a little thicker in front. 
Length 52, height 34, diam. 22 mm. 
Length 47, height 30, diam. 22 mm. 
Alabama River system. 
Type locality, Warrior River, Tuscaloosa, Ala. 
Unio brumleyanus Lea, Proc. Am. Phil. Soc., II, 1841, p. 82. 
Unio brumbyanus Lea, Tr. Am. Phil Soc., VIII, 1842, p. 245, 
pl. xxvi, fig.c62;Obs., ITT, 1842) p--8a; pla xxv, fies Gat 
