UNIO 685 
and one in the right ; Jaterals very heavy, remote, double in the 
left valve and having a tendency to be double in the right; 
muscle scars small, deep, the anterior ones rough; beak cav- 
ities shallow ; nacre flesh-color or purplish, rather dull. 
Length 84, height 47, diam. 35 mm. 
Southern Georgia; north Florida. 
Type locality, Buck Lake, a bay of the Satilla River, Wayne 
‘Co. Ga: 
Unio downiei Lea, Pr. Ac. Nat. Sci. Phila., II, 1858, p. 166; 
Hie Ae Nat Sein Phila: AV; 1859;.p. 2r0, pl: xxv, fig. Or; 
Obs., VII, 1859, p. 28, pl. xxv, fig. 91—SowerrsBy, Conch., 
Icon., XVI, 1868, pl. Lxvint, fig. 350.—Simpson, Pr. U. 5S. 
Mats, Miss CV) 18092. p. 43; spl. av) figs. 1-3; LVL, figs 5); 
Sym, 1900; p17 33: 
Margaron (Unio) dowmet Lea, Syn., 1870, p. 41. 
A very solid, obovate, inflated, dull brown shell with strong 
teeth and deep scars. Its obovate form will distinguish it 
from the other members of the group. 
UnIo GEMINUS Lea. 
Shell slightly rhomboid or almost evenly long elliptical, in- 
flated, rather solid, inequilateral ; beaks moderately full but not 
high ; posterior ridge elevated, subangular or narrowly round- 
ed, inclined to be double below, ending behind at and below 
the median line in a slight biangulation ; surface with delicate, 
concentric ridges; epidermis dirty, tawny-greenish to nearly 
black with a few radiating rows of fine wrinkles, subshining 
on the disk; left valve with two moderate, stumpy, ragged 
pseudocardinals and two strong, curved laterals; right valve 
with one pseudocardinal and a vestigial one above it, with 
one solid lateral: beak cavities not deep; anterior muscle scars 
impressed ; posterior scars elliptical, shallow ; nacre lurid pur- 
plish, iridescent behind. 
Length 76, height 44, diam. 29 mm. 
Georgia. 
Type locality, Buckhead Creek, Burke Co., Ga. 
