636 UNIO 
xu 
Unio MICANS Lea. 
Shell subelliptical or subrhomboid, “convex, inequilateral, 
rather thin to subsolid; beak only moderately raised and full, 
their sculpture a few strong, subconcentric ridges, which are 
strongest where they cross the posterior ridge; posterior ridge 
full, narrowly rounded, ending behind in a blunt point below 
the median line; surface generally smooth; epidermis ashy- 
green or yellow-green, faintly rayed or rayless; left valve 
with two small, subcompressed pseudocardinals and two deli- 
cate laterals; right valve with one pseudocardinal and one 
lateral; baek cavities shallow; muscle scars not impressed; 
nacre bluish-white, rather dull. 
Length 50, height 26, diam. 17 mm. 
North Carolina to South Georgia and Florida. 
Type locality, Catawba River, Gaston Co., and Deep River, 
Gilt INC: 
Unio micans Lea, Pr. Ac. N. Sci. Phila., I, 1857, p. 85; Jl. Ac. 
N. Sci) Phila; V; 1862;. p50, pl-1m, fie. 2075;-Obs.. Vine 
1862, p. 63, pl. m1, fig. 207—Sowrrpy, Conch. Icon., XVI, 
1866, pl. xxxv, fig. 182-——Srmpson, Pr. U. S. Nat. Mus., 
XV, 1892, Dp. 423, pl. Lxv, fig. 3;—-Syn., 1900, p. 714. 
Margaron (Unio) micans Lea, Syn., 1870, p. 45. 
Unio perlucens Lea, Pr. Ac. N. Sci. Phila., VII, 1863, p. 193; 
jlo Ae. No Sei: Phila, VE 11866; pa 18, plies tie 210. Obs 
Xe, 1867,p. 220 pl. vse: 16: 
Margaron (Unio) perlucens Lea, Syn., 1870, p. 45. 
Close to cumninghanu but thinner, less rhomboid, and with 
a lower posterior ridge. 
Unio LEHMAN S$. H. Wright. 
Shell short elliptical, solid, convex, inequilateral ; beaks only 
moderately full or high, their sculpture not seen; posterior 
ridge full, faintly double, ending behind in rather narrow 
biangulation just below the median line; surface nearly smooth, 
yellowish-green to olive or brownish, faintly rayed, shining : 
left valve with two heavy pseudocardinals and two laterals; 
