UNIO 659 
cloth-like. Sometimes slightly produced behind the center of 
the base. 
Length 98, height 50, diam. 21 mm. 
Length 95, height 45, diam. 20 mm. 
North Carolina and northward. 
Type locality, Roanoke River, between Winton and Tarboro, 
Ne C22 Camden? 1S. C. 
Unio jejyunus Lea, Tr. Am. Phil. Soc., VI, 1838, p. 9, pl. 1v, 
fig. 9; Obs., II, 1838, p. 9, pl. iv, fig. 9 —HANteEy, Biv. Shells, 
1843, p. 199, pl. xx, fig. 47,—Kustrr, Conch. Cab. Unio, 
1862, p. 265, pl. xc, fig. 1.—?Sowerby, Conch. Icon., XVI, 
T868, pl. Lxviu, fig. 347. 
Margarita (Unio) jejunus 1A, Syn., 1836, p. 30; 1838, p. 22. 
Maregaron (Unio) jejunus Lea, Syn., 1852, p. 32; 1870, p. 51. 
Unio complanatus var. jejunus SIMPSON, Syn., 1900, p. 725. 
Unio percoarctatus Lea, Pr. Ac. N. Sci. Phila., I, 1857, p. 85; 
esc aN ocieniar, Vij tSO2) po Soa pl, iin, fe. 200; Obs., 
VIII, 1862, p. 63, pl. 1, fig. 206.—Sowersy, Conch. Icon., 
DOV 1866, ple civ, fie. 277. 
Margaron (Unio) percoarctatus Lea, Syn., 1870, p. 51. 
Var. quadrilaterus Lea. 
Shell decidedly rhomboid; posterior ridge distinctly double, 
ending in a well-marked biangulation at the posterior base; 
base line generally incurved in old shells. Nacre whitish, 
lurid purplish or purple. 
Length 71, height 41, diam. 23 mm. 
Length 55, height 33, diam. 23 mm. 
South and North Carolina; Florida. ? 
Type locality, Abbeville District, S. C.; Neuse River, Ral- 
eigh, N. C. 
Unio squalidus Lea, in part, Pr. Ac. N. Sci. Phila., VII, 1863, 
p. 192; Jl.. Ac. N. Sci. Phila. VI, 1866, p. 22; Obs., <a 
1867, p. 26.—Stmpson, Pr. U. S. Nat. Mus., XV, 1892, P. 
429, pl. LXxtI, fig. 14. 
Margaron (Unio) squalidus Lea, Syn., 1870, p. 51. 
