642 UNIO 
one lateral; beak cavities shallow; muscle scars impressed; 
nacre purplish. salmon or fesh-color, generally bright. 
Length 66, height 38, diam. 22 mm. 
Length 67, height 40, diam. 24 mm. 
South Carolina to Florida. 
Type locality, Buckhead Creek, Burke Co., Ga. 
Unio obnubtlus Lea, Pr. Ac. N. Sci. Phila., [X, 1857, p. 169; 
Jip AcuN- Say Phila:, 1V) 1858p. S4, pk xviny ie.64-*Obss 
VI, 1858, p. 84, pk xvi, fig. 64.—Simpson, Pr. U: S. Nat. 
Mus., XV, 1802; p.’ 424, pl. TxviG fies 35 Syl clOOo, pa 710: 
Margaron (Unio) obnubilus La, Syn., 1870, p. 53. 
Uimo opacus Lua, Pr. Ac. N. Sc. Phila, VX; 1857; p; 169; |i 
ANe.N. Sci. Phila. IV, 1858, pa xvi ic.66; Obs, VWailerees: 
p--86, pl xvii; he. 66. 
Margaron (Unio) opacus Lea, Syn., 1870, p. 52. 
Unio equatus Lea, Pr. Ac. N. Sci. Phila., IX, 1857, p. 170; 
ji. Ac: N.-Seu Phila 1858, p: 80, pl* xix hie. Gos Obs: Va. 
1858, p. 80, Pl-x1x, fies 60: 
Margaron (Unio) equatus Les, Syn., 1870, p. 52. 
Unto viridicatus Lea, Pr. Ac. N. Sci. Phila., 1X, 1857, p. 170; 
JisAc. N.Set. Phila., TV, 1858, p: 87; pk xvi he: 67 Obs: 
VI, 1858;'p187 pl xviig shes 67: 
Margaron (Umo) viridicatus LEA, Syn., 1870, p. 52. 
Unio hepaticus Lea, Pr. Ac. N. Sci. Phila., III, 1859, p. 154; 
Jl AceN: Se. *Pinla.. TV 51860, pu-346e pl aLuin phoasie 
Obes V Mik pe Bos pls Evite ae 
Margaron (Unio) hepaticus Lea, Syn., 1870, p. 52. 
Unio santeénsis LEA, Pr. Ac. N. Sci. Phila., I, 1871, p. 193.—J}. 
Ac..N Sci >Phila,, Vill e1874)p) 20; pl vi, shige Ones 
XIN, 1874, p:924. pl. vig tig. 17: 
Unio nolan BeoHi> Wricht, Pr Ac. Ne Sem Bila. s16se.p 
L103) pls nV, fig. 
This is a sort of exaggerated U. occultus. It is generally 
more rhomboid, larger and heavier than that species and has 
a more northerly range. Occasional specimens are somewhat 
produced in the post-basal region. 
