UNIO 689 
UNIO LANCEOLATUS Lea. 
Shell elongated, subelliptical or subobovate, subcompressed 
or convex, inequilateral, subsolid; beaks not full or elevated, 
their sculpture not seen; posterior ridge full, narrowly round- 
ed, ending in a somewhat drawn-out point about on the median 
line; sometimes the point is turned up a little; surface with 
light incremental lines; epidermis straw-color, yellow or yel- 
lowish-green or brown, often showing the dark rest marks, 
shining ; pseudocardinals subcompressed, double in each valve, 
the upper one of the right valve small, laterals straight, one in 
the right valve and two in the left ; muscle scars small, shallow ; 
nacre bluish-white, flesh-color or salmon-tinted, thick in front. 
Length 58, height 25, diam. 15 mm. 
Length 62, height 25, diam. 13 mm. 
North Carolina; Virginia. 
Type locality, Tar River, Tarboro, N. C. 
Unio lanceolatus Lex, Tr. Am. Phil. Soc., 1828, p. 266, pl. 111, 
fig. 2: Obs., I. 1834, p. 8, pl. 10, fig. 2—Conrap, Monog., 
III, 1836, p. 32, pl. xtv, fig. 2—HAaANLey, Biv. Shells, 1843, 
p. 204, pl. xx, fig. 60; xx, fig. 26—CueEnu, Ill. Conch., 
1858, pl. vi, fig. 1, ta, 1b-—KustEeR, Conch. Cab. Unio, 
1861, p. 204, pl. Lxvut, fig. 4.—Sowerry, Conch. Icon., XVI, 
1866, pl. xi, fig. 236.—StMpson,. Syn., 1900, p. 734. 
Margarita (Unio) lanceolatus Lea, Syn., 1836, p. 35 
p. 24. 
Margaron (Unio) lanceolatus Lea, Syn., 1852, p. 
Pp. 57: 
Unio lanceolata Desuayes, Enc. Meth., IT, 1830, p. 585. 
A delicate, light-colored, polished species, which bears about 
the same relation to U. fisherianus and other members of the 
group that Lampsilis anodontoides and fallaciosa do to L. 
recta. Indeed it often closely imitates a voung delicate falla- 
ciosa, but is more elongated and compressed. 
UNIo viriputus Lea. 
Shell elongated, subelliptical, a very little wider behind than 
in front; inequilateral, scarcely subsolid, convex; beaks rather 
low, not inflated, their sculpture apparently strong, longitu- 
