﻿112 I.AMl'SH.lS 



by the eniargination behind the swelling. The form found 

 in the Atlantic drainage has generally received the name given 

 by Conrad, while that found in the Temiessee system has been 

 called by Lea's name. A careful examination of a consider- 

 able series of shells from both regions convinces me that they 

 are identical. 



Lampsilis apicina (Lea). 



Shell small, subsolid, smooth, elliptical, rather compressed, 

 nearly equilateral, the posterior point less than half way up 

 from the base, slightly and obliquely truncate above this point ; 

 beaks rather full, regularly and beautifully sculptured with fine, 

 doubly-looped ridges ; ligament short ; epidermis yellowish- 

 brown, covered with small, nearly equidistant rays ; pseudo- 

 cardinals small, compressed, two in each valve ; laterals deli- 

 cate, nearly straight, two in the left valve and one in the right ; 

 anterior cicatrices distinct, posterior faint ; nacre bluish or 

 purplish. 



Length 30, height 18, diam. 9 mm. 



Type locality, Othcalooga Creek, Gordon County, Georgia. 

 Unio apiciniis Lea, Pr. Ac. N. Sci., Phila., IX, 1857, P- 3^ ; 



Jl. Ac. N. Sci. Phila., IV, 1858, p. 76, pi. xiv, fig. 56; Obs., 



VI, 1858, p. 76, pi. XVI, fig. 56. 

 Margaron (Unio) apicinus Lea, Syn., 1870, p. 44. 

 Lampsilis apicinus Simpson, Syn., 1900, p. 551. 



I have only seen a few specimens of this shell,- which is not 

 represented in the Lea collection, the type probably being lost. 

 The specimens I have examined are most likely males, and I 

 cannot be certain as to their relationship, but place the species 

 here provisionally. 



Lampsilis occidentalis (Conrad). 



Shell obovate or subrhomboidal, convex, thin or subsolid, 

 rounded in front, bluntly jx>inted or subbiangulate behind ; 

 posterior ridge scarcely developed ; beaks slightly elevated, 

 their sculpture not seen, but probably having fine, doubly-loop- 

 ed ridges; epidermis yellowish, yellowish-green or brownish, 

 with numerous more or less distinct rays, mostly on the hinder 



