﻿LAMPSILIS 



^59 



Mar gar on fUnio) connmcidus Lea, Syn., 1870, p. 49. 

 L.ampsilis corvunculus Simpson. Syn., 1900, p. 566. 



Thinner, shorter and more compressed than L. paiila, and it 

 has a piirj^le instead of a whitish nacre. The female does not 

 have the small radial ridgre that is found on that of paula. 



IvAMPSiLis PAutA (Lea). 



Shell long elliptical, rather solid, inflated ; beaks full but not 

 high, sculptured, with a few singly-looped ridges, which are 

 curved up quite sharply behind ; surface covered with irregular 

 growth lines, which sometimes form strong concentric ridges ; 

 in the young shells the epidermis is often green with one or 

 two light rays on the posterior slope and with concentric yel- 

 lowish bands ; in the adult shells it is thick and black ; left valve 

 with two low, irregular, ragged pseudocardinals, which are 

 often partly joined together and are sometimes slightly reflexed, 

 and two laterals; right valve with one pseudocardinal, some-, 

 times with a vestige of a second, and one lateral ; beak cavities 

 shallow ; muscle scars well marked ; nacre dirty white or lurid, 

 iridescent behind. Male shell nearly evenly long elliptical, 

 rounded before and behind, slightly thicker in front; female 

 shell irregularly long elliptical ; the posterior base but slightly 

 swollen, angular, and there is often a small radiating ridge 

 leading from the beaks to this part of the shell ; behind this it 

 is obliquely truncate to the posterior point, which is more than 

 midway up from the base ; the hinder part of the shell is much 

 thinner than the front part. 



Length (male) 2,7, height 22, diam. 16 mm. 

 Length (female) 36, height 21, diam. 20 mm. 

 Flint and Chattahoochee Rivers, Georgia. 

 Type locality, Chattahoochee River, Columbus, Ga. 

 Unio pauhis Lea, Pr. Am. Phil. Soc, I, 1840, p. 287 ; Tr. Am. 

 Phil. Soc, VIII, 1842, p. 213, pi. XV, fig. 29; Obs., Ill, 1842, 

 p. 51, pi. XV, fig. 29. — Chenu, 111. Conch., 1858, pi. xxvii, 

 figs. 5, 5a, 5^7. — KusTER, Conch. Cab. Unio, 1861, p. 260, pi. 

 LXXXVIT, fig. 6. 

 Margaron (Unio) pauhis Lea, Syn., 1852, p. 31 ; 1870, p. 49. 



