﻿]5^ LAMI'SIMS 



Martiaron (Unio) cromtvellii Lisa, Syn., 1870, p. 49. 



Lampsilis cromwellii Simpson, Syn., 1900, p. 565. 



Vnio marginis Lf,a. Pr. Ac. N. Sci. Phila., IX, 1865, p. 89; Jl. 



Ac. N. Sci. Pliila.. \'\, 1869, p. 225. pi. xxxi, %. 69; Obs., 



XII, 1869, p. 15, pi. XXXI, fig. 69. 

 Margaron (Unio) marginis Lea, Syn., 1870, p. 49. 



A smoother, lighter colored shell than that of conmnculus, 

 and the nacre is not inirj)le. The beak sculpture consists of 

 .semicircular ridges, while those of conmnculus follow the 

 growth lines. This and Unio marginis seem to me to be abso- 

 lutely identical. 



Lampsius corvunculus (Lea). 



Shell elliptical or obovate, su'bcompressed or scarcely inflated, 

 rather thin to subsolid, with low beaks, which are sculptured 

 with a few singly-looped ridges, which nearly follow the growth 

 lines ; posterior ridge wanting ; surface with irregular growth 

 lines, and covered with a thick, brownish or blackish epidennis ; 

 left valve with two somewhat compressed ragged pseudocar- 

 dinals which arc partly joined above, and two low, curved lat- 

 erals; right valve with one pseudocardinal and a vestige of a 

 second above it, with one lateral having a groove along its 

 lower face ; beak cavities shallow ; posterior scars faint ; nacre 

 purple, iridescent and slightly thinner behind. The male shell 

 is somewhat rhomboid, but nearly evenly rounded behind ; that 

 of the female has a small, angular marsupial swelling not far 

 from the ])osterior end. and is obliquely truncated below the 

 elevated i^osterior point. 



Length 32, height 20, diam. 12 mm. 



Western Georgia ; Village Creek. Jefferson County, Ala- 

 bama : Lak'c Ashby, Florida. 



Type locality, Swam]) Oeek, Whitfield County, Georgia. 

 Unio con-unruius Lka. Pr. Ac. N. Sci. Phila., XII, 1868, p. 



144; Jl. Ac. N. Sci. Phila., VI, 1869, p. 314. pi. i.. fig. 127: 



Obs.. XII. i8r)(), p 74, pi. I., fig. 127. 



