﻿132 I.AMPSII.IS 



Lampsilis trabalis (Conrad). 



Shell solid, inflated, quite inequilateral, irregularly oval, with 

 full, rather high beaks, which are turned forward and sculp- 

 tured with a few coarse, doubly-looped ridges ; lunule small, 

 passing backward and filled with epidermal matter ; posterior 

 ridge somewhat full, rounded ; surface with irregular growth 

 lines, dirty olive-green, with numerous faint, wavy rays ; left 

 valve with two solid, triangular pseudocardinals and two long, 

 straight, club-shaped laterals, the groove between them extend- 

 ing to the epidermal matter of the hinge ; right valve with three 

 pseudocardinals. the central one solid and triangular, the oth- 

 ers small, and one lateral with a vestige of a second below it; 

 beak cavities shallow, Showing a few dorsal scars ; muscle scars 

 deep ; nacre white or bluish-white with bluish or greenish iri- 

 descence behind, much thicker in front. The male and female 

 shells dififer remarkably, the former being narrowed about at 

 the center and drawn out behind into a sort of beak. This 

 elongation is obliquely truncated above behind and ends in a 

 rounded point below, the base line being generally a little in- 

 curved ; the female shell is higher, more nearly evenly ovate, 

 slightly truncate behind above, and has the base line rather 

 evenly curved. 



Length hnale) 50, height 27, diam. 19 mm. 



Length (female) 54, height 35, diam. 25 mm. 



Kentucky and streams of Tennessee ; Clinch River, Virginia. 



Type locality, not given. 

 Unio trabalis Conrad, New F. W. Shells, May 3, 1834, p. 27, 



pi. HI, fig. 5 ; p. 72 ; Monog., XH, 1840, p. no, pi. LX, fig. 2, 



— Chknu, Bib. Conch., ist sen, IH, 1845, p. 15, pi. 11, fig. 3. 

 Lampsilis trabalis Simpson, Syn., 1900, p. 558. 

 Biirynia (Micromya) trabalis Outmann, Ann. Car. Mus.. 



VTIT. 1912, p. 340. 

 Unto troostensis I<ka, Tr. Am. Phil. Soc, V, 1834 (August or 



September), p. 71, pi. x, fig. 30; Obs.. L 1834. p. 183, pi. 



X, fig. 30. — Hanley, Biv. Shells, 1843, p. t86, pi. xxiii, fig. 



24. — KusTER, Conch. Cab. Unio, 1861, p. 193, pi. lxt, fig. 4. 



— SowERP.Y, Conch. Icon., XVL 1868, pi. Lxxviii, fig. 406. 



