﻿I.AMPSILIS 



105 



LaMPSIIJS VANUXEMENSIS (Lea). 



Shell elliptical or irregularly obovate, rather solid, somewhat 

 inflated, with a scarcely developed posterior ridge ; beaks rath- 

 er low, their sculpture a few ridges looped up in the middle; 

 surface with irreg-ular, concentric growth lines, which are often 

 somewhat sulcate, dull colored, not shining, varying from dirty 

 tawny throug-h oJive to nearly black ; there are two rather 

 stumpy pseudocardinals in the left valve and one and a vestige 

 of another in the right; two curved laterals in the left valve 

 and one in the rig'ht ; muscle scars shallow, the posterior ones 

 round ; nacre var}'ing from dirty purplish- white through sal- 

 mon-tinted to dark purple, often darker in the cavity of the 

 shell, sligfhtly thicker in front, not bright. Male shell long 

 elliptical, rather full at the posterior base and moderately sharp 

 pointed behind about midway up the height of the shell. The 

 female shells have a large, prominent marsupial swelling at the 

 extreme posterior base and the shell is truncated from this to 

 the posterior point, which is situated two-thirds of the way 

 up from the base. All the female shells I have seen are smaller 

 than those of the males. 



Length (male) 58, height 2>^, diam. 2t, mm. 

 Length (female) 41, heig'ht 2y, diam. 20 mm. 

 Cumberland and Tennessee River systems; headwaters of 

 the Coosa. 



Type locality, Cumberland River, Tenn. 

 Unio vanu.remcnsis Lea, Tr. Am. I'hil. Soc, VL 1838, p. 36, 

 pi. XI, fig. 31 ; Obs., IL 1838, p. 36, p]. XI, fig. 31.— Hanley! 

 Biv. Shells, 1843, p. 193, pi. xxii, fig. 56.— Chenu, 111. 

 Conch., 1858, pi. XIX, figs. 3, 3a, 3^. — KusTER, Conch. Cab. 

 Unio, 1862, p. 272, pi. xci, fig. 6. 

 Margarita (Unio) 7'anuxemensis Lea. Syn., 1836, p. 26; 1838, 



p. 19. 

 Margaron (Unio) vanuxemensis Lea, Syn., 1852, p. 29. 

 l.ampsilis z'annxemensis Simpson, Syn., 1900, p. 549. 

 Enrynia (Micromya) I'anuxemcnsis Ortmann, Ann. Car. 



Mus., VIIT, 1912, p. 342. 

 Margaron (Unio) I'anuxemii Lea, Syn., 1870, p. 46. 

 Unio Tonuxemii ?>. H. Wright, Check List, 1888. 



