﻿88 LAMPSILIS ♦ 



Lampsii,is perdix (Lea). 



Shell larg'e, long elliptical, moderately solid, subinflated, with 

 a well-developed posterior ridg^c ; beaks rather full, their sculp- 

 ture not observed : surface with irregular growth lines, decid- 

 edly concentrically ridged in front, nearly smooth at the mid- 

 dle of the shell, roughened on the posterior slope, dirty yellow- 

 ish-green or tawny, generally marked with faint, wide, broken 

 rays ; left valve with two equal-sized, erect pseudocardinals 

 and two remote, small, .short laterals; right valve with one 

 verv high pseudocardinal, a smaller one in front and some- 

 times a vestigial one behind it and one rather high, 

 short lateral : muscle scars very large, well impressed ; 

 beak cavities rather deep ; nacre bluish-white to creamy, 

 silvery, with a wide prismatic border, thickened in front. The 

 male shell does not differ greatly from that of the female, the 

 latter being a little more rounded behind, and having a slight, 

 wide marsupial swelling. Both male and female shells gape 

 slightly at the anterior base. 



Length 155, height 100, diam. 60 mm. 



Tennessee and Cumberland River systems. 



Type locality. Harpeth River, Tenn. 

 Unio perdix Lea, Tr. Am. Phil. Soc, V, 1827, p. 72, pi. xr, fig. 



31 ; Obs., L 1834, p. 184, pi. XT, fig. 31. — HanIvEY, Biv. Shells, 



1843, p. 188. pi. XX, fig. 20. — SowERBY, Conch. Icon.. XVL 



1868, pi. LXIX. f^g. 82. 

 Margarita (Unio) perdix Lea. Syn., 1836, p. 23; 1838, p. 18. 

 Margaron (Unio) perdix Lea, Syn., 1852, p. 26; 1870, p. 41. 

 Lampsilis perdix Simpson, Syn., 1900, p. 542. 

 Nephronajas perdix Oktmann, Ann. Car. Mus.. VIIL 1912, 



p. 326. 

 Unio pectorosiis Conrad, New F. W. Shells, 1834, p. 37, pi. 



VI, fig. I, p. 71 ; Monog., IIL 1836, p. 25, pi. xi, fig. i. — 



Hanixy, Biv. Shells, 1843, P- 189, pi. xxi, fig. 22.— Chenu. 



Bib. Conch., ist ser.. IH, 1845, P- ^9' P^- ''• ^"- ^- — Kuster, 



Conch. Ca'b. Unio, 1852, p. 26, pi. iv. fig. 2. 

 Margarita (Unio) pectorosus Lea, Syn.. 1836, p. 23; 1838, p. 



18. 



