﻿ANODONTA 429 



Anodonta opaca Lea, Tr. Am. Phil. Soc, X, 1852, p. 285, pi. 

 XXV, fig. 46; Obs., Y, 1852, p. 41, pi. XXV, fig. 46. — Clessin, 

 Conch. Cab. Ano., 1875, p. 209, pi. lxiv, figs, i, 2. — Simp- 

 son, Syn., 1900, p. 645. 

 Margaron (Anodonta) opaca Lea, Syn., 1852, p. 50; 1870, p. 

 80. 



This may be merely a variety of A. grandis, but it has a 

 somewhat dififerent texture from any of the forms of that or 

 any other species I know of. It is generally dark and smoky 

 •externally, and the nacre has a soft, rich tint that is not often 

 found in the genus. The young shell is sometimes greenish 

 with dark, concentric bands. 



Anodonta stewartiana Lea. 



Shell irregularly ovate or subtrianguiar, somewhat inequi- 

 lateral, strong, with very high, full beaks, the umbonal swelling- 

 extending out on the disks; beak sculpture strongly corrugat- 

 ed, doubly looped and nodulous ; posterior wing low, often 

 rounded behind : dorsal slope subtruncate, the outline usually 

 a little incurved ; posterior ridge very faint, ending behind in 

 a blunt point at or a little above the median line ; upper part 

 of the anterior end generally angled : base line straight or 

 rounded; curved up decidedly behind ; surface with irregular 

 growth lines or sulcations, dull or subshining, dirty olive- 

 green to brown, often when fresh having a peculiar grayish 

 tint or bloom, which wears off when the shell is handled : 

 nacre whitish or reddish. 



Length 166, height 100, diam. 68. mm. 



Length 140, height 95, diam. 68 mm. 



Arkansas ; Louisiana ; Texas. 



Type locality. River Teche, La. 

 Anodonta stcioartiana Lea, Tr. Am. Phil. Soc, \', 1834, p. 47, 



pi. \i, fig. 17; Obs., L 1834, p. 159, pi. VI. fig. 17. — Cle-ssin. 



Conch. Cab. Ano., 1874, p. 150, pi. xlviii, figs. 3. 4. — Simp- 

 son. Syn., 1900, p. 645. 

 Margarita (Anodonta) stewartiana Lea, Syn., 1836, p. 52; 



1838, p. 31. 



