﻿396 ANODONTA 



Kntire Mississippi drainage area; south Michigan; North 

 CaroHna to Georgia; southwest to Matamoras, Mexico. 



Type locahty, Wahash Kiver. 

 Anodonta imbccillis Sav, N. Marni. Diss., II, No. 23, 1829, p. 



355. — Ci.HSSiN, Conch. Cab. Ano., 1874, p. 70, pi. xix, figs. 



4, 5; XXV, fig. 4.— Haker, Moll. Chicago, Pt. i, 1898, p. 55, 



pi. V, fig. I. — Simpson, Syn., 1900, p. 635. 

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



p. 80. 

 Anodon imbecillis Sowkkhy, Conch. Icon.. X\ II, 1870, pi 



XXVII, fig. 102. 

 Anodonta incerta Lea, Tr. Am. Phil. Soc, \', 1834, p. 46, pL 



VI, fig. 16; Obs., I, 1834, p. 158, pi. VI, fig. 16. 

 Margarita (Anodonta) incerta Lea, Syn.. 1836, p. 51 ; 1838, 



p. 30. 

 Anodon incerta Catlow and Reeve, Conch. Nom., 1845, p. 67. 

 Anodon incertiis Sovveki'.y, Conch. Icon., X\'1I, 1867, pi. xvii, 



fig- 59- 

 Anodon horda Gould, Pr. Bost. Soc. N. H.. \\ 1855, p. 229. 

 Anodonta hordeum P.'ETel, Conch. Sam., Ill, 1890, p. 180. 



When perfect this is a beautiful, shining species, often of 

 a remarkably blue-green tint. In young or nearly adult shells 

 the beaks are compressed ; in old specimens they are often full 

 but flattCTied. In almost all specimens there is a decided gap 

 at the post-dorsal border and the dorsal slope. 



Anodonta henryana Lea. 



Shell olilong, nearly evenly elliptical. sul)infiated, thin, in- 

 equilateral, with compressed beaks, which have feeble, undulat- 

 ed sculpture ; dorsal and ventral lines parallel ; anterior end 

 rounded : posterior end w ith a blunt point at or belov^ the 

 median line: surface rather smooth; epidermis pale ashy or 

 yellow-green with two or three dark, wide, feeble rays on the 

 gaping posterior slope ; sometimes slightly banded ; nacre 

 bluish-while, sometimes with a ]nir]>lish tint. 



Length 72. height 40. diam. 25 mm. 



Northeast Mexico ; southern Texas. 



Type localitv. Matamoras and Tamaulipas. ^Icxico. 



