﻿3yO ANOIMDNTA 



? Auodoii subcyiindiacca Sovvkkuy, Conch. Icon, XVll, 1807, 



pi. XV, tig'. 47a. 

 .liiodoii cxilis Sow i:ki:v, Concli. Icon., X\ II, uS^jy, pi. xxii, 



tig. 84. 

 f Anodoti pludadifoniiis Sowkki'.v, Conch. Icon., X\ll, 1870, 



pi. XXVI 1, fig'. 106. 



This i.s ahnost invariably a thin shell, yet 1 have seen a 

 few specimens slightly thickened in front. Ordinarily even 

 in old shells the external sculpture shows quite distinctly on the 

 inside. The nacre of this species is ditiferent usually from thai 

 of any other Xorth American form, having a tint a little like 

 dull silver. The larger dimensions given are for unusually 

 well-developed specimens, the ordinary manifestation being 

 about 85 to (p millimeters in length. 



I am very sure that this = the .1. fragilis Lamarck, and not 

 the Hwi-iatilis Dillwyn, as Dr. Lea believes. Say describes it 

 as very thin and fragile : epidermis green-olive, ])aler on the 

 disk and greener before (behind), within bluish-white, edged 

 with whitish, and from his dimensions and figure it is a smaller 

 shell than Dillwyn's, the whole agreeing better with the fra- 

 gilis of Lamarck. 



Anodonta ti;uks Conrad. 



Shell somewhat elongated, subrhomboid, wider behind, in- 

 flated, inequilateral, with a low post-dorsal wing, which is 

 rounded behind : posterior ridge moderate, double, ending 

 behind in a wide biangulation a little below the median line; 

 the dorsal slope obliquely truncated ; beaks moderately full, 

 raised somewhat above the dorsal line", their sculpture not 

 known ; epidermis ashy, tinted yellowish. 



Conrad states that the shell attains a length of four or more 

 inches. His figure is 75 millimeters long and 38 in height. 



Tvpe locality, Santee Canal, South Carolina. 

 Anodonta teres Co.nuad, Xew F. W. Shells. 1834. p. 47. pi. vii, 



fig-. 2.— CiiENU, P.ib. Conch., ist ser., TTT. 1845. P- -5- P^- "- 



fig. Q. — Simpson. Syn., 1000. p. 633. 



