﻿ANt)DONTA 391 



I know nothing- whatever of this shell beyond the tigure 

 and meagre description given by its author. He gives no 

 account of the color of the nacre or epidermis, but the figure 

 shows the latter to be yellowish-ashy. It seems to differ from 

 anything I know, but may possibly be a young ./. hallcnbeckii. 



Anodonta iMPi^iCATA Say. 



vShell oblong, elliptical, often solid, subrhomboid or ovate 

 in outline, subinflated, inec|uilateral with moderately full beaks, 

 which rise a little above the dorsal outline, their sculpture 

 consisting of straight bars running parallel with the hinge 

 line, or they may be slightly curved and sometimes a little 

 corrugated ; posterior ridge well developed, generally more or 

 less double, and ending in a biangulation a little below the 

 median line ; surface with irregular growth lines, which 

 sometimes rise into ridges ; epidermis yellowish-green, olive 

 or brown, occasionally faintly rayed, scarcely shining, often 

 rough ; nacre whitish, dull salmon or purplish, almost always 

 darker in the cavity of the shell, and thickened in front. 



Length 125, height 67, diam. 45 mm. 



Length 142, height 83, diam. 50 mm. 



St. Lawrence drainage ; north to Lake Winnipeg ; south in 

 streams flowing into the Atlantic to Virginia ; not reported 

 from Michigan. 



Type locality, Danvers. Mass. 

 Anodonta implicata Sav, New Harm. Diss., II, No. 22, 1829, 



p. 340. — Cr^ESSiN, Conch. Cab. x\no., 1873, P- 7^, pk xix, 



fig. 3. — Simpson, Syn., 1900, p. 633. 

 Anodon implicata Goui.d, Inv. Mass., 1841, p. 118, fig. 78; 2d 



ed., 1870. p. 180, fig. 481. — Hartman and Michener, 



Conch. Cest., 1874, p. 94. fig. 193. 

 Margaron (Anodonta) iniMlcafa hE.\. Syn., 1852, p. 50; 1870, 



p. 80. 

 f Anodon implicatiis Sovvi;rt!Y, Conch. Icon., N\"n. 1867. pi. 



XIII, fig. 44. 

 Anodonta newtonensis Lea. Tr. Am. Phil. Soc. VL 18^8. ]). 



79, pi. XXI, fig. 66; Obs., H. 1838, p. 79, pi. xxi, fig. 66. 

 Jfari^anta (Anodonta) nezctonensis Lea, Syn.. 1838, p. 30. 



