﻿374 .\N()iH).\r.\ 



the liiiige line ; i>ost-(l()rsal wiiij^" scarcely developed ; surface 

 with low. irrei»"ular, concentric ridfji'es ; epidermis olive-green, 

 with lighter bands on young shells, dark green or blackish on 

 old ones ; nacre dull bluish or lead-color. 



Length 140, height 80, diam. 50 mm. 



Length 155, iieight 75, diam. 52 mm. 



Kamchatka ; Alaska. 

 Anodonta ccUcnsis ScnoTicK var. bcriui^iana AliuuiiNDoui-'K, 



Sib. Reise, 11, 1851, p. 284, pi. xwiii, figs. 4-7; xxix, figs. 



1-4. — Ci.ivSSiN, Conch. Cab. Ano., 1875. p. 211. pi. i^xv, figs. 



I, 2. 

 Anodonta \ouconensis Lka, IV. Ac. \at. Sci. IMiila., XI, 1867, 



p. 81. 

 Anodonta yonkanensis LiC.v, Jl. Ac. Xat. Sci. Phila., \'l, 1868, 



p. 287, pi. XI., fig. fx); Obs.. XII, 1869, p. 47. pi. XL, fig. 99. 



— Ci.KSSix, Conch. Cab. Ano., 1874, p. 133, ])1. xi.in, figs. 



1 , 2. 

 Mai'i^aro)! ( .hiodonta) yonkanensis Lka, S_\n., 1870, p. 80. 

 Anodonta youcancnsis Wv.'i'EL, Conch. Sam., Ill, 1890, p. 186. 

 .Inodonta beringiana Simpson, Syn., 1900, p. 628. 

 Anodonta cypica beringiana H.\xnihai.. Proc. Mai. Soc. Lon- 

 don, X, 1912, p. 125, pi. V, figs. 5-6. 



A large, rather iiiHated, dark colored, somewhat rough spe- 

 cies with dull colored nacre. It seems to be most nearly re- 

 lated to A. cygnca but is darker colored within and without; 

 the post-dorsal wing is less developed and the dorsal slope is 

 hardly ever truncated. Dr. W'm. II. Hall collected shells at 

 Petro])auIovsk, Kamchatka, that I consider identical with the 

 Alaskan form. 



AxoDoxTA ki:xxi:ri.vi Lea. 



Shell very thin, much elongated, generally elliptical, scarcely 

 intlated, very inequilateral, the low rather t1at beaks being 

 placed near the anterior end. their sculpture not seen ; posterior 

 ridge low an<l rounded; dorsal wing but slightly developed, an- 

 terior end sometimes a little truncated ; surface dull and con- 

 centrically striated behind, rather rough ; epidermis greenish- 



