CARUIUM. 141 



fringe upon the ribs, instead of little tubercles, marks it. It closely 

 resembles C. exig-uiim. also ; but, among other obvious differences, 

 that shell has an anu'ulated ibrni. 



Cardium elegantukim. 



Shell elongated oval, inequipartite, with twenty-six to twenty-eight rihs sep- 

 arated hy (lee[), wide grooves and eovered by arched bars. 



Cardinni degantuhun. Beck, in Morcii, Prod. Faun. Gni'nl. 20 (1857). 



Shell ^'ery small, elongated, ovate, rather compressed, anterior 

 end rather sharply rounded, posterior end slightly trun- 

 cated obliquely, posterior dorsal margin straight, a little ^'°' *^^- 

 sloping ; beaks at the anterior third, acute, moderately 

 elevated, inclined forwards, without a defined lunule in 

 front ; ribs twenty-six or twenty-eight, very strongly ^i,fiZT' 

 marked, the interspaces very deep and nearly as wide as 

 the ribs, which are uniformly covered with closel}^ imbricated arched 

 bars extending quite across each ril) ; the two posterior ribs much 

 broader than the others. Length, one fourth of an inch ; height, 

 one fifth of an inch ; breadtli, one eighth of an inch. 



Inhal)its Greenland. 



Easily distinguished from tlie last by its elongated form, smaller 

 size, and ribs in high relief, covered with transverse bars. 



Cardium pinnulatum. 



Fig. .57. 



Shell' small, sub-orbicuhu', with a slight angle posteriorly, snb-equipartite; sur- 

 face with twenty-six ribs, with a single i-ange of arched scales upon each. 



Cardium pinmdatum, Conrad, Joiun. Acad. Xat. Sc. vi. 260, pi. 11, fig. 8 (1831). — De 

 Kay, Nat. Hist. New York, 20.3, pi. 22, fig. 249. — Mighels, Shells of Maine, 16 ; 

 Bost. Journ. Nat. Hist. iv. .321. — S. Smith, Shells of Loult Island, Ann. New York 

 Lye. vii. 



Shell very small, fragile, dingy white, nearly orlucular, somewhat 

 ol)long ; nearly equipartite ; Jieaks slightly elevated, inclined in- 

 wards ; an obtuse not very obvious ridge passes from the l)caks to 

 the posterior point of the shell, rendering this side a little angular ; 

 the anterior area is shortest and regularly rounded ; surface with 

 about twenty-six slightly rounded ribs separated by a deej) linear 

 groove, on each of which is a series of equidistant, arched scales. 



