CARDIUM. 141 



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

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

 that shell has an angulated form. 



Cardium elegantulum. 



Shell clong-ated oval, inequipartite, Avith twenty-six to twenty-eight ribs sep- 

 arated Ijy deep, wide grooves and covered liy arched Ijurs. 



Cardinm elef]antuJum, Beck, m Morcii, Prod. Faun. Gr.jcnl. 20 (1S57). 



Shell very small, elongated, ovate, rather compressed, anterior 

 end rather sharply rounded, posterior end slightly trun- 

 cated ol)liquely, posterior dorsal margin straight, a little ^'°- *^^' 

 sloping ; l)eaks at the anterior third, acute, moderately 

 elevated, inclined forwards, without a defined lunule in 

 front; ribs twenty-six or twenty-eight, very strongly 

 marked, the interspaces very deep and nearly as wide as 

 the ribs, which are uniformly covered with closely imbricated arched 

 bars extending quite across each rib ; the two posterior ribs much 

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

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



Inhabits Greenland. 



Easily distinguished from the last by its elongated form, smaller 

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



Cardium pinnulatum. 



Fio. 57. 



Shell small, sub-orbicular, Avith a slight angle posteriorly, sub-equipartite ; sur- 

 face Avith twenty-six ribs, Avitli a single range of arched scales upon each. 



Cardium piniiu/atnin, Coxkad, Journ. Acad. Nat. Sc. vi. 260, pi. 11, fig. 8 (18.31)— De 

 Kav, Nat. Hist. New York, 20.5, pi. 22, fig. 249. — Mighels, Shells of Maine, 16 ; 

 Bost. Journ. Nat. Hist. iv. 321. — 8. S.mitii, Shells of Long Island, Ann. New York 

 Lye. vii. 



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

 oblong ; nearly equipartite ; beaks slightly elevated, inclined in- 

 wards ; an obtuse not very obvious ridge passes from the beaks 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 deep linear 

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



