144 CARDIAD^. 



of our shell is less smooth and polished than C. lavig-atnm, a differ- 

 ence which might depend on climate. Mr. Sanderson Smith states 

 that he sometimes finds shells in the Long Island bays without the 

 purple blotch. 



Cicnus APHRODITE, Lea. 1834. 



Shell sul)-cordiibrm, compressed, rather thin, beaks nearly cen- 

 tral, rather prominent ; valves smooth or slightly radiated, scarcely 

 gaping ; obsolete cardinal teeth. 



Aphrodite Groenlandica. 



Shell large, sub-triangular, drab-colored, with very numerous, obsolete radi- 

 ating ridges ; slightly gaping posteriorly, beaks slightly prominent, incurved ; 

 margin within salmon-colored, centre opaline. 



Cardium Graoiluudicuin, Chemn. Conch, vi. t. 19, fiij. 198. — Gmelin, Svst. 3:2.32, No. 22. 

 — Brug. Encyc. Moth. 222, No. 17, pi. 300, fig. 7. — Maton and Rackett, Lin. 

 Trans, viii. 69. — Dillwyn, Catal. i. 129. — La.m. An. sans Vert. vi. 407. — Wood, 

 Gen. Conch. 227; Index, pi. 5, fig-. 28. — Gould, Inv. 1st ed. 92. — Haxley, Re- 

 cent Shells, i. 134. — Migiiels, Shells of Maine, 15, and in Bost. Journ. iv. 321. — 

 De Kay, Nat. Hist. New York, 206, pi. 23, fig. 250. — Reeve, Conch. Icon. pi. 10, 

 fiff. 53. — Forbes and Hanl. Br. Moll. ii. 39. — Middend. Beitr. z. Malac. Koss. 

 iii. 41, ].l. 16, figs. 6-9. — Beck, in Gaimard Voy. en Island, Moll. pi. 15. 



Mactra radiata, Donovan, Brit. Shells, v. pi. 161. 



Cardium edentulum, MoNTACiu, Test. Br. Sup. 29. — Sowerby, Genera, fig. 2; Conchol. 

 Manual, fig. 123*. —Fleming, Brit. Anim. 425. 



Aphrodite cohunha, Lea, Trans. Am. Philos. Soc. (new series), v. pi. 18, fig. 54 (1834). 



Aphrodite Gruenlandica, Stimpson, Shells of New England, 19 (1851). 



Serripes Granlandicum, Chenu, Man. de Concli. ii. 109, figs. 496-498 (1862). 



Serripes Groenlandicus, Packard, Labrad. Mar. Anim. 23. 



Shell large, not very thick, sub-triangular, elevated, rather com- 

 pressed ; beaks not very prominent, curved inwards and slightly 

 forwards, nearly central ; anterior margin regularly rounded ; pos- 

 terior part somewhat elongated, margin protuberant beyond the 

 ligament, bordered by a slight wave, Avhich gives the posterior ter- 

 mination a somewhat sinuous or truncated appearance, and leaves 

 the shell gaping at this point ; this region is also more coarsely 

 wrinkled than the rest ; surface marked with minute lines of growth, 

 divided into zones by darker indications of the stages of growth, 

 which successive increments appear very loosely attached posteriorly ; 

 these are crossed l)y numerous inconspicuous, radiating ridges; 

 epidermis thin, shining, of a dral) or very liglit fawn-color ; hinge 

 slender ; cardinal teeth nearly wanting ; marginal teeth distinct. 



