144 CARDlADJi:. 



of our shell is less smooth and polished tliaii C. IcEvigatnm, 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. 



Goniis APHRODITE, Lea. 1834. 



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

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

 gaping ; obsolete cardinal teeth. 



Aplirodite GroBnlandica. 



Shell large, sub-triaugular, drab-coloreil, Avitli very numerous, obsolete radi- 

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

 margin within salmon-colored, centre opaline. 



Cardium (Iraidundicum, Cuemn. Com-li. vi. t. 19, lig. 198. — Gmelin, Syst. Zi'i'l, No. 22. 

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

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

 Gen. Conch. 227; Index, j)l. 5, fii;. 28. — Goild, Inv. 1st cd. 92. — Hanley, Re- 

 cent Shells, i. l.'U. — MiGHELS, Shells of Maine, 15, and in Bost. Journ. iv. .321. — 

 De Kay, Nat. Hist. New York, 200, ]il. 2:3, fi^-. 250. — Reeve, Conch. Icon. pi. 10, 

 fig. 53. — Fonr.ES and II.\nl. Br. Moll. ii. 39. — Middexd. Beitr. z. Malac. Ross. 

 ill. 41, pi. 16, fips. 6-9. — Beck, in Gainiard Voy. en Island, Moll. pi. 15. 



Mactra radiatu, Donov.vn, Brit. Sliells, v. jil. 161. 



Cardium edentnhim, Montagu, Test. B)-. Sup. 29. — Soweeby, Genera, fig. 2; Conchol. 

 Manual, fig. 123*. — Flemixg, Brit. Anini. 425. 



Aphrodite columha. Lea, Trans. Am. Philos. Soc. (new series), v. |)1. 18, fig. 54 (1834). 



Aphrodite Grmilandica, Smipsox, Shells of New l^ULilaiKl, 19 (1851). 



Serripes Groenlandicum, Chenu, Man. de Conch, ii. 109, figs. 496-498 (1862). 



Serripes Gncnlandicus, Packard, Labrad. Mar. Anini. 23. 



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

 pressed ; ])eaks uot very prominent, curved inwards and slightly 

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

 terior part somewhat elongated, margin protuljcrant beyond the 

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

 mination a somewliat 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 ])y numerous inconspicuous, radiating ridges ; 

 epidermis thin, shining, of a drab or very light fawn-color ; hinge 

 slender ; cardinal teeth nearly wanting ; marginal teeth distinct, 



