VENERID^. 33 



This little species is at once known by the regular and angular furrows; straight sides, 

 and prominently arched pallial margin, which is smooth within. 



It occurs living on the coast of New-England, South-Carolina, and in the Gulf of 

 Mexico. 



Plate VI. Fio. 9, Natural size. 



Locality. Simmons'. Museum, College of Charleston; Cabinet F. S. II. 



Genus, MERCENARIA. — Schumacher. 



MERGE N ARIA VIOLACEA. 

 Plate VI. Fig. 11. 



Venus mercenaria, Linn., Syst. Nat., 1131. 



Venus mercenaria, Gmelin, 3231. 



Venus mercenaria, Lam., An. sans Vert., Vol. 6, p. 346. 



Venus mercenaria, DiU, Cat., Vol. 1, p. 176. 



Venus mercenaria, Wood, Index, pi. 7, fig. 40. 



Venus mercenaria, Gould, Invert. Mass., p. 85, fig. 67. 



Venus mercenaria, De Kay, Zool. New- York, Art. Mollusca, p. 217, pi. 27, fig. 276. 



Venus mercenaria, Ravenel, Cat. Coll. Shells, p. 4. 



Venus mercenaria, L. R. Gibbes, Tuomey's Geol. So. Ca., appendix, p. xxi. 



Venus mercenaria, Stimpson, Shells New-England, p. 19. 



Venus mercenaria, Tuomey S^ Holmes, Pleiocene Foss. So. Ca., p. 81, pi. 21, fig. 6. 



Mercenaria violacea, Adams, Gen. Recent Shells, Vol. 2, p. 419. 



Description. Shell solid, obliquely cordate, concentrically furrowed, radiately striate, 

 anal side somewhat produced, angled; buccal side short, rounded; umbones recurved; 

 lunule heart shaped. — T. Sf II. 



The anal slope is comparatively straight, and where it joins the pallial margin, it is 

 slightly produced into a flattened lip. 



This species attains considerable size, and then resembles Mercenaria mortoni, {Con.) 

 It is the common clam of the coast; it existed in South-Corolina during the Pleiocene 

 and Post-PIeiocene periods. 



Plate VI. Fig. 11, Right valve, natural size. 

 " 11«, Lunule, natural size. 



9 Museum, College of Charleston; Cabinet F. S. H. 



