^g POST-PLEIOCENE FOSSILS. 



slif^htly, and concavely curved ; whereas, in the recent species, T. Burnetti, the left 

 val've is flat, the right concave, and the posterior dorsal margin very deeply curved ; 

 the dentations are also more profound. We have been careful in giving a number of good 

 fio-ures of these two species, as they have been confounded for a long time. 



Plate IX. Fig. 6, T. Burnetii, left valve. 



" 6a, T. Bur7ietti, interioi; right value. 



" 6*, To sho7V convexity of right valve. 



" 7, T. lunulata, right valve. 



" Ha, T. lunulata, left valve. 



" Ih, Interior, left valve. 



" 7c, Interior, right valve. 



" Id, To sho7v convexity of left valve. 



Locality. Simmons'; Brown's, St. Andrew's. 



Museum, College of Charleston; Cabinet F. S. II. 



Genus, MACOMA. — Leach. 



M A C M A F U S C A . 

 Plate VIII. Fig. 5. 



Psammobia fusca, Say, Jour. Acad. Nat. Sci., Vol. 5, p. 220. 



Sanguinolaria fusca, Con., Am. Mar. Conch., p. 34, pi. 7, fig, 1. 



Sanguinolaria fusca, Gould, Invert. Mass., p. 66, fig. 42. 



Sanguinolaria fusca, De Kay, Zool. New-Vork, Art. Mollusca, p. 212, pi. 32, fig. 304. 



Sanguinolaria fusca, Ravenel, Cat. Coll. Shells, p. 3. 



Sanguinolaria fusca, L. R. Gihbes, Tuomey's Geol. So. Ca., appendix, p. xxi. 



Sanguinolaria fusca, Jay, Cat. Coll. Shells, 4th Ed., No. 565. 



Tellina fusca, Stimpson, Shells New-England, p. 20. 



Macoma fusca, Adams, Gen. Recent Mollusca, Vol. 2, p. 400. 



Psammobia fusca, Say's Conch. U. S., (Binney,) p. 126. 



Description. Shell thin, compressed, transversely ovate, equilateral, concentrically 

 and distinctly striated; strife somewhat wrinkled; beaks small, not prominent, central; 

 buccal margin rounded; anal margin narrowed, somewhat pointed; a fold extends from 

 beaks to point of anal margin, which is obtusely rounded ; two small unequal teeth in 

 each valve. 



