MARINE MOLLUSCA OF THE UNITED STATES. 169 



2. L. pusiLLA, Goukl. 



Proc. Bost. Soc. Xat. Hist., viii. 282. 1862. 



Shell minute, reniform, 3'ellowish, slightly coucentrically striate; 

 umbones a little posterioi", elevated ; anterior dorsal margin exca- 

 vated, extremity retusely rounded ; posterior extremity broadly 

 rounded, subtruncated ; within radiatingly striated, the striae 

 evanescent towards the umbones. 



Length 3, height 2.5 mill. 



Goa&t of North Carolina. {Coast Stircey.) 



3. L. DENTATA, Wood. Fig. 427. 



Gen. Couch., 195, t. 4G, f. 7. 1817. 

 Lucina strigilla, Stimpsou, Shells N. E., 17. 1851. 

 Lucina Americana^ C. B. Adams, Contrib. Conch., 243. 1852. 

 Lvcina-divarieata, Lamarck (not Linn.), Anim. s. Vert., v. 541. 1818.' 



Shell thin, orbicular, equilateral ; beaks small, prominent, 

 inclined forwards; basal margin regularly rounded and crenate. 

 Surface with well-marked concentric-lines, crossed by deep, oblique, 

 narrow furrows, flexed at nearly right angles at the anterior third 

 of the surface. White. 



Length 25, height 22 mill. 



Entire Coast. {Distribution universal.) 



4. L. TiGERiNA, Linnoeus. Fig. 428. 



Syst. Nat., edit. xii. 1133. 1767. 

 Shell oblong-ovate, longer than high, flatl}' convex, radiately 

 man)' grooved, very closel}^ decussated throughout with concentric 

 ridges ; white within and without. 



Southern Coast. (W. Ind.) 



5. L. EDENTULA, LiuutBUS. Fig. 429. 



Mus. Ulric, 74. 

 Lucina chrysostoma., Phil. Zeit., Malak., ii. 181. 1845. 



Shell orbicular, rather thin, ventricose, superficially excavated 

 from the umbones on each side, concentrically finely and closely 

 striated, teeth obsolete; semitransparent white, orange within. 



Southern Coast. ( W. Ind. ) 



' For full ^3'nonymy and notes on this species, see Tryon, Proc. Philad. 

 Acad., 80. 1872. 



