TRIBE CARDIACEA. 141 



C. Elenense. So7v. Jiin. Z. P. 1840.— C. /. /. ;)%. 

 Thin, smooth, oval, subacuminated anteriorly, pale fulvous with 

 brown and purple dots, the inside brown with red bands ; umbones 

 not prominent, spotted with purple. f..|- — TT^, Columbia. — 

 Very like Brasilianum. 



C. SuBSTRiATUM. Conr. Jour. A. N. S. Phil. 7. p. 228. 

 t. 17. f' 2. Obliquely ovate, ventricose, thin, smooth, with the 

 radiating strise obsolete except at the base of the umbonal slope, 

 yellowish variegated with brown, umbo and middle of the disc 

 tinged with blue : inside yellow varied with brownish purple, 

 markings, the margin finely serrate. J. — W. California. — Pos- 

 sibly the young of another species. 



C. MoRTONi. Conr. Jour. A. N. S. Phil. G. t. 1 1. /*. 5, 6, 7- 

 — Gould. Mas. p. 91.— C. I. f. 53, 4? Subovate, oblique, 

 subventricose, thin, destitute of ribs or radiating striae, white under 

 a pale brown epidermis, darker towards the margin, and wrinkled 

 at the ends : inside striated, yellow, the margin entire or obsoletely 

 serrated and whitish, generally an oblong black or dark purple spot 

 on the anterior side. 1 . . 1 . — United States. 



C. Fragile. Sotv. Jun. Z. P. 1840.— C. I.f. G8. Rounded, 

 thin, smooth, subequilateral, slightly inflated anteriorly, white 

 lineated with brown under a fulvous epidermis ; within white, and 

 reddish at the margin ; yellow at the umbones ; margin slightly 

 grooved. 1 . . 1-J^. 



C. Lyratum. So7v. Jun. Z. P. 1840.— C. I. f. 40. Ven- 

 tricose, rounded subequilateral, pale fulvous under a purplish red 

 epidermis, within golden yellow ; posteriorly decussated with plaits, 

 the ribs numerous, the posterior very fine, the central stronger, 

 the anterior distant and angulated. I^'y..lJjj. — Philippines. — 

 Closely resembling Eolicuni, but without the smooth anterior area. 



* * Beaks carinated or provided with an angle ; posterior side 

 often longer than the anterior. 



C. Unedo. Lin. 1123.— i>.j?. 119.— iam. 39.— Ch.f. 168, 

 9.—E. t. 295. f. A.— Wood. G. C. t. 58. /. S.—W.t. 5. /. 50. 

 Somewhat heart-shaped, rounded, turgid, the anterior extremity 

 forming an angle above and projecting ; white, with numerous 

 purplish red crescent-shaped elevated markings on the polished and 

 rounded ribs : margin strongly serrated anteriorly. 2 . . 1^. — E. 

 Indies. 



C. Medium. Lin. 1121.— Z). p. \U.—Lani. A0.—W.f.5. 

 f. 5.-Ch. f. IG2, 3, 4.—E. t. 296. f I.— Wood. G. C. t. 50. 

 f. 3. — Somewhat heart-shaped, turgid, whitish clouded and spotted, 

 with rufous and brown, max-ked with strong longitudinal rounded 

 ribs, which are separated by almost equally broad furrows and 

 crossed by minute transverse striee ; the anterior side is somewhat 



