o bivalve shells. 



Synopsis Specierum. 



I. Margine dorsali integro. 



a. Stri(B simpUces, 1-18. 



b. StrifB ad latera scabra vel lamellos<2, 19-30. 



II. Margine dorsali circumscripto. 



a. Area dorsali in medio prominente, 31-36. 



b. Area dorsali depressa, plana, 37-51. 



c. Area dorsali excavata, 52-85. 



I. Margine dorsali integro. 

 a. Striis simplices. 



1. DOSINIA CONCENTRICA. B.M. 



D. testa transverse ovata, latiore quam alta, compressa, postice 

 subproducta, eoncentrice creberrime inciso-sulcata, sulcis vix 

 profundis, area ligamenti simplici, lunula cordata; alba, epi- 

 dermide straminea induta. 

 Pectunculus fasciatus, Lister, Conch. pl. 288. f. 124. 

 Favanne, Conch. pl. 48. f. F, 3 ? 



Venus, no. 31, Schrot. Einl. t. iii. p. 165, excl. plur. syn. 

 Venus concentrica, Born, Mus. Test. p. /l- pl- 5. f. 5. 

 Chemn. Conch. t. vii. p. 10. pl. 37. f. 392. 

 Gmel. p. 3286. no. 32, excl. plur. syn. 

 Dillw. Cat. t. i. p. 196. 

 Wood, Ind. Test. pl. 8. f. 84. 

 Diconcha umbilicata, Klein, Ostrac. p. 147- no. 14. 

 Tellina lentiformis, Gronov. Zoophyl. p. 264. no. 114. 

 Cytherea concentrica, Lamk. An. s. Vert. t. v. p. 573. 



Desh. Ency. Meth. Vers, t. ii. p. 58. no. 21 ; in Lamk. An. 



s. Vert. t. vi. p. 316. no. 50. 

 De Kay, Zool. de Neio York, t. v. p. 216. 

 Artemis concentrica, Gray, Cat. Cyth. Analyst, t. viii. p. 309. 

 Reeve, Conch. Icon. pl. 2. f. 8. 

 Phil. Abhild. Conch. Cyih. p. 5. no. 6, 

 Sow.jun. Thes. Conch. p. 655. no. 1. pl. 140, f. 1. 

 Conrad, Cat. of Shells in Tampa Bay, SiUiman's Journ. 

 ser. 2. p. 393. 

 Hab. America centralis, loco Tampa Bay dicto. 



2. DOSINIA SEMIOBLITERATA. 



D. testa orbiculari, paulo altiore quam lata, subasquilaterali, len- 

 ticulari, depressiuscula, albo-lutescenti, zonulis transversalibus 

 inaequidistantibus translucidis notata, transversim sulcata, sul- 

 cis planis, latis, in medio obsoletis obliteratis; umbonibus acutis 

 prominentibus subrectis ; lunula elongata, acuminata, vix de- 

 pressa, leevigata, per longitudinem concava; valvis intus albis; 



