1845.] 



553 



species now living, and he supposed that a somewhat larger propor- 

 tion would be identified, were our knowledge of the living mollusca 

 more perfect. 



I shall confine myself to remarks on those shells, amounting to 

 147 species exclusive of Balani, which I collected myself, and 

 which I have carefully compared, with the assistance of Mr. G. B. 

 Sowerby, with the tertiary shells of Europe, and with recent 

 species. 



The following table will show the miocene genera above alluded 

 to, and the number of species in each : — 



Miocene Mollusca of Virginia and South Carolina. 

 Marine Univalves (63 species). 



Of the 147 species above enumerated, I have been able to iden- 

 tify the following 23 with recent species : — 



American Miocene Shells identified with Recent Species. 



Purpura lapillus Lin. Petersburg, yirginia. 

 Fusus cinereus Lin. Petersburg, Virginia. 

 Pyrula (Fulgur) carica Say. Petersburg, "Williamsburg, &c. 

 P. canaliculata Say. Maryland. 

 Natica duplicata Say. Petersburg, &c. 

 N. heros Say. Maryland. 



Calyptraa costaia. Wilmington, North Carolina, (Syn. Bispotcea ramosa 

 Conrad. ) 



Identical with a recent species which I have from Valparaiso. 

 Crepidula fornicata Ijam. Williamsburg. 

 Dentalium dentalis. Wilmington. 

 Ditrupa gadus. Williamsburg, Maryland ; and Petersburg, Virginia. 



T T 4 



