TERTIARY FOSSILS. 113 



The above list gives no means of determining where this species was described; 

 and I can find no form to which to refer it, unless it be one of the succeeding, 

 both of which have been placed under the same specific name. 



CASSIDEA, Swains. C. ? BILIRATA, Con., sp. 



Semicassis? biliratus, Con. ; Sm. Check List (1866), No. 472. 

 Doliopsis id., Con. ; Jour. Conch., 1865, p. 150. 



Dolium petrosum, Con. ; (pars) Wilkes's Exped., p. 727, pi. 19, fig. 4. 

 Miocene, Oregon. 



C. ? PETROSA, Con., sp. 



Semicassis petrosus, Con. ; Sm. Check List, No. 474. 



Doliopsis id., Con. ; Jour. Conch., 1865, p. 150. 



Dolium id., Con.; Wilkes's Exped. (pars), p. 727, pi. 19, fig. 3, 5. 



Miocene, Oregon. 



FICOPSIS, Con. F. MODESTA, Con., sp. 



Pyrula modesta, Con. ; Am. Jour. Sci., 1848, p. 433, fig. 12. 

 Sycotypus id., Con. ; Jour. Conch., 1865, p. 151. 

 Ficus id., Meek ; Sm. Check List, Miocene, No. 637. 

 Ficopsis id., Con. ; Sm. Check List, Eocene, No. 479. 

 . Miocene, Oregon. 



FICUS, Bolt. F. OCOYANUS, Con., sp. 



Sycotypus Ocoyanus, Con. ; P. K. E. Kep., Vol. 5, p. 329, pi. 7, fig. 72. 

 Ficus id., Meek ; Sm. Check List, Miocene, No. 635. 

 Miocene, Ocoya Creek. 



NATICA, Brug. N. GENICULATA, Con. 



Id., Con. ; P. R. R. Rep., Vol. 5, p. 328, pi. 7, fig. 67. 

 Miocene, Ocoya Creek. 



It is not impossible that this may prove to be identical with Agasoma gravida, 

 but the figure in the Pacific Railroad Report is so very uncharacteristic, that I 

 have been unable to arrive at a satisfactory opinion on the subject. 



PAL. VOL. II. 16 



