286 TRANSACTIONS OF THE WAGNER FREE 



by the courtesy of Mr. Aldrich in lending a specimen which preserves the 

 aperture, I have been able to supply the deficiency. Some doubt has been cast 

 upon the generic place of this species, which this illustration will remove. It 

 has been supposed that Rostellaria Whitfieldi Heilprin (Proc. Acad. Nat Sci. 

 Phila. for 1879, p. 216, pi. xiii. fig. 14) was the adult form of C. viiictum. An 

 inspection of a specimen of R. Wliiifieldi in the National Museum shows, 

 however, that this is not the case ; but the last- mentioned species is probably 

 a Ceritliium of the same group as C. vincUini, but growing to a much larger 

 size. 



A few other species of large Cerites are known from the American 

 Eocene; one from Prairie Creek and another from Red Bluff are about to be 

 described by Mr. Aldrich. C. texanum Heilprin,* described from a frag- 

 ment, is probably not a Cerite ; it has more the appearance of a gigantic 

 Melanian, like some of the East Indian forms. A much better specimen than 

 Heilprin's was collected by Singley near Wheelock, Texas. This shows that 

 the spire is not so rapidly tapered and short as supposed by the describer. 

 The pillar is arched and simple as in Goniobasis, with no trace of the spiral 

 ridges which appear in the giant Cerites of the Parisian Eocene. 



Genus POTAMIDES Auct. 

 The whole synonymy of the Cerites is in great need of revision. This 

 genus is usually ascribed to Brongniart, but I have not found any evidence 

 that he used anything but a French name for the group. There is no doubt 

 that Lamarck, Link and others used the name Cerithium for the group some- 

 times called F«Ya^«j / Lamarck's sole type in lygg -was Murcx altico Linne, 

 which is also the type of Vertagus. Pyrazus of Montfort was not founded on 

 the species palustris, as his figure shows ; though he confounded his P. Bau- 

 dini with the Stronibiis palustris of Linne. But it is not practicable to review 

 the synonymy at this time, and I shall not attempt it, but shall adopt the names 

 in common use, although most of them may eventually have to be changed 

 when a rigid application of the rules of biological nomenclature is made to 

 the group. 



Potamides hillsboroeneis Heilprin. 

 Plate 15, figure 12. 

 Cdtilhium hilhboroensis Heilp., Trans. Wagn. Inst. i. p. 124, pi. 8, fig. 67, 1887. 



Older Miocene of the Orbitolite bed at Tampa, Willcox, Dall ; and at 

 Chattahoochee, Burns. 



This species is found in the lower or older Miocene (Tampa limestone) 

 rocks of the Hillsborough River, and of the Ocheesee group in Northwest- 

 ern Florida. The original figure was very bad and I have had the type re- 



* Proc. Acad. Kat. Sci. Phila. for 1890, p. 404, pi. .xi. fig. 2. ' 



