NATURAL SCIENCES OP PHILADELPHIA. 367 



from a common base. Interior of the tube closed at certain points by a trans- 

 verse septum. Animal unknown. 



I place this genus near Vermetus, from the statement made by Pictet, that 

 "Les tubes des serpules sont completement libres, tandi3 que les coquilles des 

 vermets sont coupees par de petites cloisons interieures transverses, que forme 

 l'animal a mesure qu'il s'accroit." 



H. and A. Adams, in their "Genera of Recent Mollusca, however, do not 

 mention these partitions. 



P. Americana Gastroch.ce.na id., nob. Jour. Acad. 2 ser., vol.4, p. 393, 

 pi. 68, fig. 20. 



Since describing this species, I have obtained specimens, retaining large por- 

 tions of the shell, and which prove that this is a second species of the same 

 genus. The figure quoted above, taken from a cast, illustrates the form. The 

 shell is thin and smooth. The septa: are as thick as the outer wall, placed at 

 distances varying from half an inch to two inches or more. The convexity, as 

 in the above form points towards the larger end. This species is much larger 

 than the preceding. I have seen one tube having a diameter of -7 inch at its 

 broadest extremity. 



Not rare in the Ripley Group of x\labama and Mississippi, and found, as casts, 

 in the yellow limestone of Timber Creek, N. J. 



Descriptions of New Species of American Tertiary Fossils and a Hew 

 Carboniferous Cephalopod from Texas. 



BY W. M. GABB. 



Phos Montf. 



P. b ell ali ratu s. Shell robust; spire elevated, whorls eight. First 

 three smooth and polished, subsequent ones marked by numerous longitudinal 

 angulated ribs, of which there are about twenty on the body volution. Be- 

 tween them, the interspaces are regularly concave. These are crossed by re- 

 volving lines, about fifteen to eighteen on the body whorl, nine or ten of which 

 are visible on the preceding ones. Suture small but distinct, and bordered by 

 a prominent, undulated rib ; the whole surface of the shell being crossed by 

 well marked lines of growth. Mouth short, rather wide. Outer lip acute on 

 the edge, thickened behind and internally striate. Inner lip covered with a 

 thick coat of enamel, smooth and polished. Canal short, deeply notched and 

 with a large fold on the truncated edge of the columella. 



Length, -6 in.; width of body whorl, -3 in.; length of mouth, -24 in. 



From the Eocene of Claiborne, Ala. Coll. Acad. 



From P. Texanus, nob., the nearest allied form, this species can be distin- 

 guished by the more robust shape, lower spire, absence of the occasional ten- 

 dency to form pseudo-varices, or peiiodical arrests in growth; the broader 

 mouth and the perfectly smooth columellar lip, which, in the latter species, is 

 marked by a few irregular polished thickenings or teeth. The notch, at the 

 end of the canal is deeper and more oblique, the longitudinal ribs are more pro- 

 minent, acute, fewer in number and placed further apart. P. Texanus has dis- 

 tinct revolving ribs ; in the prespnt species these are mere imbrications, abrupt 

 above and sloping anteriorly to the edge of the succeeding ones, except near the 

 canal, where the last two or three take the form of libs. 



Voluta Lam. 



V. s i n u o s a. A fragment, in the collection of the Academy, from the 

 Miocene, either from Virginia or North Carolina, displays such strong specific 

 characters, that, notwithstanding its mutilated condition, I shall venture to 



1861.] 



