MOLLUSCA. 753 



flattened above in a spiral band just below the suture, the outer 

 margin of the flattened band being elevated in a moderately- 

 strong revolving rib, below this rib the outer volution is nearly 

 regularly convex to the base of the anterior canal which is rather 

 elongate and slender; surface of the outer volution marked by 

 about six or seven strong, revolving ribs between the outer mar- 

 gin of the flattened band above and the base of the anterior beak, 

 the outer half of the volution being also marked by several, 

 rather strong, vertical varices which are about twice as far apart 

 as the revolving ribs, these varices dO' not cross the flattened 

 band above, and at their junction with the revolving ribs they 

 are elevated into rounded nodes; entire surface of the shell also 

 marked by somewhat irregular, transverse lines of growth. On 

 the internal casts the transverse varices are well marked, but 

 the revolving ribs are faint except at the junction with the 

 varices; the columellar cavity narrow. 



Remarks. — ^This species most closely resembles P. whitHeldi, 

 but, besides being confined to an entirely different geologic 

 horizon, the flattened upper margin is more distinct, the vertical 

 markings are more remote varices in the outer half of the last 

 volution of the adult shells rather than regular ribs covering 

 the entire shell with a distance apart about equaling the spaces 

 between the revolving ribs. Furthermore, the vertical varices in 

 P. lenolensis end at the outer margin of the upper flattened 

 spiral band, while in P. whitHeldi the ribs apparently continue 

 to the suture, judging from the internal casts alone. 



Formation and locality. — Merchantville clay-marl, Lenola 



(163). 



Geographic distribtUion. — New Jersey. 



Genus EuThria Gray. 



Euthria ? fragilis Whitfield. 



Plate LXXXVIIL, Figs. 25-26. 



1892. Buthria ? fragilis Whitf., Pal. N. J., vol. 2 (Monog. 



U. S. G. S., vol. 18), p. 78, pi. 9, figs. 11-12. 

 1905. Buthria ? Fragilis Johns., Proc. Acad. Nat. Sci. Phil. 

 (1905), p. 23. 



48 PAIv 



