MOLLUSCA. 751 



upon the casts, which are crossed by vertical ridges at about 

 equal intervals or slightly more distant than the spiral lines, the 

 twO' sets of markings dividing the surface into a number of 

 square, depressed spaces ; anterior beak short, apparently straight, 

 and rather pointed ; aperture elongate, pointed above and belovi^, 

 about half as wide as long. In the casts the suture is distinct 

 and often strongly marked. 



Remarks. — This species is of about the same size as P- retifer, 

 from which it may be distinguished by the distinctly flattened 

 band on the upper side of the volutions adjacent to the suture; 

 the spire is also slightly more depressed, and the lower side of the 

 outer volution contracts a little more rapidly to the anterior beak. 

 The species has only been seen in the condition of internal casts, 

 and by Whitfield was referred to P. octolirata. It differs from 

 P. octolirata, however, in the presence of vertical ribs, and appar- 

 ently also in the flattening of the upper margin of the volutions. 



Formation and locality. — Navesink marl, Crosswicks Creek 

 (195), near Walnford (Coll. N. -J. Geol. Surv.). 



Geographic distribution. — New Jersey, Alabama. 



Pyropsis octolirata (Conrad). 

 Plate LXXXVIIL. Figs. 17-18. 



1858. Ficics octoliratus Con., Jour. Acad. Nat. Sci. Phil., 2nd 



ser., vol. 3, p. 332, pi. 35, fig. 6. 

 1861. Perissolax octolirata Gabb, Synop. Moll. Cret. Form., p. 



123 (67). 

 1864. Perissolax octolyrata Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 23. 

 1868. Perissolax octolirata Con., Cook's Geol. N. J., p. 730. 



Description. — Shell pyriform or, exclusive of the anterior canal, 

 subglobular in form, consisting of three or four volutions, the 

 outer one of which is produced in front in an elongate anterior 

 canal ; imperforate ; suture slightly impressed ; the dimensions of 

 a somewhat incomplete internal cast are : total height, 20 mm. ; 

 height of spire, 4 mm. ; maximum diameter of outer volution, 



