SECTION II. 



CRETACEOUS GASTEROPODA OF THE MIDDLE MARL BEDS OF NEW 



JERSE x • 



MURICIDiE. 



Genus PERISSOLAX Gabb. 



Perissolax trivolva. 



Plate XXI, Figs. 1-3. 



Fusus trivolvus Gabb: Proc. Acad. Nat. Sci., Phila., 1860, p. 94. 

 Perrissolax trivolva Gabb : Synopsis, p. 67 ; Meek, Check List Cret. and Jur. 

 Foss., p. 23 ; Geol. N. J., Newark, 1868, p. 730. 



Shell of medium size, ventricose, with a long, straight canal, once 

 and a half as long as the length of the inner part of the body whorl 

 above it. Spire very low, broad, conical; the apical angle being from 100° 

 to 110°, the top of the volutions flattened in the direction of the slope of 

 the spire, and the inner volutions barely rising above the outer ones. Body 

 whorl flattened on the periphery, forming a nearly vertical, flattened band 

 of considerable depth, below which a second obliquely flattened space of 

 somewhat less width occurs, thus forming the three angles on the body of 

 the whorl from which the name was derived. Below the lower angle 

 the surface slopes rapidly to the long, slender canal and beak. Aperture 

 large, angular on the outside and contracted below at the canal, strongly 

 modified on the inner margin by the preceding volution. Volutions faintly 

 marked by distant varices and along the upper carina by a series of thin, 

 rather closely arranged transverse nodes. No fine surface markings or 

 spiral lines are perceptible on any of the specimens, all of which are internal 

 casts in a rather coarse yellow lime sand. 



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