78 PALEONTOLOGY OF NEW JEKSEY. 



Formation and locality : All the specimens of the species yet observed 

 are from the dark green layers of the Lower Green Marls at Crosswicks, 

 New Jersey, and were collected by Dr. N. L. Britton for the State survey. 



Genus EUTHRIA Gray. 



EUTHRIA ? FRAGILIS, n. Sp. 



Plate IX, Figs. 11, 13. 



Shell small, measuring only about three-fourths of an inch in length; 

 form short fusiform, the point of greatest diameter being nearly midway of 

 the length; spu-e short, the apical angle, taken from a crushed example, 

 being about 70°, probably not more than 60° to 65° in perfect sjjeci- 

 mens; volutions ventricose, six or seven in number, the last one forming 

 the great bulk of the shell and with the anterior beak forming about five- 

 sevenths of the entire length when measured on the back of the volution; 

 upper volutions compact; sutures strongly marked; anterior beak short, 

 moderately strong; aperture not seen; substance of the shell very thin and 

 fragile, marked only by fine lines of growth parallel to the margin of the 

 aperture, which indicates the existence of a broad and rather marked sinus 

 in the lip on the upper side of the volution, formed by the extension of the 

 lip below and on the body of the volution far in advance of the margin at 

 and just below the suture; on the surface of the beak the strise gently 

 inclined backward again. 



This species is well marked in its characters as compared with other 

 New Jersey cretaceous shells, so that .there will be no difficulty in recog- 

 nizing it. Mr. Gabb describes a somewhat similar form from the Ripley 

 group in Hardeman County, Tennessee, under the name Neptunea impressa, 

 but the spire is somewhat shorter, and he describes the shell as marked by 

 impressed spiral lines which do not exist on this shell. He furthermore 

 states that the columellar lip is covered by^ "a somewhat heavy layer of 

 enamel." This one may have possessed such a feature, but the condition 

 of the specimens will not permit of an examination of that part, but no 

 such appearance exists so far as can be seen. There may be some question 



'Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 4, p. 390, 



