146 PALEONTOLOGY OF NEW JERSEY. 



others with which it is associated in the New Jersey beds, in the flat- 

 ened volutions and in the surface characters. In some of the casts the 

 upper whorls are somewhat rounded from the greater amount of deposit 

 on the inside of the older parts of the shell, but they never attain that 

 degree of wide separation of the volutions, with wide sutures, that is 

 common in T. vertebroides ; while even in the most thickened specimens 

 the lower whorls show the rectangular form of the volutions, and usually 

 retain some evidence of the spiral lines. The general aspect as furnished 

 by these casts indicates a thin and rather delicate shell, instead of the 

 thick, heavy shell of T. vertebroides and T. encrinoides. 



Formation and locality : In the Lower Green Marls at Crosswicks 

 Creek, near New Egypt; at Upper Freehold; Holmdel and Walnford, 

 New Jersey. 



TURRITELLA VERTEBROIDES. 



Plate xvin, Figs. 13-18. 



Turritella vertebroides Morton: Synop. Org. Rem. Cret., p. 47, PI. in, Fig. 13; 

 Gabb, Synopsis, p. 92; Meek, Check List Cret. and Jur. Foss., p. 19; GeoL 

 N. J., Newark, 1868, p. 739. 



Shell much elongated and slender, the apical angle in an uncompressed 

 internal cast of large size being about 12°; volutions slightly convex on 

 the exterior, when retaining the substance of the shell, nine or ten in num- 

 ber, and tnarked on the surface by five or more sharply elevated spiral 

 ridges, and apparently with finer lines on the interspaces and with fine 

 transverse lines of growth crossing them. Sutures moderately distinct, 

 but not channeled or grooved. Aperture unknown. On the cast the volu- 

 tions are widely separated, indicating a considerable thickness of shell, and 

 their form is obliquely rounded, larger and subangular near the lower mar- 

 gin as they approach the lower end of the shell, but more distinctly circular 

 and proportionally more slender in the upper part; probably from the 

 greater thickening of the shell on the inside. The surface features are only 

 indistinctly marked on the larger part of the casts, a single spiral groove 

 in the upper part indicating a strong feature of the shell at this part. 



The specimens of this species which retain the surface features are 

 very few and badly preserved, being mostly in a pyritous marl which rap- 

 idly disintegrates on exposure. They are usually more or less compressed 



