138 PALEONTOLOGY OP NEW JERSEY. 



tion slightly carinate, and the axis imperforate ; surface marked by numer- 

 ous slender, longitudinal ribs or varices, which are erect, closely arranged, 

 and directed obliquely backward in passing from the upper to the lower 

 side of the volutions; minute surface structure not visible on the specimen 

 in hand. 



The specimen which I have used in the above description is quite im- 

 perfect, and does not possess many of the specific features of the shell 

 above named, consequently I am in doubt as to the correctness of the iden- 

 tification; but as far as the features are retained they agree very well with 

 those given by Mr. Gabb. Mr. Gabb's specimen was also quite imperfect, 

 and were it not for his statement that it came from the white limestone, I 

 should have supposed this one to have been his type, as it is from the col- 

 lection Acad. Nat. Sci., Phila. This one, however, does not show any trace 

 of the umbilicus, nor of a thickened lip. It differs very materially from 

 S. Sillimani in its smaller apical angle, being a more slender shell; by its 

 shorter volutions and more compact form, and by the more numerous lon- 

 gitudinal folds or varices, they being nearly or quite double those of that 

 one in number. 



Formation and locality : The specimen used is from dark-colored green- 

 sand, apparently of the Lower Marls, and is labeled "Cret. N. J., Abbott," 

 below which is added in pencil ^^Scala Sillimani," all in what I should take 

 to be Mr. Conrad's handwriting. The identification with ^S'. Sillimani is 

 certainly an error. Mr. Gabb's specimen, he says, was from the white 

 limestone of New Jersey, which I take to be the white limestone nodules 

 from the Lower Marls. 



ScALARiA Sillimani. 

 Plate XVIII, Fig. 3. 



Scalaria Sillimani Morton : Synop. Org. Rem. Cret., p. 47, PI. xiii, Fig. 9. 

 Scala SiUimani (Morton) Gabb: Synopsis, p. 79; Meek, Check List Cret. and Jur. 

 Foss., p. 20. 



Shell of medium size, measuring nearly one inch in length and rapidly 

 tapering, the apical angle being about 30° or 35°; volutions five or more, 

 very round and full, but closely compacted; the suture line deep and 



