8 PALEONTOLOGY OF NEW JERSEY. 



transverse wavy lines, which, if it were a constant feature, would serve to 

 distinguish them, but even on the specimen where this feature is most 

 marked, I find that it varies even on different laminae of shell over the same 

 space where it has been exfoliated artificially, so that it forms no positive 

 means of distinction. I am inclined, therefore, to regard it only as a very 

 strongly marked variety, and not a valid species. 



Yeirietj perovalis^ PL I, Fig. 19. This form Dr. Morton identified with 

 the European shell T. perovalis Sowerby, but it can be nothing more than a 

 two -thirds grown form of T. Harlani, and the name has long since been 

 dropped out of the literature by most authors. He afterwards proposed the 

 name T, camella for it, if found to be distinct from T, Harlani. 



Terebratula Harlani is about the largest terebratuloid shell known in 

 American rocks, and is one of the most beautiful, as well as the most abun- 

 dant. At several localities where it is found, it occurs in immense numbers, 

 forming, in connection with Gryphcea vesicularis, nearly or quite half the 

 substance of beds of several feet in thickness. At the marl pits, about 

 one and a half miles from New Egypt, they are found through about 

 eight feet of sandy marl so densely packed together that it is almost im- 

 possible to extricate specimens without breaking, and in certain parts of the 

 bed the marl forms much less than half the bulk of the whole. Through 

 about two or three feet of the upper part of the bed the Terebratula is 

 almost alone, mostly in separated and water-worn valves, but near the 

 upper portion of this thickness perfect shells can be obtained in great numbers. 

 The Terebratula bed is an excellent line for comparison of the strata at differ- 

 ent localities, and has been traced throughout a large part of the State and 

 into Delaware. The shell has been obtained from South Carolina, where 

 it is said to be found in the Tertiary. This I think extremely doubtful, as 

 it is never found above the middle marl beds in New Jersey. Moreover, 

 the strata in South Carolina are in such a position that it may easily be ob- 

 tained from the Cretaceous layers below without the fact being detected. 

 Specimens in Dr. Holmes' collection in the American Museum of Natural 

 History certainly present all the appearances of the Cretaceous shell, but 

 are larger than any I have seen from New Jersey. Mr. Gabb, in his Synop- 

 sis, cites T, atlantica Morton as a synonym of this, considering it as a 



