282 Organic Remains of the Ferruginous 



careous marls of Gloucester county, N. J. This fossil has the ex- 

 ternal aspect of a chambered shell. 



ROSTELLARIA. 



Casts about an inch in length, with ten or twelve elevated longitu- 

 dinal ribs. Abundant in the argillo-micaceous beds of the Chesa- 

 peake and Delaware canal. Much larger specimens of the same 

 species occur at MuUica Hill, and other places in New Jersey. 



NATICA. 



Casts of a small indeterminate species. 



BULLA ? 



Globose, with numerous transverse striae. Length one inch. Casts 

 only are found, and I may be wrong in referring them to the above 

 genus. 



TROCHUS. ^ 



Indeterminate casts, and even these are of rare occurrence. 



SPIRORBIS ? 



This shell, which I have lately discovered in the calcareous marls 

 of New Jersey, I have not yet had leisure to examine with attention. 

 Description. Volutions four or five in number, in contact through- 

 out : aperture quadrangular, which form is preserved in all the whorls : 

 diameter of the largest specimens three eighths of an inch. It has 

 a strong resemblance to Planorbis : Mr. Sowerby mentions that he 

 found shells in the English green sand, which he referred to that 

 genus, though, he thinks erroneously. I prefer placing the Ameri- 

 can specimens with the genus Spirorbis, until more information can 

 be obtained respecting them : although a late number of Sowerby's 

 work contains figures of some species of J^ermetus extremely like 

 the specimens in question: vide pi. 596, figs. 4. and 5. 



SERPULA. 



My friend, Dr. McEuen, procured a number of Serpulce attached 

 to Ostrea, Sic. in yellowish brown marl, two miles west of Long Branch. 

 The same locality abounds in Terehratula Harlani. 



Li 



m. 



A solitary cast of this genus was found at the Chesapeake and Del- 

 aware canal. It is now in the possession of Mr. John Finch, 



