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 Mullica Hill, and other places in New Jersey. 
NATICA, 
Casts of a small indeterminate species. 
BULLA? 
Globose, with numerous transverse strie. Length one inch. Casts 
only are found, and I may be wrong in referring them to the above 
genus, 
3 | 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 Vermetus extremely like 
the specimens in question: vide pl. 596, figs. 4, and 5. 
SERPULA. 
=e friend, Dr. McEuen, procured a number of Serpule a 
Seren, &e. in yellowish brown marl, two miles west of Long Branch. 
= same locality abounds in Terebratula Harlani. 
cyPpreza. Lin. 
A solitary cast of this genus was found at the Chesapeake and Del- 
aware canal, It is Ss how in the possession of Mr. John Finch. 
