APPEND! X- 
APPENDIX A. 
DESCRIPTIONS OF 
GENERA AND SPECIES OF 
FOX 
SHELLS 
OF NORTE CAROLINA, 
IX THE STATE CABINET AT RALEIGH. 
By T. A. CONRAD. 
The Cretaceous fossils described in this paper represent the Ripley 
group of that formation, so named from the town of Ripley, Mississippi. 
Some of the species of Ripley are identical with Carolina shells, and others 
with those of Eufala, Georgia, and Haddonfield, New Jersey. Not only 
this identity of several species, but the mineral character of the beds in 
which they are found is the same, and also the state of preservation of the 
fossils, proving not only a simultaneous deposit, but a similar depth of 
water, not in an estuary, but in a marine basin. Oyster shells are very rare 
and so far only one estuary shell, a Neritina. has been found, and that in 
Mississippi. I conclude, therefore, that the Ripley ocean extended over 
most of the Southern States, bordered on the north by the Triassic, Car- 
boniferous and older rocks, and that the materials which drifted into the 
Cretaceous sea, were derived in all localities from a similar source, since 
the marl is a tine, brown sand, holding minute grains of transparent 
quartz, which constitutes a friable, incoherent earth, from which the most 
delicate hinges of the bivalves are easily cleared. This marl is destitute 
ot green sand in the localities referred to above. The Ripley group con- 
stitutes the great hulk of the Cretaceous strata, east of the Mississippi, and 
it corresponds most nearly in age with the Senonian stage of d’Orbigny, 
or that part of the Cretaceous series, which underlies ard most nearly 
approaches in age to the chalk. 
