ee 
~ 
of the Walnut Hills, §c., Mississippi = 2.11 
‘Near the summit of the Eocene are beds of coarse gravel mixed 
with whole shells and fragments, from which many fine agates 
have been procured by Mr. Anderson of Vicksburg. These strata 
do not appear to have been much disturbed or inclined by the 
force which elevated them to their present level. ‘Fhe group of 
fossil shells though as strongly marked in its Eocene character as 
any in the Union, is yet remarkably distinct from that of Clai- 
bore or of any other locality which I have seen, as out of about 
sixty-two species, thirty-eight are new, and J am confident that 
ten species will on comparison be found identical with Claiborne 
‘shells. In most of the strata here, small and large fragments of 
shells are very abundant, some of which are water-worn and 
others not in the least abraded. Occasionally we find a black 
water-worn shell just.in the proportion to the others as we see 
them on the sea beach of New Jersey. The vicinity of an an- 
cient sea beach is strongly indicated by the phenomena of these 
strata, which is not the case at Claiborne.  Bivalves with con- 
hected valves are rare, fragments abundant, and the many water- 
‘Worn specimens all tend to prove the action of the surf. In the 
elay stratum of the upper portion of the formation, the shells in 
some rare instances retain a trace of their original colors and their 
: Polish is fully equal to that of recent shells, though they become 
chalky on exposure to the sun. .The large Cardita planicosta, 
which so generally prevails in Eccene deposits, is unknown here, 
and the Crassatella alta of Claiborne is also absent, but there is 
_4n allied though very distinct species... There is one bivalve 
here, anew Panopea which is common, and yet unlike the other 
bivalves is almost in every instance entire, and placed vertically 
m the Strata, just as it occurred when living and burrowing in 
the bed of the sea. It therefore lived and died on the spot where 
itis now found, whilst nearly every other shell had been abraded 
by the surf or. transported by currents. This is precisely the case 
with all the various species of Panopea in the Miocene forma- 
hon, and it is clear that they burrowed deeply in the mud or 
sand beyond the influence of the agitated waters which scattered 
the various shells at that time existing near the surface. 
The principal development of the Eocene is north of Vicks- 
burg, and every ravine cuts through its various strata, but it is 
inaecs | impossible to procure an accurate section of them, as they 
ate universally sunk and displaced by land slides and subsidence. 
