40 E. W. Hilgard on the Tertiary formations 
to this group, neither Wailes, who resided amongst them and 
gave the name of “ Davion rock” to one variety of the former; 
nor myself who have delved in scores of exposures, have ever 
found a trace of any fossil whatsoe 
The Natchez bluff I have not visited but Wailes, _ resi- 
ded within six miles of it, must have e done s so, and he is silent 
on the subject of any but the Loess fossils, although na men- 
tions all other fossiliferous rocks occurring in the S State. Thus, 
while I have seen mentioned in various plate ¥ marine strata at 
the foot of Natchez bluff,” I cannot trace the report to any au- 
thentic source. I shall a os to settle the point as soon 
possible, but meanwhile observe, that according to reliable infor- 
mation given me, the Rodne y bluff is essentially a counterpart 
of that at Grand Gulf; a detailed profile of which, obtained at a 
medium stage of the river, is given in my Report (p. 148), 
The extreme scarcity of fossils in this formation is the more 
remarkable, as from the regularity of its stratification it is man- 
ifest that it has been formed in quiet water, and it contains a great 
variety of materials suitable for the preservation of either fauna 
or flora. Even the*strata containing carbonate of lime, however, 
seem to have had nothing to fossilize, save in the solitar ry in- 
stance of a doubtful fragment of cellular bone already mentioned. 
In some portions of it, we might imagine that the abundance o 
soluble salts (which perv ade more or less the entire deposit) indi- 
cated the former existence of bitter lakes, incapable of harboring 
life; but this could by no means apply to the formation as a 
whole 
The only probable presumption in favor of referring it to the 
Eocene, so far as I know, arises from the lithological resem- 
blance and transition of its strata, at its northern limit, to those 
of the Vicksburg group. The upper division of the latter group 
in the neighborhood of Brandon is undistinguishable from the 
peas of the Grand Gulf group at Sark 6 points, and |] 
nts to mere 
toward the scaheh the lithological <hinaition sine the mate- 
rials of the “Coast pliocene” seems about equally cogent. The 
mere fact that tree palms are found in the formation, amounts to 
nothing, inasmuch as these grow at the present time in the same 
latitude in South Carolina. 
he existence of this formation in Alabama _appears from Mr. 
Thornton’s notes (2d Rep. Ala., Appendix), in which he men- 
tions similar materials as over] ying the (Vicksburg) marine Ter- 
