ot ai co 
Eocene Fossils of the United States. 209 
Ohio for many years, if at all since the settlement of the country. 
As the lands become. more completely cleared of the forest trees, 
dry summers will doubtless be more frequent. In a region so 
near a large body of water, we should expect more rain than in 
one at a distance. The sky in that district is, nevertheless, much 
oftener covered with clouds than in the southern portion of the 
State, where rains are more abundant ; but the dividing ridge, or 
height of land between Lake Erie and the waters of the Ohio, 
lacks a range of high hills to attract the moisture from the clouds, 
and cause it to descend in showers of rain. 
For the above account of the drouth in the ‘‘ Western Reserve,” 
I am under obligation to Seabury Ford, Esq., of Granger county. 
Marietta, Ohio, January 8, 1846. 
Arr. VIL.— Observations on the Eocene formation of the United 
States, with descriptions of species of Shells, Sc. occurring im 
it; by T. A. Conrav,—(with two plates. ) 
Since I discovered the Eocene formation in Maryland in 1830, 
my own researches and those of others, have proved its wide ex- 
tension in the southern and southwestern states, and I now pro- 
pose to publish descriptions and illustrations of most of the organic 
remains of that formation in the pages of this Journal. The devel- 
opment of the Eocene is much greater than was supposed, in conse- 
quence of its embracing a white friable limestone, formerly refer- 
red to the upper cretaceous period. In reviewing the organic re- 
mains of that rock, I t resist th i that it is so nearly of 
the same age with the Eocene sands of Alabama, Mississippi, Louisi- 
ana, é&c., that it may not with propriety be referred to an earlier era. 
. The occurrence of what were supposed to be remains of Enalio- 
sauri, now proved by Mr. Owen to be more of a cetaceous char- 
acter ; the genus Plagiostoma, Gryphaa vomer, (Morton, )and one 
or two other secondary forms, led me to believe that the limestone 
in question was a connecting link between the secondary and 
tertiary strata. But I now find the group of fossil genera to 
have so decided an affinity with that of the Eocene period, that 
I confidently class the whole white limestone of the southern 
parts of Alabama and Mississippi with the strata of that era. This 
limestone is extensively developed in Clarke Co., Alabama, where 
Seconp Series, Vol. I, No. 2.—March, 1846. 27 
