THE L 0 UIS VILLE LIMESTONES. 1 4 3 
they contain, I became satisfied that there was room for farther inquiry and 
comparison. 
In the month of August of the present year (1877), during a low stage of 
the water in the river, I had an opportunity of examining the waterlime 
and superincumbent beds, as well as the coral-bearing beds beneath. 
A considerable portion of the waterlime beds consists of an argillaceo- 
magnesian limestone, destitute of organic remains. The upper part con¬ 
tains many specimens of Spirifera euruteines, and the thinly-bedded, slaty 
and siliceous strata above it are charged with numerous fossil species, the 
most abundant of which is the Chonetes Yandellana; but many other known 
forms occur, and the entire facies, when critically viewed, presents the general 
aspect of the fauna of the Hamilton group. The encrinital bed above these 
thin layers contains numerous Crinoidea, all of which are congeneric with 
Hamilton forms, and many of the species are identical with those known in 
that horizon in the State of New York. 
The following tabulated list of species from the Devonian limestones at the 
Falls of the Ohio, though incomplete, will serve for a comparison with the 
Upper Helderberg and Hamilton groups of New York. The species indicated 
in the first column are known species of the Upper Helderberg limestones of 
New York,* and occur at the Falls of the Ohio in beds t, u, v and w of Major 
Lyon’s series (p. 142). All the species which pass upward into the succeeding 
hydraulic and encrinital limestones are likewise known to pass from the 
limestones below into the Hamilton group in the State of New York. A 
considerable number of species occur in the Louisville upper limestones which 
are not known in the Hamilton group of New York; but these are largely 
among the Crinoidea, where there has been no opportunity for a critical com¬ 
parison of specimens. The corals, with a single exception, are omitted from 
the list, since they are almost in all respects identical with those of the Upper 
Helderberg limestone of New York, and their mention is quite unnecessary 
for the present purpose. 
* Pleurotomaria imitator, Turbo Shumardii and Dalmanites Calypso have not yet been observed in this 
formation in the State of New York. 
