142 
PALAEONTOLOGY OF NEW YORK. 
granular limestone which contains numerous species of Encrinites and a 
few corals and shells. [From these, and from other observations of earlier 
and later date, the limestones of the Falls of the Ohio have been considered 
the equivalent of the Corniferous limestone (— Onondaga and Corniferous 
limestones), and generally of the limestones of the Upper Ilelderberg group 
of New York.] 
These authors recognize the black slate, above the limestone of the Falls, as 
having a thickness of 104 feet. 
At a later period Major Sidney S. Lyon published a table of the “ Strati- 
graphical Arrangement of the Rocks of Kentucky ,” in which he gives the following 
table of the beds at the Falls of the Ohio and vicinity: 
q Black slate [= Genesee slate], u Nucleocrinus bed. 
r Encrinital limestone.* v Turbo bed. 
s Hydraulic limestone. w Coral beds. 
t Spirifer bed. x Catenipora beds [ = Niagara formation]. 
The beds from r to w inclusive have been regarded, I believe, by all 
geologists as the equivalent of the Upper Helderberg limestones of New York; 
and without critical examination of rocks in place, or a careful comparison of 
the fossils contained in the several beds, I have heretofore accepted this 
determination, and aided in the dissemination of this opinion. 
This view seems in fact to have been unavoidable, since the fossils from the 
limestones at the Falls of the Ohio have been collected and widely distributed 
throughout the country without reference to the successive beds of the forma¬ 
tion from which they had been obtained. More recently my attention has 
been called to the vertical distribution of the species in these rocks, and 
during the printing of the earlier pages of this volume, I became doubtful 
of the real identity of the higher beds with the New York limestones; and 
in considering the numerous species of characteristic Hamilton fossils which 
* In this table, the thin-bedded or slaty siliceous limestone, with Chonetes and many other fossils, is not 
distinctly recognized, although it is really an important member. 
