iter Geology and Paleontology. 275 
GEOLOGY AND PALEONTOLOGY. 
The Cuyahoga Shales.—C. L. Herrick has published a paper 
in which he summarizes his studies of the Cuyahoga shale and the Ohio 
Waverly as follows: 
1. The Berea grit is the natural floor of the series, the Bedford 
shale having its faunal relations decidedly with the shales of the Devo- 
nian below. 
ža ihe Bediord forms a striking exemplification of the doctrine 
of colonies, and that portion lying to the sogthwest, beyond the 
western limits of the Erie, retained a fauna derive from the Hamilton 
long after this fauna had perished to the eastward. 
3. The Cuyahoga shales (including the whole series above the 
Berea so far as present in the Cuyahoga valley) is divisible into three 
minor sections, the uppermost of which is characterized by a vast 
abundance of fossils, which are specially well preserved in calcareous or 
ferruginous concretions, and is a constant and almost unvarying horizon, 
extending from Lake Erie to the Ohio River. The Cuyahoga proper 
is never more than 200 feet thick, and forms a transition zone, with a 
‘prevailing Devonian habitus. 
4. The upper portion of the Waverly is quite distinct from what 
precedes in fauna, and contains an undoubtedly Lower Carboniferous 
assemblage. 
5- None of the larger divisions of the Carboniferous of the west, 
are entirely unrepresented in Ohio. 
6. The transition is nevertheless so gradual that we have an instruc- 
tive illustration of the evolution of one age from the preceding, with 
neither catastrophy nor annihilation. 
7- There is an opportunity to trace the ERPE variations in a 
species as distributed over a great area, and to obsẹrve the evolution of 
new types therefrom. 
8. The entire thickness of the Waverly is not far from 700 feet, 
though the highest consecutive section measures only 670 feet. 
9. The Cuyahoga fauna bears an unmistakable resemblance to the 
so-called Subcarboniferous of Belgium, especially that ot Etage I., 
the limestone of Fornari 
The Pilot Knob of Texas.—Robt. T. Hill has made a study of 
Pilot Knob in the vicinity of Austin, Texas, and has reached the fol- 
lowing conclusions; 
“From its structure it is shown that Pilot Knob is the neck of an 
