90 GEOLOGY OF OHIO. 
further north. In a few localities where the Berea sandstone has been 
examined, it contains some pebbles, but these are few in number, and 
generally altogether absent. In the gorge of Tinker’s Creek, at Bedford, 
Cuyahoga county, the lower part of the Berea sandstone, which forms 
the cliffs at the railroad crossing, contains a few pebbles, some of which 
are of large size; but these are not sufficiently abundant to give to any 
portion of the mass the character of a conglomerate. 
The economic value of the Berea grit is very great, as it supplies a 
building stone which is now sent to all parts of the Union, and has 
even been exported to England. This is the “Ohio Stone” of the 
New York market, where, from its homogeneous texture, the facility 
with which it is worked, and its warm, pleasant, buff tint, it is highly 
esteemed. It is equally valued in the cities upon the shores of the 
great lakes, and in all of these it is extensively used for architectural 
purposes. The principal supply of grindstones throughout the Northern 
States is also derived from this group, of which the center of production 
is Berea. 
The fossils of the Berea grit, though nowhere very abundant, are of 
peculiar interest. The massive layers opened in the quarries at Am- 
herst, Berea, Independence, etc., have yielded almost no fossils; but in 
the flagstone of the upper portion there have been found in the quarry 
of Mr. Goodale, at Chagrin Falls, large numbers of fishes of the genus 
Palxoniscus (P. Brainerdi), with bones and plates of other and larger 
fishes which as yet remain undescribed. At Berea the upper layers con- 
tain a largespecies of Lingula (L. Scotica), and spines of Ctenacanthus. But 
the most interesting fossil found in this formation is a plant that covers. 
some of the surfaces of the layers at Bedford, and which I have been 
unable to distinguish from Annularia longifolia of the Coal Measures. 
On Oil Creek, in Pennsylvania, a stratum of sandstone, which appar- 
ently represents the Berea, contains in large numbers the spines and teeth 
of fishes. Of these the most conspicuous are the spines of a species of 
Ctenacanthus (Ct. triangularis), of which more than two dozen were found 
by Mr. Gilbert upon a surface not larger than a square yard. With these 
Spines are numerous teeth of Selachians, representing the genera Orodus, 
Cladodus, Helodus, etc., one of which (Helodus coniculus) is common in 
the Burlington and Keokuk limestones of Illinois. In the aggregate 
we have now seven species of fishes represented in the fossils of the 
Berea grit, all of which are of decidedly Carboniferous type, and, as has 
been said, one or more are such as have been found elsewhere in Lower 
Carboniferous strata. 
3. Bedford Shale—Beneath the Berea grit, in northern Ohio, we find 
