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 

 Palseoniscus (P. Brainerdi), with bones and plates of other and larger 

 fishes which as yet remain undescribed. At Berea the upper layers con- 

 tain a large species 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 ha6 

 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 



