Animals Hefore Man 



American relative, Botliriolepis, are, however, 

 the best known of these early species, because 

 the bony armor was more complete in these 

 than in the others, and while usually so broken 

 and distorted that its shape is unrecognizable, 

 now and then a well-preserved example is 

 found. In the Potsdam (Devonian) sandstone 

 of Tioga County, Pa., is a layer containing 

 thousands of plates of Bothriolepis, but so 

 broken and so mixed together by their knead- 

 ing at the hands of the waves that as specimens 

 they are useless ; they merely tell of the former 

 abundance of these animals, and of their whole- 

 sale destruction. 



In the Corniferous Limestone a few miles 

 north of Columbus, Ohio, is a bone bed perhaps 

 even more remarkable than this. 'Though only 

 from 2 to 4 inches thick, it covers an area of 

 many square miles, and is composed almost 

 entirely of broken spines, fragmentary plates, 

 and teeth of fishes, representing, says Dr. New- 

 berry, millions upon millions of individuals. 

 And near North Vernon, Ind., is another simi- 

 lar deposit, formed, too, of the ruins of millions 



92 



