FOSSILS OF THE NIAGARA GROUP. 121 



FOSSILS OF THE NIAGARA GROUP. 



The organic remains of the Niagara group of Ohio have a much 

 greater resemblance to those of the same formation in Illinois, Wiscon- 

 sin, and Iowa, than to those of the more eastern extension of the forma- 

 tion in New York. The greater similarity of condition and composition 

 between the Ohio beds and those of the western localities would at once 

 lead one to suppose this would be the case ; the formation in the two re- 

 gions corresponding in lithological characters, while they are quite dis- 

 similar to the more fossiliferous shaly beds of New York. So far as yet 

 known, the fossil remains appear to be much less numerous in Ohio than 

 westward, but the localities have, as yet, been but imperfectly examined, 

 and in all probability the number of species will be found to be much 

 greater when the examinations shall have been as complete as they have 

 been in many of the more western localities. One of the noticeable fea- 

 tures presented, in looking over a collection of the fossils of the Ohio rocks 

 of this group, is the scarcity of Brachiopodous shells, as compared with 

 collections from New York ; and more especially the sparse occurrence 

 of the genus Spirifera, which in both the New York and western localities 

 is represented by several species. Another peculiar feature is the small 

 number of Crinoidal remains, and especially those of the peculiar group 

 of Cystideans, which is so abundantly represented in the Wisconsin re- 

 gion. Of this latter group there have been but few species recognized, 

 one of which, Gomphocystites glans, has been recognized in several indi- 

 viduals ; and another, resembling Holocystites Winchelli, in two or more 

 specimens, and a few individuals of JT. alternata. Besides these, there 

 is known a single impression of a Cystidean, apparently belonging to 

 the genus Callocysiites, and closely resembling if not identical with 0. 

 Jewetti. Heretofore this genus has been recognized only in New York. 



The class Cephalopoda is rej^resented by several new forms, and by some 

 of those which have been described from other localities. The species 

 are much more numerous than in New York, and, judging from the num- 

 ber already collected, will, when the localities are more completely ex- 

 amined, and the collections as carefully made, compare very favorably 

 with those from any of the western localities. The small number of 



