Proceedings of the Society. 73 



cystidean belonging to a new genus, that he proposed to call Hyhocys- 

 tites, and a Colpoceras, which he had collected in these rocks. 



Mr. S. A. Miller made some remarks upon the Trenton age of the 

 rocks described, as evidenced by the fossils collected in them. The cri- 

 noids andcystideans exhibited are the same that are found in the Tren- 

 ton Group, at Ottawa, Canada. The brachiopods are characteristic of 

 the Trenton Group in New Yurk and Southeastern Missouri, and these 

 cephalopod of the Black River Group of New York. None of these 

 species have ever been found in rocks higher than the Trenton Group, 

 and some of the genera are also confined to the rocks of this age, not- 

 withstanding the great geographical distribution and their well known 

 appearance at points more than one thousand miles apart. He 

 thought from the estimate of the thickness of the Trenton in the 

 limited area, mentioned by Prof Wetherb3^ and from other informa- 

 tion respecting this group of rocks in Kentucky, that the total thick- 

 ness of the group in that state may be found to be 800 or 1,000 feet. 

 That the top of the Trenton Group appears in the bed of the Ohio 

 river, opposite that part of Cincinnati called Fulton, that it is here 

 succeeded by rocks of the age of the Utica Slate of New York, about 

 which there can be no doubt, in the mind of any one conversant with 

 the fossils, though, on account of the calcareous character of the strata 

 and their graduation into the well known rocks of the Hudson River 

 Group, which constitute the hills back of the city of Cincinnati, the 

 line of separation between the Utica Slate and the Hudson River 

 Group is not so well determined. 



Mr. Alex. McAvoy was elected to regular membership. 



Donations were received, as follows: 



From Ed. R. Quick, several specimens of fish, crustaceans and rep- 

 tiles collected in White river, near Brookville, Indiana. 



From Geo. L. Murdock, of San Francisco, California, a specimen of 

 Hippocampus. 



From Prof. A. G. Wetherby, Leperditia fabulites, from the Trenton 

 Group at High Bridge, Kentuck3\ 



From a member of the Society, a very large specimen of Placenti- 

 ceras placenta., from the Tombigbee Sand of Alabama. 



