On the Age of the Sandstones of the Newark Group. 363 



kel of the species C. macrurus of "Virginia are given in the above- 

 mentioned paper of Sir Charles Lyell. 



It has been seen that Mr. J. H. Redfield considers the other 

 fishes of the Connecticut river and New Jersey rocks as more 

 heterocercai in degree than the Catopterus. In some of the 

 species, however, this difference seems less obvious after a close 

 examination of the structure, than it appears at first view. One 

 or two of the species in my possession I think are even more 

 nearly homocercal than the Virginia fish. 



I desire to add, that two of the Lepidoti from the table land 

 of India of which figures are given in the Jour, of the Geol. 

 Society, show very strong resemblances to two or three of my 

 fishes from the sandstone of Connecticut river at Sunderland, to 

 one of which I had proposed the name Ischypterus Marshii. Is 

 it not probable that the vast extent of sandstone and trap in 

 that distant region, is of like age with our Newark group ? 



Already I have ventured to state verbally to the Association, 

 that in the valuable collection of fossils from the coal-field of 

 Deep River in North Carolina, now exhibited by Prof. Emmons, 

 I have recognized several well characterized fragments of the 

 genus Catopterus. A close comparison of these with specimens 

 in my cabinet may perhaps show a difference of species. But 

 my present impression is that of identity with one of the New 

 Jersey species. 



It would be premature to conjecture how far the new fossils 

 of Prof. Emmons may affect the question of the relative age of 

 these rocks. But when we consider that these fishes evidently 

 belong to fresh water or estuary deposits, as is shown by the 

 entire absence of any remains of large marine fishes, by an 

 almost equal absence of shells, and by the numerous fossilized 

 fragments of vegetation with which the fishes are associated, the 

 chronological evidence afforded by their characteristic organiza- 

 tion would seem to be more determinate than that of saurians, 

 plants, or marine fishes, whose general habitat and power of dis- 

 tribution, enable them to occupy a greater range in the geologi- 

 cal series. 



P. S. It is proper to add, that having now compared the re- 

 mains of Catopterus of Prof. Emmons's collection with my own 

 specimens of the genus, I find them scarcely distinguishable 

 from most of those of the New Jersey and Connecticut rocks. 

 Indeed they appear to be identical with 0. gracilis. The chief 

 differences appear in the larger size of most of the Carolina 

 specimens which may be due to conditions more favorable to 

 their growth, and in the less flattened condition of the basal por- 

 tion of the strong and elongate front ray of the pectoral fin, — 

 owing, probably, to a nearly equal pressure on all sides, in the 

 carbonaceous paste" or sediment in which they were fossilized, 



New York, Sept. 12th, 1856. 



