A List of the Fossils Occurring in the Oriskany Sandstone of 

 Maryland, New York and Ontario. 



Prepared by Mr. Charles Sehuchert, from an examination and arrangement of my own 

 collections and the published descriptions of species from this Geological horizon. 



In connection with, my work upon the Brachiopoda during the 

 past year it became necessary for me to overhaul and arrange an 

 extensive store of Palaeozoic fossils which had accumulated on 

 my hands from purchase and exchange during the past fourteen 

 years. Among these were large collections from the Oriskany 

 Sandstone of Maryland and of Ontario, Canada ; these being the 

 two extreme points from which I have obtained any considerable 

 number of fossils from this formation. 



The relations of the Oriskany Sandstone to the Silurian below 

 and the recognized Devonian above have been subject to discus- 

 sion from time to time during the past years. 



In Volume III, Palaeontology of New York, I had already 

 introduced the subject of the geological range of certain species 

 of the Oriskany Sandstone and the relations of this formation to 

 the Lower Helderberg Eocks of Silurian age and those of the 

 succeeding Devonian period. 



At that time (1859) our collections had not reached the extent 

 they have since attained, and therefore our comparisons and 

 inferences were very imperfect and incomplete. 



I have long intended to prepare and present to the public such 

 a catalogue as the following, but my duties, and the pressure of 

 other and more immediately important work upon my assistants, 

 has always prevented the accomplishment of this object up to the 

 present time. The arrangement of this list will show the geologi- 

 cal range of each species thus far know in the Oriskany Sand- 

 stone, and the legitimate conclusions can be readily inferred.* 



*The varying physical conditions which have prevailed during the deposition of this 

 sandstone over the large area indicated by this extensive outcrop are worthy of more 

 careful consideration that my time and the present circumstances will permit 



