PREFACE 



During the prosecution of the study herewith given of a fauna 

 essentially new to the New York series of geologic formations, I have 

 been under special obligation to Professor Albert L. Arey, of Brooklyn, 

 the first to discover and record the presence of a Guelph fauna at 

 Rochester, for the use of his collections, of which many specimens are 

 here figured. In this place, also, I desire to make acknowledgment for 

 courtesies received from Colonel C. C. Grant of Hamilton Ont. This 

 work has, further, been essentially aided by the fine collections from the 

 tough dolomites at Shelby, made by D. D. Luther, who has also contributed 



important stratigraphic details. 



JOHN M. CLARKE 



State Paleontologist 





