A NEW EURYPTERID FAUNA FROM THE BASE OF THE 

 SALINA OF WESTERN NEW YORK 1 



BY CLIFTON J. SARLE 



With 21 plates 



INTRODUCTION 



In western New York the outcrops of the Salina strata occur 

 in a belt of country averaging 10 miles in breadth, parallel to 

 the southern shore of Lake Ontario, and its northern limit dis- 

 tant thence about 15 miles. On the .Rochester meridian the for- 

 mation is 600 or 700 feet thick, and, in the lower portion, com- 

 prises variously colored shales or marlites, interspersed with some 

 thin layers of dolomite, while in the upper portion are salt and 

 gypsum deposits with some beds of waterlime and limestone. 

 The exposures of the formation in this part of the State are few, 

 owing to the very destructible nature of the rock and to a 

 heavy covering of drift. No sedimentary strata in the State 

 have been considered more barren of fossils. Resting on the 

 Lockport dolomite, which is everywhere replete with fossils, 

 and underlying the Bertie waterlime, which at many locali- 

 ties carries a rich assemblage of eurypterid remains in the thin 

 layers at the top, it has formed a conspicuous break in the 

 paleontologic record. 



It is therefore a matter of considerable interest to announce 

 a rich eurypterid fauna, discovered by the writer in 1898, in the 

 basal layers of the Salina formation, in Monroe county. 



This fauna, though separated from that above by nearly the 

 whole thickness of the Salina, is its counterpart in many 

 respects but perhaps more primitive in its characteristics. The 

 discovery thus affords additional ground in support of the com- 

 prehension within the Salina of all beds included between these 

 faunas. Formerly this association was based entirely on 

 stratigraphic succession and a supposed similarity of physical 

 conditions, from which it was assumed that a similarity of life 

 must be found. 



It is safe to state that this is the earliest fauna yet known 

 to which the name " eurypterid fauna " can be properly ap- 



1 Since this paper was put in type it has been accepted by the faculty of the 

 University of Rochester as a thesis for the degree of master of science. 



