﻿NO. 7 



SMITHSONIAN EXPLORATIONS, I926 



41 



favored by geological collectors. The beds exhibited are at the base 

 of a considerable invasion of the Portage during the Upper Devonian 

 and carry a distinct fauna of striking forms. Several other noted 

 localities in central and western New York were also paid brief 

 visits. The most important of these trips, both in purpose and result, 

 was that to examine the Middle and Upper Devonian beds at the 

 celebrated series of sections along i8 Mile Creek and the north and 

 south shores of Lake Erie. In this vicinity the entire sequence of the 

 Hamilton, which in central New York comprises some 400 feet of 



Fig. 47. — Ithaca Falls over Ithaca beds of Portage age. Ithaca, N. Y. 



(Photograph by E. R. Pohl.) 



-« 



ruck and in eastern New York and Pennsylvania is as thick as 3000 

 feet, is represented in less than 90 feet of superimposed beds. The 

 faunal sequence, however, is as well marked, and the zones even more 

 distinct than those of their eastern equivalents, for here the succession 

 lacks many of the invasions that are represented in the more easterly 

 deposits of the same age. This portion of the expedition was under- 

 taken in cooperation with the Department of Geology of the Milwau- 

 kee Public Museum, which institution was represented by Mr. Gil- 

 bert O. Raasch, assistant curator of geology. 



Following the work at 18 Mile Creek, Mr. Pohl proceeded alone 

 to Thedford and Arkona, Ontario, Canada, for the purpose of 



