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the fauna so gradual as to be perceptible only upon very careful 

 observation. It is shown that the more or less barren Sherburne sand- 

 stones separate the faunas of the Hamilton and Ithaca groups, and 

 represents the beds which have been designated as Lower Portage in 

 western New York. The correctness of this correlation is shown by 

 the discovery of the typical Tully limestone species Hypothyris venus- 

 tula = H. cuboides just below the Sherburne sandstone near Nobles- 

 ville in Otsego county very much farther east than this species has been 

 previously found. 



The results of Prosser's investigation necessitate the changing of 

 the upper boundary of the Hamilton formations from five to fifteen 

 miles further south than the similar line on the geologic map recently 

 published by the Geological Survey of New York. 



3. The Stratigraphic Position of the Portage Sandstones in the Naples 

 Valley and the Adjoining Region. By D. D. Luther. Pp. 223-236, 

 plates I— II and one map. The purpose of the investigation described 

 in this paper was to ascertain the dividing line between the Portage 

 and the overlying Chemung group in western New York. The sec- 

 tion of the Portage series in the Naples Valley is described in detail, 

 and the Portage sandstone which marks the upper limits of the 

 series is shown to lie at an elevation of 600 feet above the base of 

 the series. With the data derived from the study of the Naples sec- 

 tion the Portage sandstone is traced eastward to Seneca Lake and 

 westward to Lake Erie. 



4. The Economic Geology of Onondaga County, New York. By 

 D. D. Luther. Pp. 237-303, plates I-XXI and one map. In this 

 paper the rock formations of the county, from the Clinton group 

 below to the Portage shales above, are discussed in their proper order 

 of succession. While attention is given to the geologic character 

 and distribution of each formation, the especial value of the report 

 consists in its exhaustive treatment of the most important economic 

 products of the county, viz., salt, soda-ash. gypsum, hydraulic cement 

 and quarry stone. 



5. 77/i? Structural and Economic Geology of Erie County. By I. 

 P. Bishop. Pp. 305-392, plates I-XVI, figures 1-6. This paper 

 opens with a brief account of the topography of the region, after which 

 the stratigraphic succession is discussed at considerable length. The 

 formations present extend from the Salina group at the bottom to the 

 Portage group at the top. The superficial deposits are discussed under 



