UPPER ORISKANY OF NEW YORK 301 



observable on the bottom of the layer which covers it, and in other parts 

 by a thickness of about 6 inches. . . . The lower part of the sand- 

 stone abounds in fossil shells remarkable for their great size." 



In 1840 Conrad * gave a section of the rocks as observed by him and 

 John Gebhard, junior, the pioneer collector of Schoharie, New York, and 

 places the Oriskany between the " Brown sandstone [Esopus grit] and 

 Blue limestone " (Becraft of the Helderbergian). The fossils character- 

 izing this zone are Atrypa elongata (= Rensselxria ovoides Eaton), Delthyris 

 arenosa (= Spirifer arenosa), and Strophomena unguiformis (= Hipparionyx 

 proximus Vanuxem). 



In 1842 Vanuxem t gave what was known of the Oriskany formation 

 in the third geological district of New York, and illustrated the charac- 

 teristic fossils. These are Spirifer arenosus Conrad, Rensselseria ovoides 

 (Eaton), Eatonia peculiaris (Conrad), and Hipparionyx proximus Van- 

 uxem. He stated that — 



" This sandstone . . . is readily traced from east to west through the dis- 

 trict, by its composition and its numerous characteristic fossils, not so much as to 

 kinds as individual species. Its position is best seen in the first district near 

 Salem ; the Helderberg division, of which it forms a part, being complete. It pro- 

 jects from the side of the Helderberg mountain, forming a terrace resting upon the 

 Catskill shaly limestone [= New Scotland ; the Becraft is here absent]; . . . 

 the sandstone passing under, or covered with the Cauda-galli grit, the latter being 

 a thick abrupt mass. 



" In the third district, its immediate associates cease entirely before reaching the 

 west end of Madison county ; and the sandstone from thence rests upon the Man- 

 lius waterlime group, and is covered by the Onondaga limestone, the three rocks 

 being coassociates to Cayuga lake. It is very variable in thickness, owing prob- 

 ably to the unevenness of the surface upon which it was deposited. 



" With some exceptions, this sandstone consists of a medium sized quartz sand. 

 . . . It is of a light yellow color when pure, as at Oriskany Falls. At other 

 localities the yellow color is often shaded brown, or of some other dark color." 



West of the Hudson river, in eastern New York, the Oriskany — 



"Is well exposed in the hills east and west of Schoharie, various places on the 

 Helderberg in Bern, Knox, and Bethlehem, and occasionally as it ranges south- 

 ward to Esopus falls, beyond which it was not recognized. The Oriskany sand- 

 stone [in this region] is generally a hard silicious grit, which generally approaches 

 chert and hornstone in aspect, and is replete with fossils. In some places it is 

 white ; in others brow r n, red, and black. ... In the first district, it rarely ex- 

 ceeds 2 feet in thickness, and in many places it is not more than 8 inches, and in 

 some places is absent; but it is extensive, strongly marked in its fossil contents, 

 which are of large size, and generally attracts the attention of persons traveling 

 along the roads." j 



* Third Ann. Rept. Pal. Dept., Survey N. Y., 1840, p. 40. 

 fGeol. N. Y., part iii, Survey Third Dist., 1842, pp. 123-127. 

 t Geol. N. Y., part i, Survey First Dist., 1843, pp. 342, 343. 



