Review of the New York Geological Reports. 53 
berculatus, Acanthaloma, Asaphus pleuroptyx, Asaphus nasutus, 
Dicranurus, Calamopora ( favosites) favosa, Delthyris bilobata, 
D. granulosa, D. macropleura, D. pachyoptera, Orthis, Stro- 
phomena indentata, Atrypa prisca, A. inflata, A. concentrica, Pla- 
tyceras ventricosum, P. Gebhardii, Calceola plicata, Conularia 
quadrisulcata, Tentaculites scalaris. 
Gxrpuarp, jr., has distinguished a limestone resting upon, yet 
distinct from the Catskill shaly limestone, under the name of the 
“upper Pentamerus limestone,” which contains a smooth species 
of Pentamerus, in its general form like P. galeatus ; also several 
forms of Atrypa similar to those which occur in the inferior beds 
of this group. 
Oriskany Sandstone. (No. 7 of the Pennsylvania survey. )— 
Though this formation, in some parts of the first district, is only 
a few inches thick, and never exceeds in any part of the State of 
New York thirty feet, yet in Pennsylvania and Virginia it becomes 
a very conspicuous member of the Appalachian system, attain- 
ing, in the former state, the enormous thickness of seven hun- 
dred feet. In New York the Oriskany sandstone is confined 
chiefly to the middle and southern portion of the state, not ex- 
tending further west than Morganville, Genesee County. 
Its lithological character is, for the most part, a tolerably pure 
siliceous or quartzose sandstone of a white or yellow color. At 
Schoharie and the Helderberg generally, it becomes, however, a 
compact, tough, siliceous limestone. Very frequently it is full of 
cavities, the hollow moulds of shells which chemical agencies 
have removed. It is worthy of note, as Vanuxem remarks, that 
“this sandstone and the calciferous sand rock, including the Pots- 
dam sandstone, are the only two rocks of the third district, ( and we 
presume also in every part of the state over which the New York 
system extends,) which presents unaltered the pure sand of the 
primary region.” 
- From the irregular thickness of the Oriskany sandstone in the 
middle part of the state, and the apparent depressions which it 
fills up on the surface of the Onondaga salt group, where the in- 
tervening strata are absent, it has been suggested by Haxx that 
the more elevated and exposed portions of this underlying forma- 
tion might have been, during the deposition of the siliceous rocks 
under consideration, dry land, or at least was beyond the reach of 
