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[Assembly 
of its fossil, so strongly resembling the plumage of the male of the 
barnyard fowl, 
Schoharie layers. These layers I have not yet seen in the district, 
but I have found detached pieces of limestone which evidently were 
severed from them. These are the layers so abundant in fossils, and 
have furnished such numbers to the collectors of Schoharie. Among 
its fossils are Phragmoceras arenatum, Lituites bidulpliii, Spirorbis 
tenuis, Calymene Rowii, (fee. 
Onondaga limestone. This is the limestone or marble so well known 
and so extensively wrought, from Auburn to Cherry- Valley. West of 
Oneida county it is the stone which is used for all the exposed masonry 
of the enlarged Erie canal. 
In the bottom layer of this rock, pebbles of black sandstone are often 
seen, having been derived from the breaking up of the Oriskany sand- 
stone, These pebbles were concretions in the sandstone, and they 
may be seen in situ on the farm of Mr, Eastman, on the road from 
Waterville to Paris Hill, 
The Onondaga limestone abounds in Testaceous fossils, the most 
characteristic ones have not yet been named. It contains a new spe- 
cies of Pentamerus, which is met with in all its localities that I have 
examined. The atrypa Nasuta is confined to this rock. 
" Corniferous limerock^^ of Prof. Eaton. The lower part of this 
mass often presents a limestone more or less mixed with aigillaceous 
matter, forming a shaly rock, whilst the upper with few or no excep- 
tions exhibits from one to even ten parallel ranges of nodular flint, 
whence its name. This occurrence of flint is not peculiar to this rock, 
for it occurs in the Onondaga, the pentamerus and other limestone 
rocks but less frequently. It has however two fossils by which it may 
always be known, the Platyceros dumoso, and the Cyrtoceras , 
many specimens of the latter may be seen in the limestone flags, with 
which parts of the city of Utica are paved. 
Seneca limestone. This is the last of the immense series of lime- 
stone and other rocks, which form the northern termination of the great 
east and west elevation, which extends through the State. All of them 
from the Manlius waterlime group, are only found on the south side of 
