No. 50.] 
377 
some of its localities, so as to make its recognition difficult. Its cha- 
racteristic fossil is the Pentamerus Knightii, which is usually in great 
abundance, also, an Atrypa, resembling the Wilsoni and the Euom- 
phalus profundus. 
Delihyris shaly limestone. This mass makes its appearance to the 
east like the former, and ends in a like manner, carrying with it the 
Delthyris Macropleura, Strophomena rugosa, Orthis resuprinata, Orthis, 
resembling the Concentrica Delthyris pachyoptera. The Delthyris bi- 
lobata, which is peculiar to this rock, I have not yet seen in the third 
district. The Platyceras ventricosum is an abundant and a characte- 
ristic fossil of this rock. 
Scutella limestone. This is likewise a rock of the first district, but 
its fossil being more persistent than those of the two former rocks, it 
is readily traced to Oriskany falls, the ridge to the east of Minsville 
and Fosters' mill, on Oneida creek. The peculiar fossil from whence 
its present name is derived, I have not observed in the third district, 
but all others that are common to it and give to its character there, exist 
in the 3d district ; such as the Atrypa, resembling the hastata, stro- 
phomena tuberulifera, Apiocrinites, Asaphus micrurus, &c. &:c. 
Oriskany Sandstone, exists, with interruptions, through the district. 
At Oriskany-falls, it reposes upon the last named sandstone ; but from 
Madison county, west, in consequence of the absence of all the inter- 
mediate masses, it lies upon the Manlius water lime group. This rock in 
its lower part abounds in fossils, and of a large size, showing that at 
that period the circumstances were highly favorable for the develop- 
ment of this kind of animal life, among them we find the Atrypa elonga, 
Delthyris arenosa. This rock is the fourth position of iron ore, but not 
yet found of a quality suitable for smelting. 
Fucoides Cauda-Galli. This series so extraordinary for the peculiar 
fossil which it contains and from whence its name is derived, is also a 
rock of the first district. It continues through Otsego and Herkimer 
counties, but further west I have not yet seen it. It is an argillaceous 
mass in places somewhat sandy, of a black or dark green, which be- 
comes lighter, and by long weathering blanches. It readily strikes 
the eye by its contrast with the other rocks and by the peculiar markings 
[Assembly, No. 50.] 
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