ERIE DIVISION. 
323 
were first observed by Prof. Vanuxem, who found their stratum about six inches thick. Se¬ 
veral localities were observed where many species of fine shells may be obtained, in the bluish 
and brownish gritty shales on the road from North-Blenheim to Gilboa. 
The joints of vertical planes intersecting the rocks are remarkably well characterized in 
the Hamilton group, near North-Blenheim post-office. 
Limestone containing fossil shells is said to occur on the summit of the isolated mountain 
called the Roman Nose, in Schoharie county. This position would be in or above the Hamil¬ 
ton group, and at or near the position of the Tully limestone. I did not examine the locality. 
Septaria occur abundantly in the Marcellus shales in Schoharie county. Mr. J. G. Geb- 
hard junior, found them near Middleburgh and Mann’s valley. They are of various sizes and 
shapes, generally of a flattened ovoidal form, from a few inches to three or four feet in diame¬ 
ter. Pyrites in brilliant drusy crystals, and a little pyritous copper were observed in the septa 
of some of those near Mann’s valley and Cobleskill. The slate is very black, and overlies 
the limestone,* and excavations in search of coal have been made near Cobleskill, Punch 
brook and Middleburgh. Carbonaceous matter is diffused in minute particles, and interlami- 
nated in extremely thin films ; but it is superfluous to add that there is no hope of finding coal 
in it. 
Various fossil remains have been found by Mr. J. G. Gebhard junior, in this black slate, 
which will be figured and described in the palaeontological part of this work. 
The Catskill and Erie divisions form the high mountain region of Greene, Ulster, Sullivan, 
Delaware and Schoharie counties. The streams flow in deep valleys, which seem to have been 
formed by erosive action; since the strata, in most instances, correspond on the opposite sides 
of the valleys. There are some exceptions where* there are indications of great fractures and 
rents of the strata, which traverse the country for many miles, and give direction to the 
streams. The soils on this formation are generally good ; but as the country is very heavily 
timbered, much time, labor and expense, are required to bring them into use. 
Near Cobleskill village, the black slate containing septaria is overlaid also by a bed of limestone, but this may belong to the 
Helderberg division. The rock was not traced to find its connection with other rocks. 
41* 
