LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 443 
on arenaceous rock (Calciferous) which forms the floor of the 
quarry at that point. Apparently the Birdseye limestone has thinned 
out entirely in a distance of two rods. In the western part of the 
quarry the Calciferous is not reached and the lowest layers exposed 
have the characters of Birdseye though there is here no sharp line 
between the Birdseye and Black river limestones. In the central 
part of the quarry there are apparently from 7 to 9g feet 
through which the Columnaria alveolata ranges. The 
rock at this point is compact and thick bedded. In the western part 
of the quarry the same layers are coarser grained and even more 
massive. In fact they resemble the lower massive member of the 
Trenton substage in lithologic characters, but their fauna as will be 
seen from the above list is characteristically Black river. No. 8 as 
seen in the western part of the quarry presents most peculiar 
characters. Portions of it are almost entirely made up of fragments 
and pebbles of brownish arenaceous rock quite similar to the Cal- 
ciferous sandrock. The matrix is somewhat crystalline and contains 
a few small specimens of Columnaria alveolata which 
from their general appearance and association may be regarded as 
derived from the subjacent Black river beds in a manner similar to 
that in which the arenaceous pebbles were derived from the Cal- 
ciferous sandrock. In some parts of the quarry, specially the 
southern part, the Black river limestone contains an abundance of 
iron pyrites and in some cases pockets lined with crystals of calcite. 
The upper surface of the rock at this point is striated, the striae 
running N 85° W. The dip of the strata in this quarry is about 
24° S, 20° W. Vanuxem mentions pebbles similar to the ones 
occurring in this quarry, at Tribeshill and about Amsterdam.! 
The Trenton limestones are exposed at several points between 
Quarry hill and Mannys Corners, and both north and south of the 
highway one half mile east of Mannys Corners are small quarries in 
the Black river and Birdseye beds. In the exposure south of the 
highway are 8 feet of dark lumpy limestone and 1 foot of 
compact fine grained limestone at the base. North of the highway 
the Birdseye limestone is exposed and contains excellent examples 
of Phytopsis tubulosa_ Hall, with the surface reticula- 
tion mentioned by Emmons (pt 2, p. IIo). 
Between Quarry hill and Van Epp’s hill (the high hill just north- 
1Geology of New York, pt 3, p. 44. 
