480 NEW YORK STATE MUSEUM 
A? About 15 feet of light gray calcareous sand- 
stone shown in the wall of the quarry which separates 
into three beds; the lower one 7 feet, 6 inches in thick- 
ness, the middle one 4 feet and the top one 3 feet. 
There are masses of calcite and flint in the rock, also 
quartz crystals. The wall of this quarry is well shown 
in the accompanying picture. 
A’ Calciferous ledges partly covered to the edge of 
the woods. 
Glens Falls sections 
Feet 
15709 
30=85 
Along the banks of the Hudson river at Glens Falls are ex- 
cellent exposures of the Trenton limestone, which has been ex- 
tensively quarried. The Finch and Pruyn quarry on the northern 
bank of the river affords an excellent opportunity to study the 
different zones of this limestone as may be seen in the following 
section: 
54B1.A calcareous sandstone 2 feet of which was 
above the river level at the locality measured. This 
has usually been referred to the Calciferous formation! 
but Mr Walcott has stated that in the vicinity of 
Glens Falls he is “inclined to think that it is impos- 
sible to recognize, by lithologic characters, the Cal- 
ciferous formation as distinct from the Chazy lime- 
stone horizon; and at Glens Falls Maclurea. 
magna [a Chazy species] and great numbers of 
an Ophileta likeO. compacta [a Calciferous 
species] are found in the same stratum of rock but a 
little distance beneath the Trenton limestone, an oc- 
currence that renders it very difficult to state what is 
to be assigned to the Calciferous horizon in this 
region.” 
B? At the base of this zone is a shaly parting, then 
a limestone in which is a large specimen of Colum- 
naria alveolata Goldf. and above is thin to 
thick bedded dark blue lumpy limestone, the thicker 
layers of which contain fossils. The Colum- 
naria in this zone is apparently at the same horizon 
as that noted in Darton’s section (p. 428). 
Feet 
25 
2— 2 
$274 
43th annual report N. Y. state ae p. 424. See base of section on p. 428. 
. 22. 
2U. S. geological survey, bul. 30, 1886, 
