210 WAPPINGER LIMESTONES AND ASSOCIATE STRATA. 
complicated stratigraphy of the western portion of 
Dutchess county. Wespent the first and second days 
of October in a visit tou Stissing mountain. Our chief 
object was to find paleontological evidence of the strati- 
graphical horizon of the quartzyte which immediately 
overlies the Archeean gneiss of the mountain. This 
quartzyte has been assigned to Potsdam by Prof. 
Mather (in the N. Y. state survey), Dana, and others, 
but on purely stratigraphical grounds, since fossils have 
never before been found init. In June of 1884, Mr. 8. 
W. Ford and the writer visited the locality between two 
trains. In the limited time at our disposal, we did 
scarcely more than to make ourselves somewhat ac- 
quainted with the topography and the more accessible 
points of observation. The only quartzose rocks which 
we examined, were those of a solid, very white, compact 
quartzyte forming conspicuous ledges on the lower 
slopes of the mountain at the south end, which is the 
only part which we visited. 
On the occasion of the visit made by Mr. Walcott and 
myself, we examined much more carefully the same part 
of the mountain. Leaving the Stissing railway station, 
which is situated on shales of the Hudson river group, 
we followed the road running up the valley along the 
eastern flank of Mt. Stissing; the shales soon gave place 
to acompact bluish limestone, which in turn was fol- 
lowed by ared shale of lively color. Taking the first 
farm-road which, leading west, passed over the southern 
end of the mountain, we crossed another belt of lime- 
stone, which, at a point a little further up the main val- 
ley road, has been quarried and burnt for lime. After 
ascending some distance, we passed from the limestone 
to the quartzose strata which are in turn followed, on 
further ascent, by the underlying gneiss which forms 
the mass of the ridge. 
The compact, white quartzyte in the bold terminal 
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