Limestone Belts of Westchester County, N. Y. 373 
money, 
that of the Northern. My study of the position of the beds has 
not resulted in the discovery of any want of conformity between 
the rocks of different areas except such as can be traced to 
contortion. The east-and-west and northeast trends appear 
therefore to have been results of one and the same system of 
disturbance. 
This argument with reference to the relation of the rocks to 
those of the Green Mountain system cannot be regarded as 
wholly satisfactory without a fuller presentation of the facts 
from the adjoining portions of Connecticut, and this will be 
given in another number of this Journal. 
3. The limestone and associated rocks are younger than the 
Archean of the Highlands. 
The region affords three classes of decisive facts. 
(1.) The rock adjoining the Archzan in the southern part of 
Canopus Hollow near Annsville is a bluish slightly crystalline 
limestone, so slightly that it might for all this contain fossils. 
This nearly uncrystalline condition characterizes the limestone 
for a mile up the valley though not in so extreme a pi 
and beyond this it has nowhere the coarseness of the lime- 
stones to the : ee 5 
(2.) The limestone area is bordered on its west side, opposite 
