1889. ] NEW YORK ACADEMY OF SCIENCES. 4% 
water-colors ; a man of genial and quiet manners, he made hosts 
of friends. 
Your committee, in conclusion, recommend the adoption of 
the following:— 
Whereas, It has pleased an all-wise Providence to remove from 
our midst our late friend and fellow-member Benjamin B. 
Chamberlin; therefore, 
Resolved, That we tender his surviving relatives our heartfelt 
sympathy in their bereavement. 
Resolved, That in his death we recognize the loss to science, 
and to ourselves, of an earnest friend and fellow-worker, whose 
place in the field of local mineralogy it will be hard to fill. 
Resolved, That a copy of this memorial and accompanying 
resolutions, properly signed by the officers of the Academy of 
Sciences, be forwarded to the relatives of the deceased and pub- 
lished in the Transactions of the Academy. 
W.H. J. SIEBERG, 
DANIEL S. MARTIN, - Committee. 
GrorGE F. Kunz, 
The resolutions were unanimously adopted, and their trans- 
mission and publication ordered. 
Mr.:THeoporRE D. Ranp, of the Academy of Natural 
Sciences of Philadelphia, then presented the paper of the even- 
ing, entitled 
A DISCUSSION ON THE ROCKS OF PENNSYLVANIA AND NEW 
YORK. 
Having given some study to the geology of the region lying 
west of Philadelphia, I have come before you to state some facts 
in relation to it, and to compare views with your members, in 
hope that we may thus get new light on both regions; for there 
can be no question that the same group of rocks underlies both 
the cities of New York and Philadelphia, as well as the city of 
Baltimore. While there has been much discussion as to the age 
of these rocks, no theory has been largely accepted. 
In one respect Philadelphia is better situated for this study 
than New York, as we have near us certain rocks, the age of 
which is known almost without doubt, though on the other 
hand the Philadelphia rocks are much more decomposed and 
covered. 
Upon the wall I have placed a section of the rocks from the Trias- 
sic of Montgomery Co., Pa., south-eastward to the Cretaceous of 
New Jersey “(see Plate), and also an excellent map by Prof. Mar- 
tin, containing his geological map of New York and vicinity, ex- 
