J. D. Dana—Hudson River Age of the Taconic Schists. 875 
a round nebulosity, between 30” and 40” in diameter, without 
definite nucleus, though much brighter in the center. Before 
the. new moon a faint tail was visible, about one-half degree in 
length. It appeared like a thin streamer, much narrower than 
the head of the comet, perfectly straight, and directed from the 
sun. 
Princeton, N. J., April 5, 1879. 
Art. XLVL—On the Hudson River Age of the Taconic Schists, 
and on the Dependent Relations of the Dutchess eres 8 and 
Western Connecticut Limestone belts; by JAMES D. D 
THE paper by the writer on the Relations of the Geology of 
Vermont to that of Berkshire, in volume xiv of this Journal 
hans closed (on p. 264) with the following paragrap 
_ magnitude of the results are strong evidence that the 
so- called limestone-area is really but a small part of a larger 
region of cotemporaneous disturbance and uplift. The true 
breadth of the area, as well as length—-whether it reached to 
the ibe oo Big: on the east and to the Hudson River 
rocks of Western en tierebanits on which Percival’s 
Report contains little, since he aimed chiefly to deseribe pi 
kinds of rocks and their geographical distribution, and did n 
note where, in any case, sn of stratification and of lithological 
distribution were, as is often too not codrdinated.* I have 
al was a very exact man in all his work. He made great numbers 
persistent Tithological characters. It is due to Percival to say that his theory did 
not lead him to the slightest perversion of the stratigraphic or other facts before 
pie pag art neon ppg seg a their bearings; and had the State 
of Connecticut been mo gene ce of time for the com- 
pew of the survey, and of m Leica nade oe yee of his notes, there would 
been little left for later geologi 
oe sg ene No. 101.—May, 1879, 
