of the Age of the Red Sandrock Series of Vermont. 371 
of such great importance that its history ought to be correctly 
worked out now while the facts are still ‘fresh in the memory of 
all the parties concerned. 
In order that what follows may be more clearly understood, it 
Seems necessary to premise that the geologists of Vermont have 
always distinguished two great arenaceous formations in their 
country differing from each other in aspect and geographical po 
sition. One of these, the “Granular” Quartz Rock constitutes a 
narrow belt lying along the western base of the Green Moun- 
sion that it was the Potsdam itself.* The Red Sandrock Series 
Hall's paper would lead us to sup that he arrived at th 
Same conclusion fifteen years ago. 
° 
Adams pointed out by Mr. Hitchcock. These do not prove that 
he agreed with Veo. but rather that he was of a con 
Shed. I have however succee i 
and shall describe such portions as cross the Red Sandrock. | By 
Comparing Prof. Hall’s paper it will be seen that he has omitte 
to make any allusion to these portions of the sections, the reason 
being, no doubt, that if he had done so, the reader would arrive 
* See Proe, Am. Philosoph. Soc, vol. ii, p. 8, 1841, and also this Journal 1st ser. 
Vol. alvii, p. 151, where Prof. Rogers's views are given 
