BERNARDSTON SERIES OF UPPER DEVONIAN. 255 



but not seen in contact, is noted. The complex foldings of tlie arfiillitt- 

 are described and figured. (G, pp. 289, 295.) Concludes that the encrinal 

 limestone is newer than the argillaceous slate. 



1841. Doubts are expressed as to the encrinal character (tf the fossils. 

 The relations of the argillite, limestone, and quartzite described as before. 

 (7, pp. 54, 556, 560.) 



1851. Because of the discovery of an upper stratum of slate (the uj)per 

 schist described below) beneath which the limestone passes, it is decided 

 that the whole of the argillite together with all the series to the top of 

 the upper schist of the section on page 258 is Devonian, in jiccordance 

 with the determination of the crinoids by Prof. James Hall, who thouglit 

 them to be of the age of the Onondaga limestone. (10, p. 2!)S.) 



1858. Bernardston and West Northfield are divided aliout efjually by 

 a north-south line between argillaceous slate on the west and hornblende- 

 schist on the east, with the number for mica-slate entered on the area 

 of the latter, but not subdivided from the rest. Limestone and iron ore 

 marked. (H.) 



1861. While the preceding hi.story has dealt entirely with the work of 

 President E. Hitchcock, I understand, though it is not distinctly stated in the 

 chapter in question, that the report of the Vermont survey was based upon 

 the studies of Prof C. H. Hitchcock, and I have so indicated above 



Under the heading "Upper Helderberg Limestone" is given the best 

 section vet published of the rocks in question, containing ever}' bed of 

 importance except one, and indeed one bed, D, a clav-slate immediately 

 above the limestone, which does not exist: All the beds from the argillite 

 up are made conformable, but no other indication is given in the chapter as 

 to how much of the series is assigned to the age indicated in the heading. 

 The upper quartzite (that is, the quartzite east of the limestone on the 

 Williams farm) is suspected to rest unconformably upon the argillite in Ver- 

 non, the intervening members being absent, and on page 598 of Vol. II this 

 quartz rock, with the gneiss into which it grades, is assigned to the Devo- 

 nian age, from its identity with the upper quartzite of the Williams farm sec- 

 tion. Attention is called to the fact that an upper schist resting upon the 

 quartzite — it is described as a "distinct clay-slate, thicker-bedded and harder 

 than most clay-slates" — is not elsewhere seen resting iipon the (quartzite. 

 This I have not found to be tnie. (12, Vol. I, p. 447; Vol. II, p. 5!)8.) 



