386 TALCOSE CONGLOMERATES. 



stratigraphy previously adopted" by me, shall prevent me from meeting the question fairly and frankly. 

 I have not sought a controversy on this point, but it is quite time that we should all agree that there is 

 something of high interest and importance to be determined in regard to the limitation of the successive 

 fauna; of our older palaeozoic rocks. I am very truly yours, &c., 



JAMES HALL. 

 Albany, N. Y., January 23, 1861. 



[NOTE BY E. H., SENIOR.] 



July 18, 1861. Still more recently, other able and voluminous papers have appeared on the subject 

 discussed above. In the Canadian Naturalist and Geologist for June, is an elaborate paper, by Sir William 

 Logan, on the Quebec group and the upper copper-bearing rocks of Lake Superior: In the latest Bulle- 

 tin of the Geological Society of France, we have an article of more than 100 pages, entitled, Documents 

 anciens et noveaux, sur le Fauna primordiale et le Systeme Taconique en Amerique ; by Barrande. 



We have neither time nor space to give even a synopsis of these papers. They contain essentially the 

 same views as are expressed above by these distinguished savans. We feel, however, somewhat in doubt 

 whether we understand Barrande in his concluding remarks. After quoting from Sir W. Logan's paper given 

 above, he says, rf Terms so clear and positive need no commentary. It is a formal recognition, by Sir W. 

 Logan, of the Taconic System at the base of the Lower Silurian. Prof. Emmons could not wish the 

 assent of a more respectable authority, which cannot fail to secure the adhesion of all American geologists." 

 (Bulletin Seance de 4 Fevrier, 1861, p. 320.) Now we understand Sir William to suggest, that "these 

 shales and limestones (of Quebec and Georgia), are subordinate to the Potsdam sandstone" a deep sea 

 deposit, going on at the same time with the arenaceous deposit nearer the shore ; whereas Prof. Emmons 

 places his Taconic System below the Potsdam sandstone, in the same position as the Cambrian and Hu- 

 ronian System. Does he then recognize the Taconic System as understood by its author, or can it be 

 that Barrande has mistaken his meaning ? We apprehend that the discussion of this subject is yet only 

 begun. 



TALCOSE CONGLOMERATES. 



MAGNESIAN SLATES : First Annual Eeport upon the Geology of Vermont, 1845 ; by Prof. 

 C. B. Adams. 



Under this head we are about to describe rather an indefinitely defined group of rocks, 

 constituting what many would call the western part of the western range of the talcose 

 schist. It seems to be associated with the quartz rock in its south part, and may be of 

 the same age. Partly for this reason we have used the same color to designate the extent 

 of the two rocks, upon the Geological Map. 



Lithological Characters. 



The different varieties of rocks associated together in this belt are the following : 



1. Sandstones. 



2. Breccias. 



3. Quartz rock. 



. 4. Calcareous rocks. 



5. Novaculite schist. 



6. Talcose schist. 



7. Coarse conglomerates. 



The sandstones are few. Beds of sandstone may be seen near St. Albans, upon the 

 narrow spur running up to Aldis Hill from the main belt in Fairfax. They are of a dull 



