42 



in many instances into definite zones or horizons and smaller sub- 

 divisions, all of which were deposited under peculiar conditions such as 

 characterised the lower half of the Ordovician (Cambro-Silurian) Epoch 

 in geology. 



It will thus appear that the rocks constituting the Quebec terrane 

 (which term has b^en used and is b.-ing adopted by many American 

 geologists as a proper one with which to designate these so-called 

 "Hudson River" rocks) form part and parcel of the original " Quebec 

 Group" of Logan. 



The paper went on to refer to the faunas entom' ed in each of 

 these three divisions, care being taken to exclude from the list of 

 characteristic species — such forms as were not found in situ or (rom the 

 rocks proper of each series — whether from loose pieces or from 

 conglomerates or conglomerate like bands, in order that the possibilities 

 of error in orrelazion as well as in |)alKontological or fiunal differenti- 

 ation might be lessened in the problem which like the present one 

 affords such diver^iiy of relations and complicated terms. 



The paper is, in fact, a sequel to the writer's contribution read 

 before the Geological Society of America at Washington, last December 

 and published since. (See Bulletin of the Geological Society of Ani-i'-ica^ 

 Vol. II., pp. 477-502, plate 20, 189 [.) Whilst the latter dealt more 

 particularly with the region about Quebec City — the present one 

 referred to the relations and characteristics of the Quebec Group of 

 Logan and Billings throughout the whole extent of the Province ot 

 Quebec and contiguous districts, upon which to base the proofs for the 

 validity and actual existence of such a group or series of terranes in 

 that portion of North America. The equivalency of the term 

 " Canadian Period," or " Canadian Epoch," as used liy Prof James 

 D. Dana and others, is also adduced as further evidence, corroborative 

 of the magnificent work performed by Sir William Logan in elucidating 

 the complex structure of the Province of Quebec— which work with 

 the exception of Sir William Dawson, in several papers nnd reports — 

 found scarcely any advocate, whilst its factors are based upon principles 

 and data which are as durable as the rocks from which they proceed or 

 with which they are related. 





