406 Canadian Record of Science. 
The contrast in the latter respectjis especially noticeable, 
for while the strata of the older series are everywhere 
highly inclined and sharply folded, those of the younger, 
along the line of contact, are very generally nearly flat. 
While, too, the former are largely made up of slates, often 
brilliantly or variously colored, and without conspicuous - 
fossils, the latter are usually grey or dark grey in colour, 
consist largely of limestones, and abound in corals and other 
organic remains, often of large size. The contrast in many 
places has been made still more striking by the effects of 
erosion. Thus along a large part of its northern edge, the 
Silurian presents the appearance of a bold or even precipi- 
tous escarpment, separated only by a deep and narrow 
valley from the irregular and usually lower tract to the 
north occupied by the inferior group. This feature is very 
strongly marked between the Grand Métis river and the 
Rimouski, determining in part the eminence of Mount 
Commis and wholly that of the Bois Brulé, and though to 
the westward of the Rimouski it becomes less evident, it 
re-appears with special prominence at Temiscouata Lake, 
here originating the remarkable eminence known as Mount 
Wissick, Mount Lennox or the Big Mountain. 
The order of succession and the equivalency of different 
members of the Silurian system in northern New Bruns- 
wick and adjacent portions of Quebec and Maine, have long 
been wrapped in much obscurity, the difficulty of their 
determination arising partly from the great sameness of 
the formation over large areas, the excessive folding and 
strong slaty cleavage by which it is generally characterized, 
and finally from the comparative paucity of fossils. An 
examination however of the section afforded by Lake Temis- 
couata and its vicinity has recently done much to remove 
this obscurity and to afford a key whereby the geology of 
the districts named may be more satisfactorily correlated 
not only with each other, but with more distant parts of 
the continent. 
It will not be possible in this place to dwell at length on 
the details of this section (which will be fully described in 
