6 A. R, C. SELWYN ON THE 
south-west corner and runs thence to the north line of the township in the vicinity of the 
twelfth lot. They are again traceable from the south-eastern part of Roxton, across the 
north-western part of Ely, the south-eastern corner of Acton, and thence through Durham 
to the St. Francis, which the south-eastern limit of them crosses about three miles below 
the line between this township and that of Melbourne. This limit, running thence through 
the whole length of Kingsey, and keeping about two miles, and sometimes rather less, from 
the division between it and Shipton, gains the Arthabasca road, which it follows through 
Warwick and Arthabaska, afterwards attaining the vicinity of ue line between Halifax 
and Somerset, which it keeps to the continuous one of Inverness.’ 
In the foregoing quotation the line is accurately described which I have quite inde- 
pendently traced and shewn on the map as the division between the fossiliferous and the 
crystalline portion of the Quebec Group, and we see it was then, 1847, very correctly recog- 
nized by Sir William Logan, as marking a distinct geological horizon ; and he compared 
the beds on the north-west side of it to the shales and limestones of Grantham and the 
Richelieu and Yamaska rivers in the following words: “These beds bear a strong resem- 
blance to the shales and limestones of Grantham, their mineral character being the same, 
and occasionally a feebler one (for no fossils are found in them) to the calcareous and arena- 
ceous shales of the Yamaska and Richelieu, except that they are firmer and harder; and 
it seems not improbable that this part of the section is a repetition of those measures.” 
Later the theoretical boundaries of the theoretical formations of Levis and Nillery, with 
the subsequently added Lauzon, into which the region was divided, were run diagonally 
across the true strike of the strata as above described, resulting in a map which, on exam- 
ination of it on the ground, I found to be perfectly incomprehensible, and opposed not only 
to every principle of stratigraphical mapping, but also to the mineralogical and palæontolo- 
gical evidence afforded by the rocks themselves. 
From Inverness, the north-easternmost point to which the belt was traced by Sir Wil- 
liam, it can be easily followed to the extreme point of the Gaspé peninsula, and has now 
yielded fossils throughout its entire length and breadth, though included in it are certain 
areas of red slate and sandstone (to which I shall again allude) in which no fossils have as 
yet been detected ; while in the other parts of its distribution the fossils indicate that both 
Hudson River, Trenton and Levis or Calciferous are included within the area. 
To the north-west the fossiliferous belt under description, composing the so-called 
Quebec group, is bounded, or supposed to be bounded, throughout its entire length from 
the Vermont boundary to the north end of the Island of Orleans, by what has been designa- 
ted the great St. Lawrence and Champlain fault, described on page 234 of the Geology of 
Canada, 1863. The character and course of this break I shall again refer to. 
To the south-east, the limit of the fossiliferous belt throughout a great part of the same 
distance is indicated by a marked step in the country, especially prominent from the village 
of St. Christopher, north-eastward through the townships of Inverness, North Halifax and 
Leeds. It is further marked by an entire absence to the south-east of any trace of fossils, 
and by the totally different aspect of the strata. In some parts of its course the line has 
much the appearance of a fault, though I have not yet found satisfactory evidence of its 
being so. It probably combines the features both of a fault and an unconformity. But 
whatever the nature of the line in its different parts may be, there can, it seems to me, be 
