
100 B. N. A. BOUNDARY COMMISSION. 
only in the larger and coarser leaves but in delicate ferns, which are here 
unusually common. The matrix is, however, unfortunately very soft; it 
crumbles easily, and tends to crack on drying. A considerable number 
of specimens of fossil plants from the vicinity of Porcupine Creek, have 
been preserved, though all in a more or less shattered condition. They 
are in the main identical with those of the Fort Union group, and include 
Glyptostrobus Europeus, Sequoia Langsdorffii, Thuja interrupta, Onoclea 
sensibilis, and one other species of fern; and examples of the leaves of 
many deciduous trees. For the identification of these fossils, and the 
notes on them which appear in a ionic chapter, I am indebted to 
Principal Dawson. 
No molluscous remains were found in any of the Porcupine Creek 
sections. 
Lignite Tertiary Rocks on the Traders’ Road to Wood Mountain. 
243. The furthest west of the sections in the vicinity of Porcupine 
Creek—that in which the eighteen-foot lignite occurs—is situated near 
the 393 mile point on the Line, and lies about thirty miles south-east of 
the trading settlement of half-breeds known as Montagne de Bois, Wood, 
or Woody Mountain. The point above indicated was the terminal one of 
the geological work of the season of 1873. Reverting now to Wood End, 
on the Souris River, the exposures of Lignite Tertiary rocks on the Trad- 
ers’ Road to Wood Mountain—which runs nearly parallel with, but to 
the north of the Boundary-line—require a brief notice. 
244, The section first met with is that already described as filling a 
gap in the sequence on the Line (§ 221.) Westward for about ninety 
miles, no beds underlying the drift and surface deposits are seen in the 
vicinity of the Traders’ Road. Beyond this point, however, for the re- 
mainder of the way to Wood Mountain—about thirty miles—many more 
or less perfect exposures of the rocks of the Lignite Tertiary occur. 
245. The road here follows along the northern slope of the water- 
shed plateau, or occasionally crosses over one of its projecting spurs. 
The whole region appears to be formed of rocks of Tertiary age, against 
which the drift deposits of the northern extension of the Coteau, else- 
where more fully described, are found to lie. 1 
246. The north-eastern exposure of this series is formed in a steep 
wooded hill, which forms the salient angle between two of the broad flat- 
bottomed vallies, so common in this region. The section consists of alter- 


