

CRETACEOUS AND TERTIARY—PYRAMID CREEK. 95 
the type of Paludina ( Vivipara) trochiformis, M. & H. No shells, other 
than those of purely fresh waters, were found. 
228. The lower part of the section forms a group well distinguished 
by its colour and the perfection of its stratification from the upper, and 
often endures, protected by its hard sandstone (No. 2), when the more 
crumbling upper division has been removed. The plant remains, though 
occurring more or less throughout the whole section, are best preserved 
in the lower purplish layers. They consist chiefly of leaves of dicoty- 
ledonous trees, which appear to have fallen when mature, in the course 
of nature, and with the change of the seasons, and floated without 
violence to the great lake in the fine silty deposits of which they have 
been preserved. Populus, Cinnamomum, Quercus, and other forms, are 
represented. Leaves and small branches of coniferous trees, referable to 
Sequoia Langsdorfii, and Glyptostrobus Europeus, are particularly abun- 
dant at this place. Details concerning the fossil plants of the Lignite 
Tertiary, will however, be found on a subsequent page. 
229. Many of the crumbling hill-tops in this valley have a ik ed 
colour resembling that seen in parts of the Souris Valley, and due, as 
there, to the combustion in situ of the deposits of lignite. The slag or 
clinker produced by this action is also found here, though it was not 
observed actually in place. | 
230. The next stream crosses the Line at the 351 mile point; it also 
flows through a deep valley of erosion, and may be called Pyramid Creek, 
from a remarkable pyramidal hill formed of the usual clays and sands, 
capped by a portion of a layer of hard grey sandstone, the cement of 
which is calcareous. It has a tendency to break into large quadrangular 
masses along intersecting jointage planes, and shows conspicuous false- 
bedded structure. Below this is a thickness of about fifty feet of rather 
incoherent fine yellowish sand sometimes argillaceous. This, pro- 
ducing a sloping bank, is not very well seen, but constitutes about 
one-third of the thickness of the beds exposed in this valley. The middle 
third consists of soft crumbling sandstone or compact sand without any 
apparent cementing matter, and of which the constituent particles are 
rather coarse; contrasting strikingly in this respect with the overlying 
material. It shows evidence of having been deposited by water in rather 
rapid motion, through its entire thickness, but the false-bedding is very 
definitely cut off at many different horizons by perfectly horizontal 
planes, above which it again commences. The weather acting on these 
beds causes the hill sides composed of them to assume a well-marked 
