i^6 ^evieiv of (Recent Geological Literature. 
Dawson. (From the Transactions of the Rojal Society of Canada; read 
May, 1887). 
About sixty distinct trees, most of them found in situ, from the Belly 
River, Fort Pierre and Laramie groups, have been examined in thin 
slices by the author. He forbears to add any specific names, but remark-s 
that they probably have all been described before from specimens of 
their leaves and fruit. He refers them all to their generic names only. 
In the Belly River and Fort Pierre series he identifies Sequoia, the "big 
tree" of California, and the "redwood" of California; TaxHes, yew; 
Gitiko^o, similar to the Chinese ginkgo; Thuja, arbor vit;e; a Pinus or 
vl^'cs^.''), pine or spruce; Beiula,Pofulus, Carya, L'imus,Platatius(?). 
From the Laramie he identifies the same two types of Sequoia, the 
same Taxites, the same Ginkgo, Thuja, and Pinus (.'). He also here finds 
ypglans, Bettila, Populus, Acer. 
Other plants are as follows, from the Laramie, Onoclea sensihilis Lin, 
Sequoia couttsice Heer, Podocarpites tyrrdlii n. &p., Populus arciica Heer, 
and P. getietrix Newb., and nervosa, Salix laramiana Dn., Carya antiquorum 
Newb., Neluinbium saskatchucnse n. sp., Trapa borealis Heer, Viburnum 
saskatchuense n. sp., Vibernum asperurn l^ewh., and a Sapitidus which in 
near 6". obtusifolia Lesq. 
The author remarks in conclusion: 
An important geological consequence arising from this is, that the 
period of warm climate, which enabled a temperate flora to exist in Green- 
land, was that of the later Cretaceous and early Eocene, rather than, as 
usually stated, the Miocene. It is also a question admitting of discussion 
whether the Eocene species of latitudes so different as those of Greenland, 
Mackenzie river, N. W. Canada and the western states, were strictly 
contemporaneous, or successive within a long geological peorid in w hich 
climatal changes were gradually proceeding. The latter statement must 
apply at least to the beginning and close of the period; but the plants 
themselves have something to say in favour of contemporaneity- The 
flora of the Laramie is not a tropical but a temperate flora, showing no 
doubt that a much more equable climate prevailed in the more northern 
parts of America than at present. But this equability of climate implies 
the possibility of a great geographical range on the part of plants. Thus, 
it is quite possible, and indeed highly probable that, in the Laramie age, 
a somewhat uniform flora extended from the arctic seas through the 
great central plateau of America, far to the south, and in like manner 
along the western coast of Europe. It is also to be observed that, as 
Gardener points out, there are some differences indicating a diversity of 
climate between Greenland and England, and even between Scotland 
and Ireland and South of England, and we have similar differences, 
though not strongly marked, between the Laramie of northern Canada 
and that of the United States. When all our beds of this age, from the 
Arctic sea to the 49th parallel, have been ransacked for plants, and when 
the palasobotanists of the United States shall have succeeded in com- 
pletely unravelling the confusion which now exists between their Lara- 
mie and the Middle Tertiary, the geologist of the future will be able to 
restore with much certainty the distribution of the vast forests w hich, in 
the early Eocene, covered the now bare plains of interior America. Fur- 
ther, since the break which, in western Europe, separates the flora of 
the Cretaceous from that of the Eocene, does not exist in America, it 
will then be possible to trace the succession of plants all the way from 
