8. _Potamogeton pusillus._ Quantities of fragments which I refer to this species occur in nodules at Green's Creek. They may possibly belong to a variety of _P. hybridus_ which, together with _P. natans_, now grows in the river Ottawa, where it flows over the beds containing these fossils.
9. _Cariceæ and Gramineæ._ Fragments in nodules from Green's Creek appear to belong to plants of these groups, but I cannot venture to determine their species.
10. _Equisetum scirpoides_, Michx. Fragments in nodules, Green's Creek. This is a widely distributed species, occurring in the Northern States and Canada.
11. _Fontinalis._ In nodules at Green's Creek there occur, somewhat plentifully, branches of a moss apparently of the genus _Fontinalis_.
[Illustration: Fig. 79.--Frond of _Fucus_. Pleistocene, Canada.]
12. _Algæ._ With the plants above mentioned, both at Green's Creek and at Montreal, there occur remains of sea-weeds (Fig. 79). They seem to belong to the genera _Fucus_ and _Ulva_, but I cannot determine the species. A thick stem in one of the nodules would seem to indicate a large _Laminaria_. With the above there are found at Green's Creek a number of fragments of leaves, stems, and fruits, which I have not been able to refer to their species, principally on account of their defective state of preservation.
None of the plants above mentioned is properly arctic in its distribution, and the assemblage may be characterised as a selection from the present Canadian flora of some of the more hardy species having the most northern range. Green's Creek is in the central part of Canada, near to the parallel of 46°, and an accidental selection from its present flora, though it might contain the same species found in the nodules, would certainly include with these, or instead of some of them, more southern forms. More especially the balsam poplar, though that tree occurs plentifully on the Ottawa, would not be so predominant. But such an assemblage of drift-plants might be furnished by any American stream flowing in the latitude of 50° to 55° north. If a stream flowing to the north, it might deposit these plants in still more northern latitudes, as the McKenzie River does now. If flowing to the south, it might deposit them to the south of 50°. In the case of the Ottawa, the plants could not have been derived from a more southern locality, nor probably from one very far to the north. We may therefore safely assume that the refrigeration indicated by these plants would place the region bordering the Ottawa in nearly the same position with that of the south coast of Labrador fronting on the Gulf of St. Lawrence at present. The absence of all the more arctic species occurring in Labrador should perhaps induce us to infer a somewhat milder climate than this.
