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Cyclopterus lumpus, Linn.

The lump sucker occurs in nodules at the same place.

Gasterosteus.

It

In nodules at the same place, found by Sheriff Dickson. closely resembles the two-spined stickleback of the Gulf St. Lawrence, but is not sufficiently perfect for description.

Vertebrae and other fragments of fishes not determinable, have been found at Rivière-du-Loup, and a bird's feather in a nodule on the Ottawa.

The Mammalia are represented in the marine Post-pliocene of Canada by Phoca Grænlandica, Muller, found in the Leda clay at Montreal, and Beluga Vermontana in the same situation, and also in the Saxicava sand at Cornwall (Billings). The latter I believe to be identical with the modern Beluga of the Gulf St. Lawrence.

In the superficial gravels of Ontario, probably more recent than the marine beds, remains of a fossil elephant, Euelephas Jacksonii, have been found, and have been described by Mr. Billings (Can. Nat. vol. VIII).

FOSSIL PLANTS.

The only locality where fossil plants in any considerable number have been obtained, is at Green's Creek on the Ottawa, where they owe their preservation to the nodules of calcareous matter that have enclosed delicate specimens which otherwise could not have been secured from the soft Leda clay in which the nodules are enclosed. In addition to specimens collected by myself, I have examined the collections made by the late Rev. Mr. Bell of L'Original, those of the late Sheriff Dickson, and those of the Geological Survey. The whole were described in my paper in the Canadian Naturalist for February, 1866, and since that time no new material of importauce has come into my hands. The species recognized are:

Drosera rotundifolia, Linn.
Acer spicatum, Lamx.
Potentilla Canadensis, Linn.
Gaylussacia resinosa, Jones.
Populus balsamifera, Linn.

Thuja occidentalis, Linn. (found at Montreal.)

Potamogeton perfoliatus, Linn.

Equisetum scirpoides, Michx.

Carices and graminea, fragments.

Fontinalis, sp.

Algae.

These plants occur in the marine Leda clay, containing its characteristic fossils, and were probably washed from the neighbouring land by streams. They indicate to some extent the flora of the Laurentian hills bordering the valley of the Ottawa, at the time of the Post-pliocene subsidence. The inferences as to climate deducible from them are stated in the following extract from the paper above referred to:

"None of the plants above mentioned are properly Arctic in their distribution, and the assemblage may be characterized 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 sonth 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 more mild climate than this.”

The climatic indications afforded by these plants are not dissimilar from those furnished by a consideration of the marine fauna of the period of the Leda clay.

Addenda to Echinodermata.

Mr. T. Curry of Montreal has been so fortunate as to find in the Leda clay near that city, in addition to fragments apparently of an Ophioglypha, a specimen probably of Ophiacantha spinulosa, Muller and Tr., and one of Solaster papposa, Linn. Both of these are species now found in the Gulf of St. Lawrence. Mr. Matthews has also obtained a second species of Ophiurid Starfish at St. John.

Summary of Fossils.

The above lists include, in all, about 205 species, being more than twice the number included in previous lists, and distributed as follows:

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The whole of these, with the three or four exceptions, may be affirmed to be living Northern or Arctic species, belonging in the case of the marine species, to moderate depths, or varying from the littoral zone to say 200 fathoms. The assemblage is identical with that of the northern part of the Gulf of St. Lawrence and Labrador Coast at present, and differs merely in the presence or absence of a few more southern forms now present in the Gulf, especially in its southern part, where the fauna is of a New England type, whereas that of the Post-pliocene may be characterized as Labradorian. As might have been anticipated from the relations of the Modern marine fauna, the species of the Canadian Post-pliocene are in great part identical with those of the Greenland seas and of Scandinavia, where, however, there are many species not found in our Post-pliocene. The Post-pliocene fauna of Canada is still more closely allied to that of the deposits of similar age in Britain and in Norway. Change of climate, as I have shewn in previous papers, having been much more extensive on the east than on the west side of the Atlantic, owing to the distribution of warm and cold currents resulting from the present elevation of the land.

It cannot be assumed that the fauna of the older part of the Canadian Post-pliocene is different to any great extent from that of the more modern part. Such difference as exists seems to depend merely on a gradual amelioration of climate. The shells of the lower Boulder clay, and of those more inland and elevated portions of the beds which may be regarded as older than those of the lower terraces near the coast, are undoubtedly more Arctic in character. The amelioration of the climate seems to have kept pace with the gradual elevation of the land, which threw the cold ice-bearing Arctic currents from its surface, and exposed a larger area of land to the action of solar heat, and also probably determined the flow of the waters of the Gulf Stream into the North Atlantic. By these causes the summer heat was increased, the winds both from the land and sea were raised in temperature, and the heavy northern ice was led out into the Atlantic, to be melted by the Gulf Stream, instead of being drifted to the southwest over the lower levels of the continent. Still the cold Arctic currents entering by the Straits of Belle-isle and the accumulation of ice and snow in winter, are sufficient to enable the old Arctic fauna to maintain itself on the Northern side of the Gulf of St. Lawrence, and to extend as far as the latitudes of Murray Bay and Gaspé. South of Gaspé we have the warmer New England fauna of Northumberland Strait. I may add that some of the peculiarities of the Post-pliocene fauna in comparison with that of the St. Lawrence river, indicate a considerable influx of fresh water, derived possibly from melting ice and snow.

PART III. - GENERAL CONCLUSIONS.

This Memoir has already extended to so great length, that I shall be under the necessity of dwelling as little as possible on the general geological truths deducible from the facts which have been stated. I shall specially refer to only two points: (1) The relation of the Post-pliocene fossils to questions of derivation of species; (2) The bearing of the facts above stated on theories of land glaciation.

On the first of these subjects I may remark that whatever may have been the lapse of geological time from the period of the oldest Boulder Clay to that in which we live, and great though the climatal and geographical changes have been, we cannot affirm that any change even of varietal value has taken place in

any of the 205 species of the above lists.

This appears to me a

fact of extreme significance with reference to theories of the modification of species in geological time. No geologist doubts that the Post-pliocene was a period of considerable duration. The great elevations and depressions of the land, the extensive erosions, the wide and thick beds of sediment, all testify to the lapse of time. The changes which occurred were fruitful in modifications of depth and temperature. Deep waters were shallowed, and the sea overflowed areas of land. The temperature of the waters changed greatly, so that the geographical distribution of marine animals was materially affected. Yet all the Post-pliocene species survive, and this without change. Even variable forms like the species of Buccinum and Astarte show the same range of variation in the Post-pliocene as in the modern, and though some varieties have changed their geographical position, they have not changed their character. This result is obviously independent of imperfection of the geological record, because there is no reason to doubt that these species have continuously occupied the North Atlantic area, and we have great abundance of them for comparison both in the Post-pliocene and the modern seas. It is also independent of any questions as to the limits of species and varieties, inasmuch as it depends on careful comparisons of the living and fossil specimens; and by whatever names we may call these, their similarity or dissimilarity remains unaffected. We have at present no means of tracing this fauna as a whole farther back. Some of its members we know existed in the Pliocene and Miocene without specific difference; but some day the middle tertiaries of Greenland may reveal to us the ancestors of these shells, if they lived so far back, and may throw further light on their origin. In the meantime we can affirm that the lapse of time since the Pliocene has not sufficed even to produce new races; and the inevitable conclusion is that any possible derivation of one species from another is pushed back infinitely, that the origin of specific types is quite distinct from varietal modification, and that the latter attains to a maximum in a comparatively short time, and then runs on unchanged, except in so far as geological vicissitudes may change the localities of certain varieties. This is precisely the same conclusion at which I have elsewhere arrived from a similar comparison of the fossil floras of the Devonian and Carboniferous periods in America.

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