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The original copy was borrowed from, and filmed with, the kind consent of the following institution: Library, Geological Survey of Canada L'exemplaire filmA fut reproduit grflce d la g M/ NOTES ON THE POST-PLIOCENE GEOLOGY OF CANADA; With especial reference to the Conditions of Accumulation op the Deposits and the Marine Life of the Period. By J. W. DAWSON, LL.D., F.R.S., F. G. S. Irinripal of Ptilaiidicum—Ad\x\x specimen. St. Nicholas. 12a — Sculpture enlarged. Fig. 13. Choristes f/^^ww— (Carpenter)— Adult specimen. Montreal. 13a— Sculpture enlarged. Fig. 14. Capulus commodus—?\.. Levi, Quebec. 4.L^f,.C^^-t^^ *-♦ .£4<».i <»-f I THE POST-PLIOCKNE GEOLOGY OF CANADA. liv J. W. Daw. SON, LL.D., F.H.S., F.U.S. C N T E N T S . INTRODUCTORY. 1.— (iEXKU.VL DKSCUIPTION OF THE POST-PLIOCEXE FORMATIONS. II.— LOCAL DETAILS. III.— REVISION OF THE FOSSILS. IV.— COMrARISONS WITH MODERN PHEN'OMEXA, AND THEORETICAL DEDUCTIONS. Iittroihictori/. When in 1855 the writer, in conse(iuenoe of accepting the office of Principal of McGill College, was removed from the Carboniferous Districts of Nova Scotia, and thus to some extent debarred from the prosecution of his researches in the carbonifer- ous rocks of that Province and their fossil plants, he determined, with the advice of Sir W. E. Logan, then Director of the Geo- logical Survey of Canada, to take up as an occasional pursuit the study of the Drift Deposits of Canada, a work which had, at DAWSON — POST- PLIOCENE. (a.) (<;.; ("••) U'ast, this link of connection with previous occupations, that it related in part to marine animals, with which his Zoological studies on the sea coast had made him familiar. The results of" these studies have, in part, been pubiislied in the following papers : — (1.) On the Newer Pliocene and Post-Pliocene of the ^'ieinity of iNIontreal. — CmuiiUdti Xofiiraflsf, 1857. Additional Notes on the Post-]*lioccne Deposits of the St. Lawrence Valley.— /A. 1850. On the climate of Canada in the Post-Plioceno Period. — Ih. 1800. (4.) On Post-Tertiary Fossils from Labrador.— /A. 18G0. (5.) On the Geolojzy of Murray Bay (Part 3. Po.st-pliocene deposits)— //>. 1861. Address as President of the Natural History Society of Montreal.— //>. 18G4. On the Post-pliocene Deposits of Jliviere du Loup and Tadoussac— /6. 1865. (8.) Comparison of the Icebergs of Belle-isle and the Glaciers of Mont Blanc, with reference to the Boulder-clay of Canada.— 76. 18GG. (9.) On the Evidence of Fossil plants as to the Post-pliocene climate of Canada.- /i. 186G. In addition to these papers I placed in the hands of Sir W. E. J. ugun, all my notes and lists of fossils up to 1863, for his Report of that year ;'i- and gave a resumd of the subject, in so far as the Post-pliocene of the Acadian Provinces is concerned, in the second edition of my "Acadian Geology," published in 1808. Much of the matter contained in these detached publications now requires revision, more especially the lists of fossils; and many additional facts have accumulated. I purpose therefore now to summarize the facts and conclusions of my previous papers and to luiite them with the new facts, so as to present as complete a view as possible of the geology of the superficial deposits of Can- ada. I shall also prepare a complete list of the fossils up to date, witii revised nomenclature and synonymy. In this last part of the work I have been aided by Dr. P. P. Carpenter and Mr. Whiteaves. I have had the benefit, in the case of several critical species, of the advice of Mi*. J. G. Jeffreys, and Mr. R. MacAn- • Quoted in this paper as the " Geology of Canada." DAWSON — POST-PLIOCENE. 3 drew of London. I iiin also indebted to Mr. G. S. Brady for detonninin^ tlio Ostriicoda, to the Rev. H. W. Crosskey ibr oj)- portunitioH of eomparin^ .sir-cm mens with those of the Clyde Bed.s, and to Prof. T. K. Junes and J)r Parker and Mr. G. M. Dawsou for help with the Foraniinifera. The present memoir will, 1 am sure, be welcomed by all who arc engaged in the study of the subject to which it relates, if for no other reason, because the Poat-pliocenc deposits of Canada from their great extent and perfect development, are well fitted to throw light on many of the controversies which are 'low agi- tated with regard to these deposits. It may be proper here to indicate the nomenclature which will be followed. When the whole geological series is divided into Primary, Secondary, and Tertiary, the deposits to whicli this paper relate':? .re usually named Post-tertiary or Quaternary. These terms are, iu my judgment, unfortunate and misleading. If we take the relations of fossils as our guide, tlien, as Pictet has well remarked, whether we regard the land or the sea animals, there is no decided break between the Newer Pliocene and the Post-pliocene, the changes not being greater than those between the Pliocene and the older Tertiary ages. There is, therefore, no such thing in nature as a Quaternary time distinct from the Tertiary, as the Tertiary is distinct from the Secondary. Where therefore the terms Primary, Secondary, and Tertiary are used, the latter should include the whole time from the Eocene to the modern, inclusive, unless indeed the advent of man be considered an event of sufficient geological importance to warrant a separa- tion of the modern from the Tertiary period. When the terms Palaeozoic, Mesozoic and Kainozoic or Neozoic are used, then the two latter terms cover perfectly the Post-pliocene as well as the Eocene, Miocene and Pliocene. I would therefore include the Post-pliocene in the Neozoic or Tertiary period and define it to b. that geological age which is included between the Pliocene and the Recent. From the former it is separated by the advent of the cold or glacial* period, and the accompanying subsidence of the knd, as well as by the disappearance of many species of animals and plants. From the latter it is separated by the extinction of many mammalian • I use the term " glacial " in this paper in its general sense, aa including the action of floating ice as well as of land ice. 4 UAWSON — POS*r-PLIOCENE. forms and by the establishment of our continents at their present elevation above the water and with their present fauna and flora Jind dr.iiiinge .systems. In Canada the absence of the Pliocene deposits and the immediate superposition of the Post-pliocene on the Palaeozoic form:itioMs, remove all difficulty on the subject of the beginning of the period. The line of separation between the Post-pliocence and the recent, especially in Western Canada, is less distinct ; but in Eastern Canada the upper part of the Post- pliocene is always marine, while the recent deposits arc land and fresh-water. With regard to the subdivisions of the Post-pliocene in Canada, if we confine our attention to the clearly marked marine and glaci il beds of the lower part of the St. Lawrence A^alley, we have no difficulty in establishing the following divisions, suggested in my paper of 1857 : 4i. SdxlrtdHi Smiil, shallow-water sand and gravels, equivalent to the Champlain and Terrace epochs in part of Dana, to the modified drift of Hitchcock in part, to the Tertiary sands of Capt. Bayfield ; and to the Upper fossiliferous sands and gravels of Scotland and Scandinavia. 2. Lcda Cln;i, moderately deep-water clays, equivalent to lower part of Champlain epoch, Dana and Tertiary clays of Bavfiold. Fossiliferous Clays of Scotland and Scandi- uavia. ;}. Bnii/do'-Ciifi/. — Hard clay or sometimes sandy clay or sand, with stones and boulders, and not distinctly laminated. Equivalent +'> Glacial clays of Dana and unmodified drift of Hitchcock. Till and older Boulder clay of Scotland and Scandinavia. In Lower (y'auada these three deposits can often be seen in actual superposition, and the order is invariable. In some places all contain marine shells, in others these arc limited to the upper pfirt of the Leda clay or the lower part of the Saxicava sand. In Western Canada, around the great lakes, are extensively distributed beds of clay and gravel, which have been described in the Report of the Geological Survey, and which have afforded fresh- water and land remains only. Of these the Algoma sand and Saugeen clay and sand may possibly correspond in age to the Saxicava sand, and the Erie clay to the Leda clay. This iden- tification is, however, uncertain, as the marine Leda clay has been traced up no further than the vicinity of Kingston, on the St. DAWSON — POST-PLIOCENE. Lawrence, and of Arnprior on the Ottawa. Bulow these points tiie Valleys of the Ottawa and St. Lawrence present everywhere the deposits above tabulated, in a greater or less degree of com- pleteness. They are connected with the similar deposits of New England, through the valley of Lake Champluin, and across the low lands of Nova Scotia and New Brunswick. Whittlesey has described the "Western Drift Deposits in the Smithsonian Contributions, vol. xv., and according to him the lioulder drift is there the upper member of the series. More recently Prof Newberry has given a summary of the facts in his lleport of the Geological Survey of Ohio for 1SG9. From these sources I condense tlie following statements, The lowest member of the Western drift, corresponding to the Erie clays of the Canadian lleport, is very widely distributed and tills up the old ''olV'TS of the country, in some cases being two hundred feet or more in thickness. Toward the north these <;lays contain boulders and stones, but do not constitute a true Boulder-elay. They rest, however, on the glaciated rock sur- faces. They hav(! afforded no fossils except drifted vegetable ivemains. Above these clays are sands of variable thickness. They con- tain beds of gravel, and near the surface teeth of elephants have been found. On the surface are scattered boulders and blocks of northern origin, often of great size, and in some cases transported two hundred miles from their original places. More recent than all these deposits are the "Lake llidges" marking a former extension of the great lakes. Dr. Newberry considers the Eric clay to be the deposit of a period of submer- gence following the action of a continental glacier, and he main- tains that the old channels now filled with Erie clay are so deep as to indicate that in the earlier glacier period the land was at least five hundred feet higher than its present level. At the close of this period of submergence the boulder drift was deposited by northern currents and ice, and then the laud gradually rose to its present level. The facts thus summed up by Dr. Newberry indicate, in pro- ceeding from the older to the newer. 1 . An elevated continent and the erosion of deep valleys. 2. Claciation of th", surface. '.>. Filling of tiie valleys with Erie clay. 4. Distribution over the surface, of boulders and Northern drift. 6 DAWSON — POST-PLIOCENE. My interpretation of the phenomena would dificr I'rom that of Dr. Newberry in thcfollowingparticuhus — (1 ) I would refer the continental elevation and the deep erosion to the Pliocene period, before the advent of the glacial epoch. (2) I would refer the jilaciatcd surfaces and the lower part of tlie Erie clay to the time of the Canadian Boulder-clay, and would rouurd it as an evidence of subsidence and an ice-laden sea, with tlu; arctic current passiiit:' over the continent from the North-East. (3) I would regard the upper part of the Erie clay as equivalent to the Loda clay. (4) I would place the upper and confessedly water-borne drift as the equivalent of the Saxicava sand, and ijs belonging to the period of elevation. It is a difficulty, both in Dr. NewbL-rry's view and niiue, that marine shells are not found in the Erie clay and surface drift. The following considerations, however, dimiui.sh this. (1) The greater part of the Leda clay is very poor in fossils, even near the ocean, and so is the boulder clay. (2) The submergence of a vast continental area under cold water might have continued for a long time before the marine animals could widely spread them- selves over it, especially uuder the unfavourable circuuistances of ice erosion. (3) The few and scattered marine remains to be expected in these deposits may have escaped t»bservation. The occurrence of much drift-wood in the Krie clay is also, in my judgment, inconsistent with the occurrence of a general glacier immediately previous to the deposition of the clay. We may now consider the several members of the ]*ost-pliocene in succession. beginuinilifcrou s, containing especially Lcda truncafa, and often having boulders and large stones covered with Balanits IJcoiurl i\iid with Bryozoa, evidencing that they have for some time quietly repo.scd in the sea bottom before being buried in the clay. This is indeed the usual condition of the Boulder-clay in the lower part of the St. Lawrence Kiver. Further up, in the vicinity of 3Iontreal, it has not been observed to contain fossils, but it presents equally unequivocal evidence of sub-aqueous origin in the low state ol" oxidation of the iron in the blue clay, which becomes brown when exposed to the weather, and in the brightness of the iron pyrites contained in some of the glaciated stones, as well as in the pre- sence of rounded and glaciated lumps of Utica shale and other soft rocks, which become disintegrated at once when exposed to weathering, The true Boulder-clay is in all ordinary cases the oldest mem- ber of the Post-pliocene deposits, and it is not jiossible to ascer- tain the existence of Boulder-clays of different ages, superimposed on one another. It may be observed, however, that in so I'ar as the Boulder-clay is a marine tleposit, that which occurs at lower levels is in all probability newer than that which occurs at higher levels. It is also to be observed that boulders with layers of stones occasionally occur in the Leda clay ; and that the supcr- iicial sands and gravels .sometimes contain large boulders ; but these appearances are not, t think, sufficiently important to induce any experienced observer to mistake such overlying deposits Ibr the true Boulder clay. ^ -- - I In some localities the stones in the Boulder-day are almost exclusively those of the neighbouring rock formations, and this is C II M 1 8 DAWSON — POST I'LIOCKNE. Il( especially the case at the base of cliffs or proiuiiieiit outcro]i!«, whence a large quantity of material would be easily derived. In other cases material travelled from a distance largely predomi- nates. Throughout the valley of the Lower St. Jjawrence, the gneiss and other hard metamorphic rocks of the Laurentian hills to the north-east are very abundant, and in buuldo's of large size and much rounded. Occasional instauf^es also occur where boulders have been transported to the northwards; but these .are compara- tively rare. T have mentioned .some examples of this in Acadian Geology, p. 61. Similar instances are mentioned in the (Jcology of Canada, page 893. Though the boulder clay often prosints a >(jnK\vhat widely ex- tended and uniform sheet, yet it may be stated t(» till u\) all small valleys and depressions, and to be thin or absent on ridges and rising grounds. The boulders which it contains are also by no means uniformly dispersed. Where it is cut through by riveis. or denuded by the action of the si'a, ridges of boulders often appear to be included in it. Those on the Ottawa referred to in the " Geology of Canada," page 8!)o, are very good illustrations, and I have observed the same fact on the Lower St. Lawrence and on the coast of Nova Scotia. It is also observable that these lines and groups of boulders are often not of local material, but of rocks from distant localities, and that a number of the same kind .seem often to have been deposited together in one group. Loose boulders are often found upon the surface, and some- times in great numbers. In some instances these may represent beds of boulder clay removed by denudation. la other cases they may have been derived from the overlying members of the forma- tion, or may have been deposited on the surface, without any covering of clay or gravel. In "xVcadian Geology," p. 64, I have illustrated the manner iu which large stones, sometimes 8 feet or more in diameter, are moved by the coast ice and some- times deposited on t^ . surface of soft mud, and I have had ooca- sion to verify the observations of the same kind made by Admiral Bayfield, and quoted by Sir C. Lyell iu the " Principles of Geol- Oj_y." Lastly, on certain high grounds there are large loose boulders, which have probably been moved *j their present posi- tions by means of land ice or glaciers. The Boulder-clay not only presents, as above stated, indications of successive beds, but it occasionally contains surfaces on which lie large boulders striated and polished on the upper surface, in DAWSON POST-PLl >CEN K. 9 the niuuucr of the pavements of boulders describod by Miller, iis occurring in the Till of Scotland. These appearances arc, how- ever, rare, and few opportunities occur for observing them. A very general and important appearance is the polishing and striation of the underlying rocks usually to be observed under the Boulder-clay, and which is undoubtedly of the same ch; "ae- ter with that observed under Alpine glaciers. Th'.s continental striation or grooving is obviously the effect of the action of ice, and its direction marks the course in which the abrading agent travelled. This direction has been ascertained by the Canadian and Touted States Surveys, and l»y local observers, over a large part of Eastern America, and it presents some broad features well de.serving attention. A valuable table of the direction of this striation is given iu the (Jeology of Canada, which I may take as a basis for my remarks, adding to it a few local ob.servations of my own.-'"^ The table embraces one hundred and forty five observations, extending along the valleys of the St. Lawrence and the Ottawa and the borders of the great lakes. In all of these the direction is south, with an inclination to the West and East, or to state the case more precisely, there are two sets of striae, a Southwest set and a South-east set. In the table eighty-four are westward of South and fifty-eight are east- ward of South, three being due South. It further appears, when we mark the localities on the map, that in the valley of the St. Lawrence and the rising grounds bounding it, the prevailing course is South-west, and this is also the prevalent direction in Western New York, and behind the great Laurentide chain on the North side of Lake Huron. Crossing this striation nearly at right angles, is a second set, which occurs in the neck of land between Georgian IBay and Lake Ontario, in the valley of the Ottawa and in the hilly districts of the Eastern Townships of the Province of Quebec, where it is connected with a similar striation which is prevalent in the valleys of Lake Champlain and the Connecticut River and elsewhere in New England. In New England this striation is said to have been observed on hills 4800 feet high, as for ixample on Mansfield Mountain, where according to Hitchcock there are striae bearing S. 30° E. at an elevation of 4848 feet. In Nova Scotia and New Brunswick, as • See also, for the Western districts, Whittlesey's Memoir in the ^millisoniau Contributions, and NewbtiTy's Report on Ohio. 10 DAWSON — POST-PLIOCENE. i ll! in New England, tlie prevailing direction is South PJastward, though there are also South-west and South striation, and a few cases where the direction is nearly East and West. It is obvious that such striation must have resulted from the action of a solid mass or masses of ice bearing for a long time on the surface and abrading it by means of stones and sand. It is further obvious that the different sets of striation could scarcely have been produced at the same time, especially when, as is not infrequent, we have two sets nearly at right angles to each other in the same locality. Hence it becomes an important question to ascertain the relative ages of the striation and also the direc- tion in which the abrading force moved. Taking the valley of the St. Lawrence in the first instance, the crag-and-tail forms of the isolated hills of trap, like the Montreal mountain, with abrupt escarpments to the north-east and slopes of debris to the south-west, the quantity of boulders carried from them far to the south-west, and the prevailing striation in the same direction, all point to a general movement of detritus up the St. Lawrence valley to the south-west. Further, in some cases the striae themselves show the direction of the abrading force. For example, in a fine exposure recently made at the Mile-end quarries, near Montreal, the polished and grooved sur- face of the limestone shows four sots of striae. The principal ones have the direction of S. 68'= W. and S. C>0° W respectively. and the second of these sets is the stronger and coarser, and some- times obliterates the first. The two other sets are comparatively few and feeble striae, one set running nearly N. and S,, and the other N.W. and S.E. These last are probably newer than the two first sets. Now with regard to the direction of the principal sets of striae, this at the locality in question was rendered very manifest by the occurrence of certain trap dykes crossing the limestone at right angles to the striae. The force, whatever it was, had impinged on these dykes from the N. E., and their S. W. side had protected the softer limestone. The locality is to the North-east of the mass of trap constituting the Montreal mountain, and ♦he movement must have been up the St. Law- rence valley from the N.E., and toward the mountain, but at this particular place the striae point West of its ma.ss. This, I have no hesitation in saying, is the dominant direction in the St. Law rence valley, and it certainly points to the action of the arctic current passing up the valley in a period of submergence. Fur- DAWSON — rOST-PLIOCENE. 11 thcr, it is the Boulder-clay connected with this S. W. striation that has hitherto proved most ricli in marine shells. If, however, we pass from the 8t. Lawrence V^illoy up the valleys which open into it from the North, as for example the I and Nova Scotia, we must ascribe the glacia- tion either to general ice-laden currents from the North-west, or to the great continental glacier imagined by some geologists. A most important observation bearing on this subject appears in the Report of Mr. R. Bell, in he region of Lake Nipigon, North of Lake Superior. He observed there the prevailing South-west striation, but with a more westerly trend than usual. Crossing this, however, there was a southerl; and S. E. set of striae which were observed to be older than the South-west striae. In some other parts of Canada these striae seem to be newer than the others, but there would be nothing iiuprobable in their occur- ing both at the beginning and end of the Boulder-clay period. In summing up this subject, 1 think it may be affirmed that wheu the striation and transfer of materials have obviously been from N.E. to S.W., in the direction of the Arctic current, and more especially when marine remains occur in the drift, we may infer that floi'ting ice and marine currents have been the efficient agents. Where the striation has a local character, depending upon existing mountains and valleys, we may on the other hand infer the action of land ice. For many minor effijcts of striation, and of heaping up of moraine-like ridges, we may refer to the pre- sence of lake or coast ice as the land was rising or subsidins. This we now see producing such eflfects. and I think it has not been sufficiently taken into the account. As to the St. Lawrence valley, it is evident that its condition during the deposit of the Boulder-clay must have been that of a part of a wide sound or inland sea extending across the continent, and that local glaciers may have descended into it from the high lands on the north and possibly also on the south. During this state of the valley great quantities of boulders were brought down into it, especially from the Laurentide hills, and were drifted along the valley, principally to the south-west. Extensive erosion also took place by the combined action of frost, r.'.in, melting snows, and the arctic current and the waves, and thus was fur- nished the finer material of the Boulder-clay. D^ .VSON — POST- PLIOCENE. 18 It is I'uithcr to bo observed that oscillations of land inu.st be I taken into account in explaininj^ these phenomena. Elevations increasing the height and area of land might increase the space occupied by snow and land ice. Depressions, on the other hand, would bring larger areas under the influence of water-borne ice and marine deposits, and these might take place either in a sliallow sea loaded with field and coas: ice, or in deeper water in which large icebergs might float or gvound. There is reason to believe that such alternations were not infrequent in the Post- pliocene, and that their occurrence will explain many of the com- plexities of these deposits. Tfwe adopt the iceberg hypothesis, we must be prepared to consider in connection with this subject a subsidence so great as to place the Laurentides and all but the highest summits of the Appalachians under water. In this case a vast volume of Arctic ice and water would pour over the country of the great lakes to the S.W., while any obstruction occurring to the south would throw lateral currents over the Appalachians to the eastward. If we adopt the glacier hypothesis, we may on the other hand imngine a great movement of land ice to the S.W., westward of the Appalachians, and a separate outward movement eastward from these hills and down the Atlantic slope of America. On either hypothesis there arc difiiculties in accounting for some sets of striae, but on that l;ist-raontioncd I believe them to be insuper- able. It is evident from the descriptions of Smith, Geikie, Jameson, Crosskey, and others, that the Boulder-clay of Scotland and Scan- dinavia corresponds precisely in character with that of Canada, and there, as in America, the theory of a continental glacier has been resorted to for its explanation. The objections to this hpyo- thesis are very ably stated by Mr. Milne Home in a paper on the " Boulder-clay of Europe," in the Transactions of the Royal Society of Edinburgh, 1869. To this period and these causes must also be assigned the ex- cavation of the basins of the great American lakes. These have been cut out of the softer members of the Silurian and De- vonian Formations; but the mode of this excavation has been regarded as very mysterious ; and like other mysteriea has been referred to glaciers. Its real cause was obviously the flowing of cold currents over the American land during its submergence. The lake basins are thus of the same nature with the deep hollows u DAWSON — PnST-PLIOCENE. I ■ -I lii l!!! iiitorvouiiij^ botWL'oii the banks cast up by the Arctic currents on the present American coast, and like those deep channels of tlie Arctic current in the Atlantic recently explored by Dr. Carpenter. Their arrani^ement -i^eofrraphically as well as their croolojiical rela- tions, correspond with this view. Another consideration with roirard to the jrreat lakes deserves notice. ])r. Newberry has collected many facts to show that the lake basins are connected with '-"c another and with the sea by deep channels now tilled up with drift deposits. It is therefore ]>o,ssiolc that much of the erosion of these basins may have oc- curred before the advent of the i^lucial period, in the Pliocene age, when the American continent was at a higher level than at pres- ent. Dr. Newberry has given in t\w Report in the Geology of Ohio a large collection of facts a.«eertained by boring or otherwise, which go far to show that were the old channels cleared of drift and the continent slightly elevated, the great lakes would be drained into each other and into the ocean by the valleys of the Hudson and the Mississippi, without any rock cutting, and if the barrier of the Thousand Islands were then somewhat higher, the St. ]jawrence valley might have boen cut off from the basin of the great lakes. I shall close the discussion of this subject by (juoting from one of the papers above referred to, my views in 1864 ; reserving, however, some points respecting the present action of floating ice, to whi -h I shall refer in the sequel " Our American lake-basins are cut out deeply in the softer strata. Running wat'sr on the land would not have done this, for it could have no outlet ; nor could this result be effected by breakers. Glaciers could not have effected it ; for even if the climatal conditions for these were admitted, there is no height of land to give them momentum. But if we suppose the land sub- merged so that the Arctic current, flowing from the northeast, should pour over the Laurentian rocks on the north side of Lake Superior and Lake Huron, it would necessarily cut out of the softer Silurian strata just such basins, drifting their materials to the southwest. At the same time, the lower strata of the cur- rent would be powerfully determined through the strait between the Adirondac and Laurentide hills, and, flowing over the ridge of hard rock which connects them at the Thousand Islands, would cut out the long basin of Luke Ontario, heaping up at the same time in the lee of the Laurentian ridge, the great mass of boulder- • ' DAWSON — rORT-rHOCENK. 15 clay wlik'h iiitcrvoncs between Lake Ontario and (ioor;,'iun Buy. liake Erie may have been cut by tlie flow of tlie upper layers of water over the Miilulc 8>lurian escarpment ; and Lake Miehif^an, tliouj^h less closely connected with the directiim of the current, is, like the others, due to the action of a continuous erodinj; force on rocks of unequal hardness."' •' The ]>redoniinant southwest .striation, and the cutting of the ujjper hikes, demand an outlet to the west for the Arctic current. Jiut both during depression and elevation of the land, there must have been a time when this outlet was obstructed, and when the lower levels of New York, New England, and Canada were still und(!r water. Then the valley of the Ottawa, that of the Mohawk, and the low country between Lakes Ontario and Huron, and the valleys of Lake Champlain and the Connecticut, would be straits r»r arms of the sea, and the current, obstructed in its direct flow, would set principally along these, and act on the rocks in north and south and northwest and southeast directions. To this por- tion of the proce.«s T would attribute the northwest and southeast striation. It is true that this view docs not account for the southeast stria) observed ou some liigh peaks in New F gland ; but it must be observed that even at the time of greatest depres- sion, the Arctic current would cling to the northern land, or be thrown so rapidly to the west that its direct action might not reach such summits." " Nor would I exclude altogether the action of glaciers in eastern America, though I must dissent from any view which would assign to them the principal agency in our glacial phenomena, under a condition of the continent in which only its higher peaks were above the water, the air would be so moist, and the tempera- ture so low, that permanent ice may have clung about mountains in the temperate latitudes. The striation itself shows that there must have been extensive glaciers as now in the extreme Arctic regions. Yet I think that most of the alleged instances must be founded on error, and that old sea-beaches have been mistaken for moraines. Even in the White Mountains the action of the ocean-breakers is more manifest than that of ice almost to their summits; and though I have observed in Canada and Nova Scotia many old sea-beaches, gravel-ridges, and lake-margins, I have seen nothing that could fairly be regarded as the work of glaciers. The so-called moraines, in so far as my observation extends, are more probably shingle beaches and bars, old coast- fW fit II .; ,| 1 \m IG DAWaON— POST PLIOCENK. lines loiitlcd with bouUlers, or *' ozarH." Most of them convey to my mind the impression of ice-action albnj; a slowly Bubsidinj^ const, fbrminf; successive deposits of stones in the shullow water, and buryini; them- in clay and smaller stones as the depth in- creased. Thes*' deposits were nirain modified during emcrji;en('e, when the old rid;;es were (sometimes bared by denudation, and new ones heaped up." " I conclude these romarks with a mere reference to the alleged ])revalcnce of lake-basins and fiords in iiigh northern latitudes, as ennnectcd with glacial action. In reasoning on this, it seems to ]y\ overlooked that the prevalence of disturbed and mctamorphie rocks over wide areas in the north is one element in the matter. Again, cold Arctic currents are the cutters of basins, not the warm surface-currents. Further, the fiords on coasts, like the deep lateral valleys of mountains, are evidences of the action of the waves rather than of that of ice. I am sure that this is the case with the nuruerous indentations of the coast of Nova Scotia, which are cut into the softer and more shattered i)ands of rock, and show, in raised be; ohes and gravel ridges like those of tlie present coast, the levels of the sea atthe time of their formation." 2. The Lcda Clay. This deposit constitutes the subsoil over a large portion of the great plain of Lower Canada, varying in thickness from a few feet to 50 or perhaps even 100 feet in thickness, and usually resting on the Boulder clay, into which it sometimes appears to graduate, the material of the Lcda clay being of the same nature with the finer portion of the paste of the Boulder clay. Its name is de- rived from the presence in it of shells of Leihi truncata^ often to the exclusion of other fossils, and usually in a perfect state with both valves united. The Leda clay in its recent state is usually gray in colour, unctuous, and slightly calcareous. Some beds, however, arc of a reddish hue ; and in thick sections recently cut, it can be seen to present layers of different shades and occasional thin sandy bands, as well as layers studded with small stones. It sometimes holds hard calcareous concretions, which, as at Green's creek on the Ottawa, are occar iuually richly fossiliferous, but more usually arc destitute of fossil remains. When dried, the Leda clay becomes of stony hardness, and when burned it assumes a brick-red colour. When dried and levigated it nearly always affords some foramin* ifera and shells of ostracoids ; and in this as well as in its colour DAWSON — POST-PLIOCENE. 17 and texture, it clo«oly rcsci blcs the blue mud now iu process of deposition iu tho deeper parts of the Gulf of St. Lawrence. The luujination of tho Lcdu clay and its included sand layers, sliow that it was deposited at intervals, between whleli intervened sfjaces when currents carried small quantities of sand over the surface. Tn tliese intervals shells as well us sand were washed over the bottom, while o'dinar'ly Lcda, Nucula and Astarte bur- rowed in the clay itself. The liycrs and patches of stones I attribute to deposit from floo linj;:,' .ce, and to the same cause nmst bo attributed the large Laurentian boulders, occasionally thou;ih rarely seen imbedded in the clay. The material of the Lcda clay has been derived mainly from the waste of the lower Silurian shales of the Quebec and Utica groups, which occupy a great space in the basin of the Clulf and River St. Lawrence. The driftage of this material has been to the South-west, and in that direction it becomes thinner and finer in texture. The supply of this mud, under the action of the waves, of streams, of the arctic currents and tidal currents, and floating ice, must have been constant, as it now is in the Gulf and Kivcr St. Lawrence. It would be increased bv the melting of the snows iu spring and by any oscillations of level, and it is probably iu these ways that we should account for the alterna- tions of layers in the deposit. The modern deposit iu tho Gulf of St. Lawrence, the chemical characters and coloration of which T explained many years ago,^' shows us that the Leda clay when in suspension was probably reddish or brown mud tinted with peroxide of iron, like that which we now see in the lower St. Lawrence ; but like the mo- dern mud, so soon as deposited in the bottom, the ferruginous colouring matter would in ordinary circumstances be deoxidised by organic substances, and reduced to the condition of sulphide or carbonate of the protoxide. This colour, owing to its imperme- ability, it still retains when elevated out of the sea ; but when heated in presence of air, or exposed for some time at the surface, it becomes red or brown. The occasional layers of reddish Lcda clay indicate places or times when the supply of organic matter was insufficient to deoxidise the iron present in the mass. The greater part of the Leda clay was probably deposited in water of from twenty to one hundred fathoms in depth, corres- Journal of Geological Society >f London, vol. v. pp. 25 to 30. "r 18 DAWSON — POST PLIOCENE. ponding to the ordinary depths of the present Gulf of St. Law rence ; and as we shall find, this view is confirmed by the preva- lent fossils contained in it, more especially the Foraminifera. The most abundant of these in the Leda clay is Polystomclla stria to- punctata var. arctica, which is now most abundant r.i about twenty-five to thirty fathoms. Since, however, the shallow-water marine Post-pliocene beds extend upwards in some places to a height of six hundred feet on the hills on the north side of the St. Lawrence, it is probable that deposits of Leda clay contem- poraneous with these high-level marine beds were formed in the lower parts of the plain at depths exceeding one hundred fathoms. The Western limits of the Leda clay appear to occur where the Laurentian ridge of the Thousand Islands crosses the St. Lawrence, and where the same ancient rocks cross the Ottawa ; and in general the Leda clay may be said to be limited to the lower Silurian plain and not to mount up the Laurentian and metamorphic hills bounding it. Since, however, the level of the water, as indicated by the Terraces in Lower Canada, and by T^j^^^e.^/^ the probable depth at which the Leda clay was deposited, would -, /, \ carry the sea level far beyond the limits above indicated, and ^a^c^ ?, ^'ieven to the base of the Niagara escarpment, we must suppose, ^ ^ij^^'S"*^ either — (1) that the supply of this sediment failed toward the l/ijy^'^/ west ; or (2) that it has been removed by denudation or worked over again by the fresh waters so as to lose its marine fossils ; or (3) that the relative levels of the Western and Eastern parts of Canada were different from those at present. As already stated there are indications that the first may be an element in the cause. The second is no doubt true of the clays which lie in the immediate vicinity of the lake basins. There are, as yet no cer- tain evidences of the third ; but the facts previously stated on the authority of Dr. Newberry, lend it st me countenance ; and detailed surveys of the Terraces and raised beaches would be required to determine it. I believe, however, that much more rigorous investigations of the clays of Western Canada are re- quired before we can certainly affirm that none of them are marine. I believe the Leda clays throughout Canada to constitute in the main one contemporaneous formation. Of course, however, it must be admitted that the deposit at the higher levels may have ceased and been laid dry while it was still going on at lower ^ ex.' DAWSON— POST-PLIOCENE. 19 levels nearer the sea, just as a similar deposit still continues in the Gulf of St, Lawrence. On the whole, then, while wo regard this as one bed stratigraphically, we may be prepared to find that in the lower levels the upper layers of it may be somewhat more modern than those portions of the deposit occurring on higher ground and farther from the sea. Where the Leda clay rests on marine Boulder-clay, the change of the deposits implies a diminution of ice- transport relatively to deposition of fine sediment from water; and with this more favourable circumstances for marine animals. This may have arisen from geographical changes diminishing the supply of ice from local glaciers, or obstructing the access of heavy icebergs from the Arctic regions. At the present time, for example, the action of the heaviest bergs is limited to the outer coasts of La- brador and Newfoundland, and a deposit resembliug the Leda clay is forming in the Gulf of St. Lawrence ; but a subsidence which would detfrmine the Arctic current and the trains of heavy bergs into the Gulf, would bring with it the conditions for the formation of a Boulder-clay, more especially if there were glaciers on the Laurentide hills to the north. Where the Leda clay rests on Boulder-clay, which may be supposed to be of terres- trial origin, subsidence is of course implied ; anvl it is interesting to observe that the conditions thus required are tbe reverse of each other. In other words, elevation of land or sea bottom would be required to enable Leda clay to take the place of marine Boulder-clay, but depression of the land would be necessary to enable Leda clay to replace the moraine of a glacier. I c innot say, however, that I know any case in Canada where I can cer- tainly affirm that this last change has occurred ; thougb on the north shore of the St. Lawrence there are cases in which the Leda clay rests directly on striated surfaces which might be attributed to glaciers ; just as in the West vhc Erie clay occupies this posi- tion. 3. The Saxlcava Sand. When this deposit rests upon the Leda clay, as is not unfre- quently the case, the contact may be of either of two kinds. In some instances the surface of the clay has experienced much denudation, being cut into deep trenches, and the sand rests abruptly upon it. In other cases there is a transition from one deposit to the other, the clay becoming sandy and gradually pass- ' 'm M'". I ill''/ i |l ! Iil< S !i^ ! I 'il,'i'; ■ ■; 20 DAWSON — POST-PLIOCENE. ing upwards into pure sand. la this last case the lower part of the sand at its junction ^vith the clay is often very rich in fossils, showing that after the deposition of the clay a time of quiescence supervened with favourable conditions for the existence of marine animals, before the sand wr.3 deposited. It is usually, indeed, in this position that the greater part of the shells of our Post-plio- cene beds occur ; the toaxicava sand being generally somewhat barren, or containing only a few shallow-water species, while the Leda clay is usually also somewhat scantily supplied with shells, except toward its upper layers. Hence it is somewhat difficult to refer a large part of the shells to either deposit, I have however usually regarded the richly fossiliferous deposit as belonging to the Leda clay ; and where, as sometimes happens, the clay itself is absent and merely a thin layer rich in fossils separates the Saxicava sand from the Boulder-clay, I have regarded this layer as the re- presentative of the Leda clay. The Saxicava sand, in typical localities, consists of yellow or brownish quartzose sand, derived probably from the waste of the Potsdam sandstone and Laurentian gneiss, and stratified. It often contains layers of gravel, and sometimes is represented alto- gether by coarse gravels. It is somewhat irregular in its distri- bution, forming banks and mounds, partly no doubt in consequence of original irregularities of deposit, and partly from subsequent denudation. In some outlying localities it is liable to be con- founded with the modern river sands and gravels. Large trav- elled boulders often occur in it ; but it rarely contains glaciated stones, the stones and pebbles seen in it being usually well rounded. From the nature of the Saxicava sand, it is obvious that it must be a shallow water deposit, belonging to the period of emer- gence of the land ; and it must have been originally a marginal and bank deposit, depending much for its distribution on the movement of tides and currents. In some instances, as at Cote des Neiges, near Montreal, and on the Terraces on the Lower St. Lawrence, it is obviously merely a shore sand and gravel, like that of the modern beach. Eidges of Saxicava sand and gravel have often been mistaken for moraines of glaciers ; but they can generally be distinguished by their stratified character and the occasional presence of animal remains, as well as by the water- worn rather than glaciated appearance of their stones and pebbles. T>AW80N — I'OST-PLIOCENE. 21 The Saxicavii saud sometimes rests on the Lcda clay or Boulder clay and sometimes directly on the rock, and the latter is often striated below this deposit ; but in this case there is generally reason to believe that Boulder-clay has been removed by denuda- tion. 4, Terraces and Inland Sea Ch'ffx. These are closely connected with the deposits last mentioned, inasmuch as they have been formed by the same recession of the sea wliich produced the Saxicava sand. At Montreal, where the isolated mass of trap flanked with Lower Silurian beds< constituting Mount Royal, forms a great tide-guage for the re- cession of the Post- pliocene sea, there are four principal sea mar- l_,ins with several others less distinctly marked, ""he lowest of these, at a level bout 120 feet above the level of the sea at Lake St, Peter, y be considered to correspond with the general level of the great plain of Leda clay in this part of Canada. On this Terrace in many places the Saxicava sand forms the surface, and the Leda and Boulder-clay may be seen beneath it. This may be called at Montreal the Sherbrooke St' eet Terrace. An- other, the Water- work Terrace, is about 220 feet higli, and is marked by an indentation on the Lower Silurian limestone. At this level some Boulder-clay appears, and in places the calcareous shales are decomposed to a great depth, evidencing long .sub- aerial action. Three other Terraces occur at heights of 386, 440, and 470 feet, and the latter has, at one place above the village of Cote dcs Neiges, a beach if sand and gravel with Saxicava and other shells. Even on the top of the Mountain, at a height of about 700 feet, large travelled Laurentian boulders occur. On the Lower St. Lawrence, below Quebec, the series of Terraces is generally very distinctly marked, and for the most part the lower ones arc cut into the Boulder and Leda clays, which are here of great thickness. I give below rough measurements of the series as they occur at Les Eboulcments, Little Mai Bay and Murray Bay, where they are very well displayed. I may remark in general with respect to these Terraces, that the physical conditions at the time when they were cut must have been much the same with those which exist at present, the appearances presented being very Bimilar to those which would occur were the present beach to be elevated. if t-ll DAWSON— POST-PLIOCENE . TERRACES LOWER ST. LAWRENCE. '!'■ '■ lleiyhta in English feet, rouifhly taken with Locke' n Level and Aneroiii. Jt ill: BS EbOI'LKMENTS. 1'ktitk Mal Hay. MuHRAY Bay 900 t)60 748 479 505 448 378 325 318 312 226 239 281 139 116 145 116 81 22 26 30 With reference to the differences in the above heights, it is to be observed that the Terraces themselves slope somewhat, and arc uneven, and that the principal Terraces are sometimes complicated by minor ones dividing them into little steps. It is thus somewhat difficult to obtain accurate measurements. There seems, however, to be a general agreement of these Terraces, and this I have no doubt will be found to prevail very extensively throughout ^he Lower St. Lawrence. It will be seen that three of the principal Terraces at Montreal correspond with three of those at Mui ;iy Bay ; and the following facts as to other parts of Canada, gleaned from the Reports of the Survey and from my own observations, will serve farther to illustrate this : Kemptville, sand and littoral shells, 250 feet. Winchester, io, 300 Kenyon, do. 270 Lochiel, do. 264 & 290 Hobbes' Falls, Fitzroy, do. 350 Dulham Mills, DeL'Isle, do. 289 Upton, 257 The evidence of sea action on many of these beaches, and the accumulatiou of shells on others, point to a somewhat long resi- dence of the sea at several of the levels, and to the intermittent elevation of the land. On the wider Terraces, at several levels it is usual to see a deposit of sand and gravel corresponding to the Saxicava sand. ii;;: 111': DAWSON— POST-PLIOCENE. m In the following table I have endeavoured to represent to the eye the facts observed in the internal plain of the great Lakes, and in the marginal area of the Atlantic slope, with the mode of accounting for thorn on the rival theories of glacier ice and floating ice. TABULAR VIEWS OK GLACIAL DEPOSITS AND THEORIES. Facts ohacrved. 1 Theoretical Views. 1 INLAND PLAINS. MARGINAL AIieAS. GLACIER THEORIES FLOATING-ICE THEORIES. Terraces. Terraces and raiiiod beaches. Emergence of modern Land. Travelled boulders and glaciated stones and rocks. Strati 1 ed sand and Kravel. (Algoma sand, &c.) Sand and gravel, with sea shells and boulders. (Saxicava sand). Shallow Seas and Flouting Ice. Stratified clay with drift-wood, and a few stones and boulders. (Erie clay.) Striated rocks. Stratified clay with sea shells. (Leda clay). Clay and boulders with or without sea shells. (Boulder-clay). Striated rocks. Deep water with Floating lee. Submergence of the land. Great continental mantle of Ice. Much floating ice and local glaciers. Submergence of Pliocene land. Old channels, indi- cating a higher level of the land. Old channels indi- cating previous dry land. 1 ! Erosion by conti- nental glaciers. Erosion by atmos- pheric agencies, & accumulation of decomposed rock. It will be observed that the theoretical views diverge with respect mainly to the Boulder-clay and the striation under the Erie clay, and to the cause of the erosion of valleys in the Pliocene land. I would merely remark, in addition to the considerations already advanced, that the occurrence of drift-wood in the Erie clay, and of sea shells in the Boulder-clay, are both most serious objections to the glacier hypothesis, reserving for the sequel a more full discussion of the rival theories. While the marginal marine area strictly corresponds to the marginal areas of Europe, I have no distinct evidence that the internal plains and table lands of the old continent correspond in their formations to the internal lake area of America. An interesting fact with reference to the Erie clay, stated in the Report of the Survey of Canada is, that these clays bum into ''1 r. 1 1 1 1 m'\ '■' i! I i 1 } i : 1 >' 1 1 j i j 1 1 24 DAWSON — P08T-1> L IOC EN K . ■!! i; ! liihl !i fir ■ irl white brick, while tlic marine Lcda chiy buriiH into red brick. The chemical cause of this I have already referred to, but whether it implies that the inland clays are fresh-water, or only that tbc}' have been derived from a different material, is uncertain. The gray clays of the Hudson River series in Western Canada, might, according to Mr. Bell, have afforded such clays. Under the theory of a glacial sea immediately succeeding the elevated Pliocene land, the great amount of decomposed rocks which must have accumulated upon the latter constitutes an im- portant element in the estimation of the rate of deposit of the Erie and Boulder and Leda clays. It is also to be observed that this glacial sea might have had to scour out of the lake basins of Canada only the soft mud of its own deposition, the rock-excava- tion having apparently been in great part effected in the previous Pliocene period. On this subject I find that Dr. Sterry Hunt had, before the publication of Dr. Newberry already alluded to,* shown that not only channels but considerable areas about Lakes Krie and St. Clair had been deeply excavated in the palaeozoic rocks and filled with Post-pliocene deposits. The Devonian strata, he remarks, " are found in the region under consideration at depths not only far beneath the water level of the adjacent Lakes Erie ard St. Clair, but actually below the horizon of the bottom of these shallow lakes." He shows that around these in various localitios the solid rocks are only met with at depths of from one to trvo hundred feet below the level of the lakes, while " the greatest depth of Lake St. Clair is scarcely thirty feet and that of the South-western half of Lake Erie does not exceed sixty or severity feet, so that it would seem that these present lake basins have been excavated from the Post-pliocene clays, which, in this region, fill a great ancient basin previously hollowed out of the palaeozoic rocks, and including in its area the South- western part of the peninsula of Ontario." It would thus appear that in the Pliocene period the basin of the lakes may have been a great plain w'th free drainage to the sea. Whether or not it was afterwards occupied by a glacier, this plain and its channels leading to the ocean were filled with clay at the beginning of the Post-pliocene subsidence ; and at a later date the mud vas again swept out from those places where the Arctic current could most powerfully act on it. • On the Geology of South-western Ontario. Am. Jour. Sci. 1868 DAWSON — POST-PLIOCENE. 17 and texture, it closely resembles the blue mud now iu process of deposition in tlie deeper parts of the Gulf of St. Lawrence. The lamination of the Leda clay and its included sand layers, show that it was deposited at intervals, between which intervened spaces when currents carried small quantities of sand over the surface. In tliese intervals shells as well iis sand were washed over the bottom, while ordinarily Leda, Nucula and Astarte bur- rowed in the clay itself. The layers and patches of stones I attribute to deposit from floating ice, and to the same cause must be attributed the large Laurentian boulders, occasionally though rarely seen imbedded in the clay. The material of the Leda clay has been derived mainly from the waste of the lower Silurian shales of the Quebec and Utica groups, which occupy a great space in the basin of the (jiulf and River St. Lawrence, The driftage of this material has boon to the South-west, and in that direction it becomes thinner and finer in texture. The supply of this mud, under the action of tlie waves, of streams, of the arctic currents and tidul currents, and floating ice, must have been constant, as it now is in the (lulfaud River St. Lawrence. It would be increased bv the melting of the snows in spring and by any oscillations of level, and it is probably in these ways that wc should account for the alterna- tions of layers in the deposit. The modern deposit in the Gulf of St. Lawrence, the chemical characters and coloration of which I explained many years ago,* shows us that the Leda clay when in suspension was probably reddish or brown mud tinted with peroxide of iron, like that which we now see in the lower St. Lawrence ; but like the mo- dern mud, so soon as deposited in the bottom, the ferruginous colouring matter would in ordinary circumstances be deoxidised by organic substances, and reduced to the condition of sulphide or carbonate of the protoxide. This colour, owing to its imperme- ability, it still retains when elevated out of the sea ; but when heated in presence of air, or exposed for some time at the surface, it becomes red or brown. The occasional layers of reddish Leda clay indicate places or times when the supply of organic matter was insufficient to deoxidise the iron present in the mass. The greater part of the Leda clay was probably deposited in water of from twenty to one hundred fathoms in depth, corres- A >^'> 0^" * Journal of Geological Society of London, vol. v. pp. 25 to 30. 18 DAWSON — POST PLIOCENE. i;i^ ponding to the ordinary depths of the present Gulf of St. Law rence ; and as wo shall find, this view is confirmed by the preva- lent fossils contained in it, more especially the Foraminifera. The most abundant of these in the Leda chiy is Polj/stomdla striato- jntnctata var. arctica, which is now most abundant at about twenty-five to thirty fathoms. Since, however, the shallow-water marine Post-pliocene beds extend upwards in some places to a height of six hundred feet on the hills on the north side of the St. Lawrence, it is probable that deposits of Leda clay contem- poraneous with these high-level marine beds were formed in the lower parts of the plaii at depths exceeding one hundred fathoms. The Western limits of the Leda clay appear to occur where the L.turentian ridge of the Thousand Islands crosses the St. Lawrence, and where the same ancient rocks cross the Ottawa ; and in general the Leda clay may be said to be limited to the lower Silurian plain and not to mount up the Laurentian and metamorphic hills bounding it. Since, however, the level of the water, as indicated by the Terraces in Lower Canada, and by the probable depth at which the Leda cluy was deposited, would carry the sea level far beyond the limits above indicated, and even to the base of the Niagara escarpment, we must suppose, either — (1) that the supply of this sediment failed toward the west ; or (2) that it has been removed by denudation or worked over again by the fresh waters so as to lose its marine fossils ; or (3) that the relative levels of the Western and Eastern parts of Canada were different from those at present. As already stated there are indications that the first may be an element in the cause. The second is no doubt true of the clays which lie in the immediate vicinity of the lake basins. There are, as yet no cer- tain evidences of the third ; but the facts previously stated on the authority of Dr. Newberry, lend it some countenance ; and detailed surveys of the Terraces and raised beaches would be required to determine it. I believe, however, thut much more rigorous investigations of the clays of Western Canada are re- quired before we can certainly affirm that none of them are marine. I believe the Leda clays throughout Canada to constitute in the main one contemporaneous formation. Of course, however, it must be admitted that the deposit at the higher levels may have ceased and been laid dry while it wa9 still going on at lower DAWSON — POST-PLIOCENE. n ■'::ti levels nearer the sea, just as a similar deposit still coDtiaues in the Qulf of St. Lawrence. On the whole, then, while wo regard this as ono bed stratigraphically, we may be prepared to find that in the lower levels the upper layers of it may be somewhat more modern than those portions of the deposit occurring on higher ground and farther from the sea. Where the Leda clay rests on marine Boulder-clay, the change of the deposits implies a diminution of ice-transport relatively to deposit. on of fine sediment from water; and with this more favourable circumstances for marine animals. This may have arisen from geographical changes diminishing the supply of ice from local glaciers, or obstructing the access of heavy icebergs from the Arctic regions. At the present time, for example, the action of the heaviest bergs is limited to the outer coasts of La- brador and Newfoundland, and a deposit resembling the Ledu clay is forming in the Gulf of St. Lawrence ; but a subsidence which would determine the Arctic current and the trains of heavy bergs into the Gulf, would bring with it the conditions for the formation of a Boulder-clay, more especially if there were glaciers on the Luurentide hills to the north. Where the Leda clay rests on Boulder-clay, which may be supposed to be of terres- trial origin, subsidence is of course implied ; and it is interesting to r'>serve that the conditions thus required are the reverse of each other. In other words, elevation of land or sea bottom would be required to enable Leda clay to take the place of marine Boulder-clay, but depression of the land would be necessary to enable Leda clay to replace the moraine of a glacier. I c innot say, however, that I know any case in Canada where I can cer- tainly ajfirm that this last change has occurred ; though on the north shore of the St. Lawrence there are cases in which the Leda clay rests directly on striated surfaces which might be attributed to glaciers ; just as in the West the Erie cluy occupies this posi- tion. 3. The Saxicava Sand. •vi When this deposit rests upon the Leda clay, as is not unfre- quently the case, the contact may be of either of two kinds. In some instances the surface of the clay has experienced much denudation, being cut into deep trenches, and the sand rests abruptly upon it. In other cases there is a transition from one deposit to the other, the clay becoming sandy and gradually pass- ■■;(, 20 DA^VHON — POST-PLIOCENE. 1^' .1-i ::i 'I: jlil ing upwards into pure sand. In this last case the lower part of the sand at its junction with the clay is often very rich in fossils, showing that after the deposition of the clay a time of quiescence supervened with favourable conditions for the existence of marine animals, before the sand was deposited. It is usually, indeed, in this position that the greater part of the shells of our Post-plio- cene beds occur ; the Saxicava sand being generally somewhat barren, or containing only a few shallow-water species, while the Leda clay is usually also somewhat scantily supplied with shells, except toward its upper layers. Hence it is somewhat diflBcult to refer a large part of the shells to either deposit, I have however usually regarded the richly fossiliferous deposit as belonging to the Leda day ; and where, as sometimes happens, the clay itself is absent and merely a thin layer rich in fossils separates the Saxicava sand from the Boulder-clay, I have regarded this layer as the re- presentative of the Leda clay. The Saxicava sand, in typical localities, consists of yellow or brownish quartzose sand, derived probably from the waste of the Potsdam sandstone and Laurentian gneiss, and stratified. It often contains layers of gravel, and sometimes is represented alto- gether by coarse gravels It is somewhat irregular in its distri- bution, forming buuks and mounds, partly no doubt in consequence of original irregularities of deposit, and partly from subsequent denudation. In some outlying localities it is liable to be con- founded with the modern river sands and gravels. Large trav- elled boulders often occur in it ; but it rarely contains glaciated stones, the stones and pebbles seen in it being usually well rounded. From the nature of the Saxicava sand, it is obvious that it must be a shallow water deposit, belonging to the period of emer- gence of the land ; and it must have been originally a marginal and bank deposit, depending much for its distribution on the movement of tides and currents. In some instances, as at Cote des Neiges, near Montreal, and on the Terraces on the Lower St. Lawrence, it is obviously merely a shore sand and gravel, like that of the modern beach. Ridges of Saxicava sand and gravel have often been mistaken for moraines of glaciers ; but they can geuorally be distinguished by their stratified character and the occasional presence of animal remains, as well as by the water- worn rather than glaciated appearance of their stones and pebbles. 1IAW80N — I'OST-IMJOCKNK. 21 Tho Saxicava aarnl sometimes rests on the Leda clay or Uuulder clay and sometimes directly on the rock, and the latter is often striated below this deposit ; but in this case there is generally reason to believe that Boulderclay has been removed by denudtt' tion. 4. TenxiCfH and Inland Sea C/i'Jj's. These are closely connected with the deposits last mentioned, inasmuch as they have been formed by the same recession of the sea which produced the Saxicava sand. At Montreal, where the isolated mass of trap flanked with Lower Silurian bedsi constituting Mount Royal, forms a great tide-guage for the re- cession of the Post pliocene sea, there are four principal sea mar- gins with several others less distinctly marked. The lowest of these, at a level of about 120 feet above the level of the sea at I^/ikeSt. Peter, may be considered to correspond with the general level of the great plain of Leda clay in this part of Canada. On this Terrace in many places the Saxicava sand forms the surfncf', and the Leda and Boulder-clay may be seen beneath it. This may be called at Montreal the Sherbrooke Street Terrace. An- other, the Water- work Terrace, is about 220 feet high, and is marked by an indentation on the Lower Silurian limestone. At this level some Boulderclay appears, and in places the calcareous shales are decomposed to a great depth, evidencing long sub- aerial action. Three other Terraces occur at heights of 386, 440, and 470 feet, and the latter has, at one place above the village of Cote des Nciges, a beach of sand and gravel with Saxicava and other shells. Even on the top of the Mountain, at a height of about 700 feet, large travelled Laurent ian boulders occur. On the Lower St. Lawrence, below Quebec, the series of Terraces is generally very distinctly marked, and for the most part the lower ones arc cut into the Boulder and Leda clays, which are here of great thickness. I give below rough measurements of the series as they occur at Les Eboulements, Little Mai Bay and Murray Bay, where they are very well displayed. I may remark in general with respect to these Terraces, that the physical conditions at tho time when they were cut must have been much the same with those which exist at present, the appearances presented being very similar to those which would occur were the present beach to be elevated. 1 22 DA W80N— POST-PLIOCENE. TERRACES LOWER ST. LAWRENCE. Ileiyhts in Engli»h/eet, rouijhly taken with Lorke'n f.fffl tiinl Aiieioiil. MM m M\ 'Mi '" I'M 1 LeS £uorLK.MRNTS. rKTiTK Mal Bay. MuRBAY Bay 900 H60 748 479 505 448 378 325 318 312 22(i 239 281 139 116 145 lit) 81 22 26 80 With reference to the differences in the above heights, it is to be observed that the Terraces themselves slope somewhat, and are uneven, and that the principal Terraces are sometimes complicated by minor ones dividing them into little steps. It is thus somewhat difficult to obtain accurate measurements. There seems, however, to be a general agreement of these Terraces, and this I have no doubt will be found to prevail very extensively throughout the Lower St. Lawrence. It will be seen that three of the principal Terraces at Montreal correspond with three of those at Murray Bay ; and the following facts as to other parts of Canada, gleaned from the Reports of the Survey and from my own observations, will serve farther to illustrato this : Kemptville, sand and littoral shells, 250 feet. Winchester, do. 300 " Kenyon, do. 270 " Lochiel, do. 264 & 290 " Hobbes' Falls, Fitzroy, do. 350 " Dulham Mills, DeL'Isle, do. 289 " Upton, 257 " The evidence of sea action on many of these beaches, and the accumulation of shells on others, poik t to a somewhat long resi- dence of the sea at several of the levels, and to the intermittent elevation of tht land. On the wider Terraces, at several levels it is usual to see a deposit of sand and gravel corresponding to the Saxicava sand. >|IM DAWSON— POST-PLIOCENE. 23 In the following table I have endeavoured to represent to the cyo the facts observed in the internal plain of the great Lakes, and in the marginal area of the Atlantic slope, with the mode of accounting for them on the rival theories of glacier ice and floating ice. TABULAR VIEWS OV GLACIAL DEPOSITS AND THEORIES. Facts ohmrved. Theoretical Views. I.NLAND PLAINS. MAKOINAIi AHEA8. OLACIKR THEORIES FLOATING-ICE THEORIES. Terraces. Terraces and raised beaches. Emergence of modern Land. Travelled boulders and glaciated stones and rocks. Strati 1 ed sand and Kravcl. (AlKoma sand, Ac.) Sand and gravel, nth soa shells and boulders. (Saxicava sand). 1 Shallow Seas and Floating Ice. Stratified cloy with drift-wood, and a few stones and boulders. (Erie clay.) Striated rocks. Stratified clay with sea shells. (Leda clay). Clay and boulders with or without soa shells. (Boulder-day). Striated rocks. Deep water with Floating Ice. Submergence of the land. Great continental mantle of Ice. Much floating ice and local glaciers. Submergence of Pliocene land. Old channels, indi- cating a hi^iher level of the land. Old channels indi- cating previous dry land. Erosion by conti- nental glaciers. Erosion by atmos- pberio agencies, & accumulation of decomposed rock. It will be observed that the theoretical views diverge with respect mainly to the Boulder-clay and the striation under the Erie clay, and to the cause of the erosion of valleys in the Pliocene land. I would merely remark, in addition to the considerations already advanced, that the occurrence of drift-wood in the Erie clay, and of sea shells in the Boulder-clay, are both most serious objections to the glacier hypothesis, reserving for the sequel a more full discussion of the rival theories. While the marginal marine area strictly corresponds to the marginal areas of Europe, I have no distinct evidence that the internal plains and table lands of the old continent correspond in their formations to the internal lake area of America. An interesting fact with reference to the Erie clay, stated in the Report of the Survey of Canada is, that these clays bum into III I! I I 24 DAWSON — POST-PLIOCENE. m I i I ' piiilii '- white brick, while the marine Lcda clay burns into red brick. The chemical cause of this I have already referred to, but whether it implies that the inland clays are fresh-water, or only that they have been derived from a different material, is uncertain. The gray clays of the Hudson River series in Western Canada, might, according to Mr. Bell, have afforded such clays. Under the theory of a glacial sea immediately succeeding the elevated Pliocene land, the great amount of decomposed rocks which must have accumulated upon the latter constitutes an im- portant element in the estimation of the rate of deposit of the Erie and Boulder and Leda clays. It is also to be observed that this glacial sea might have had to scour out of the lake basins of Canada only the soft j md of its own deposition, the i-ock-excava- tion having apparently been in great part effected in the previous Pliocene period. On this subject I find that Dr. Sterry Hunt had, before the publication of Dr. Newberry already alluded to,* shown that not only channels but considerable areas about Lakes Erie and St. Clair had been deeply excavated in the palaeozoic rocks and filled with Post-pliocene deposits. The Devonian strata, he remarks, " are found in the region under consideration at depths not only far beneath the water level of the adjacent Lakes Erie and St. Clair, but actually below the horizon of the bottom of these shallow lakes." He shows that around these in various localities the solid rocks are only met with at depths of from one to two hundred feet below the level of the lakes, while "the greatest depth of Lake St. Clair is scarcely thirty feet and that of the South-western half of Lake Erie does not exceed sixty or seventy feet, so that it would seem that these present lake basins have been excavated from the Post-pliocene clays, which, in this region, fill a great ancient basin previously hollowed out of the palaeozoic rocks, and including in its area the South- western part of the peninsula of Ontario." It would thus appear that in the Pliocene period the basin of the lakes may have been a great plain with free drainage to the sea. Whether or not it was afterwards occupied by a glacier, this plain and its channels leading to the ocean were filled with clay at the beginning of the Post-pliocene subsidence ; and at a later date the mud was again swept out from those places where the Arctic current could most powerfully act un it. • On the Geology of South-western Ontario. Am. Jour. Sci. 1868 ■'Br DAWSON — POST-PLIOCENE, 25 PAR T I I. — L C A L I) E T AILS Before entering into the spcciul consideration of this Second Part of the subject, I desire to call attention to some additional facts bearing on two of the most remarkable properties of the Post-pliocei.'^ deposits of the Northern Hemisphere, namely their general similarity of arrangement, and their local diversities. In the first part of this memoir, taking the Post-pliocene of the Lower St. Lawrence as a type, I showed that it has its paral- lel, with but slight general difference, in the wide-spread superficial deposits of the interior of North x\merica surrounding tlie great lakes, and that the Post-pliocene deposits of Scotland and Scan- dinavia almost precisely resemble those of Canada in the general sequence of deposits. Since that part was published, additional illustrations have been afforded by papers in the Geological Maga- zine by Mr. Hull, and Mr. Mackintosh, by papers and discussions on the Eskers of Ireland, at the meeting of the British Associa- tion, and by an able monograph on the Estuary of the Forth, by Mr, David Milne Home. Mr, Hull, who is a " Land Glacia- list," arranges the deposits of the Drift Period in the British area in the following three groups, in descending order, in accordance with Prof Ramsay's observtions in England, and his own in Ireland. 1. Upper Boulder-clay, which he regards as *' generally mar- ine." In Canada, this is represented by the loose boulders and partial boulder deposits of the Upper Saxicava Sand. 2. Shelly marine sands and gravels belonging to the greatest ression of the land, and representini>; our Saxicava Sand and 1868 dep Leda Clay. 3. Lower Boulder-clay, which represents the true or [irincipal Boulder-clay of Canada. This Mr. Hull attributes '• chiefly to land ice." ■ , In Ireland, it would thus soem that the principal sub-divisions of the Post-pliocene can be recognized, and Mr. Kinahan has described the remarkable ridm's of gravel calKd eskers wiiieh run 20 DAWSON — POST-PLIOCENK. across the country in a North-east and South-west dirt'ction. Like our Canadian cskers or " Boar's backs," they are now admitted to be of marine origin, and are attributed to current action and to tlie waves, though floating ice has no doubt, as in Canada, contri- buted in some cases to their formation. Mr. 3Iihie Home gives a grnphic description of the Post-plio- ceno deposits in the neighbourhood of the Fritli of Forth, and many of his numerous sections miglit have just as well lu'en taken from Canadian deposits. He thus sums up the causes of the phe- nomena, assuming that at the beginning of the period the land was submerged. "Tiie ocean over and amund Scotland was full oi' icebergs and shore ice, whicli spread fragments of rocks over the sea bottom and often stranded, ploughing through beds of mud. sand, gravel, and blocks of stone, and miMgling them together in such a way as to form the ' Boulder-clay.' The land thereafter gradually emeriicd. duriuti- which time the lonu' ridges or embankn)ents of gravel called 'kames' were formed." Mr. Mackintosh's observations go mainly to show that in Eng- land, as in Canada, even the lower dril't and rock striation are due to a great extent to floating ice and not to glaciers, and he extends this conclusion even into the lake district oi' England. It is also worthy of I'jmark that the long-received doctrine that glaciers are powerful eroding agents, which the author showed in a paper in this journal, in ISIUJ, to he without foundation, is only now beginning to be discredited in England. I shall rei'er to this in the se((uel, and in the meantime may direct attention to an in- teresting paper on the subject by Mr. Bonney, F.G.S.. in the Journal of the Geological Society for August, 1871. It would further appear that, after the glacial period, in the Post-glacial, the British land rose to a level higher than that which it at present exliibits, then sunk again, and re-emerged in the modern period. Evidences of this later submergence have not been recognized in Canada, but in the inland area they have been detected by Hilgard and by Andrews, Since the publication of the first part of this memoir. Prof. Hilgard has discussed the subject of the southern drifts of the Mississippi valley at the meeting of the American Association at Indianapolis; and I am indebted to that gentleujan and to Prof. Andrev* of Chicago, for much information on these deposits and their relation to those of more northern regions. DAWSOiN — POST-I'MOCENE. 27 ft appears that the oldest Post-plirtcone deposit in the soutli is that called by Prof. Hilgard the '•Orange Sand." This deposit is spread over the States of Mississ-ippi, Alabama, Tennessee, and parts of Louisiana, Kentucky, and Arkansas, and in some places attains an elevation of 700 feet. It contalas water-worn frair- ments of northern rocks, and is supposed by Prof, llilgard to have been deposited by rapid currents of water, possibly fresh, as the deposit contams no uiarine fossils. Above this, accordinj;' to Prof. Ililjiard, is found in places a swamp, lagoon or estuary formation designated the '' Port Hudson group." Succeeding this is the " Bluff or Loess '' group, a deposit of tine silt, liuiited almost or entirely to the Valley of the Missi- sippi. Its maximum thickness is seventy-five feet. On this rests a very widely distributed bed, the " Yellow Loam," not more than twenty feet thick, but much more exten- sively distributed laterally than tlu; former, and reaching an ele- vation of 700 feet. Under the names of "Second Bottoms ttr Hummocks." and " First Bottoms," are known terraced deposits of clay belonging to the present river valleys, but indicating in the case of the Second Bottoms a greater amount of water than at present. It is obvious that all of the above are a([ueous deposits, and there seems to be no evidence whatever in the region referri'd to, of the action of land ice, though the stones and few boulders in the Orange sand arc very probably due to lioating ice. There seems reason to believe that the Orange sand is continuous with the Boulder-drift of the north-west ; and if this is, as stated by Newberry and others, a later deposit than the Erie clay, then it is probable that no representative of the latter exists to the south- west, or that the Orange sand represents the whole of the northern deposits. In any case it ri'presents northern currents of water, though whether salt water admitted by the depression of the land, or fresh water resulting from the melting of ghiciers. it is not easy to decide, as very great difficulties attend cither view in the present state of our knowledge of the deposit. ^Vhat- ever the conditions of deposit of the Orange sand, it would seem to have been succeeded by a land suit',;ee. and this by a depression to the extent of 700 feet or more, before llu; modern elevation oi' the land. If this last elevation corresponds with that of the terraces of the St. Lawrence, then the former one must liave occurred in the St. Lawrence valley in the interval 28 DAWSON — IM)ST-PLIOCENR. m ',:W': Mf m: bcitween the deposit of the Leda chiy and the close of tlie Post- pliocene. This question we shall have occasion to consider in the se(|iu'l. in connection with the second depression of the European land above referred to. Since the publication ol' the first of these papers. Dr. Newberry has kindly sent me a paper of his published as early as 1862, in which he states the remarkable fact, quoted above from his more recent Report on Ohio, th.it the drainaire of the jxreat lake basins, open in Mie e;irly Post-pliocene period, was obstructed by the gla- cial deposits, and has been only partially restored. He also desires me to state that he refers the old drainari((l()i\ In the Journal of the Geological Society of London, for Feb- ruary, 1871, is a communication from Staft-commander Kerr, 11. N., of the Coast Survey, in which he gives the directions of twenty- eight examples of grooved and scratched surfaces observed in the southern part of NewfoutuUand. The cour.se of the majority of these is N.E. a»id S.W.. ranging from N.8" E. to N. 64'' E. The renii.inder are N.W. and S.E..most of them with a predomi- nating Easterly direction. Houlders an- mentioned, but no marine beds. The author refers the glaciation to land ice. supposing certain submerged banks acroiss the m(»uths of the bays to be terminal moraines. The latest information on the Post-pliocene of Labrador is that given in a paper by Dr. Packard in the memoirs of the Boston Society DAWHON — POST-PLIOCKNK. 20 Do of Natural History for 1867. The deposits are said to consist of boulders, Ledu clay and sand, and raised beaches, which, on the authority of Prof. Hind, are stated to reach an elevation of 12(10 feet above the sea. The hills to a hei;j;ht of 2500 feet are roun- ded as if by ice action. Some hij-her hills present a frost-shat- tered surface at their suniuiits. No directions of striae are the Straits of Belle Isle, to- v.i. •/i. 32 DAWSON — POST-PLIOCENK. :!l! I fm n I'L »! Ill the Bay ot Fundy ; and that heavy ice carried by tiiis current would tlien <;;round on Prince Edward Island, or be carried across it to the Southward. If the Laurentian boulders came in this way, their source is probably 400 miles distant in the Strait of Belle Isle. On the North shore of Prince Edward Island, except where occupied by sand dunes, the beach shows great numbers of peb. bles and small boulders ot Laurentian rocks. These arc said by the inhabitants to be cast up by the sea or pushed up by the ice In sprinu;. Whether tliey are now beinu; drifted by ice direct from the Labrador coast, or are old drift beinj; washed up from the bottom of the gulf, which north of the island is very shallow, does not appear. They are all much rounded by the waves, differing in this respiict from the majority of the boulders found inland. The older Boulder-clay of Prince Edward Island, with native boulders, must have been produced under circumstances of power- ful ice-action, in which comparatively little transport of material from a distance occurred. If we attribute this to a glacier, then as Prince Edward Island is merely a slightly raised portion of the bottom of the Gulf of St. Lawrence, this can have been no other than a gigantic mass of ice filling the whole basin of the gulf, and without any slope to give it movement except toward the centre of this great though shallow depression. On the other hand, if we attribute the Boulder-clay to floating ice, it nmst have been produced at a time when numerous heavy bergs were disengaged from what of Labrador was above water, and when this was too thoroughly enveloped in snow and ice to afford many travelled stones. Farther, that this Boulder-clay is a sub- marine and not a subaerial deposit, seems to ^c rendered probable by the circumstance that many of the boulders of sandstone are so soft that they crumble immediately when exposed to the wea- ther and frost. The travelled boulders lying on the surface of the Boulder-clay evidently belong to a later period, when the hills of Labrador and Nova Scotia were above water, though lower than at present, and were sufficiently bare to furnish large supplies of stones to coast ice carried by the tidal currents sweeping up the coast, or by the Arctic current from the North, and deposited on the surface of Prince Edward Island, then a shallow sand-bank. The sands with sea-shells probably belonged to this period, or perhaps to the Iftter part of it, when the land was gradually rismg. Prince DAWSON — POKT-l'LIOCENK. 88 Edwiird Island thus ajijjoars to have reci'ived bouldors from both Hides of the jiulf of St. Jjawrcuco durinu; the hiter Post-pliocene period ; but tiie jireatcr number from the Suutii side, jierhaps be- cause nearer to it. It thus furnishes a remarkable illustration of the tratisport of travelled stones at this period in different directions, and in the comparative absence of travelled .stones in the lower Boulder-clay, it furnishes a similar illustration of the homogeneous and untravelled character of that deposit, in circum- stances where the theory of floating ice serves to account for it, at least as well as that of land-ice, and in my judgment greatly better. 3. Niiirfi tScotiii ((nil Xcir /indisicick. In the.se Provinces the circumstances are entirely different from those in Prince Edward Island, the country consisting of Carboni- ferous and Triassic plains, with ranges of older hills, often meta- morphic, and attaining elevations of 1200 feet or njore. It n)ay, perhaps, be best in the first in.stance to pre.seiit a summary of the phenomena, as I have given them in my Acadian Geology, and to add such additional facts and inferences as the present state of the subject may require. The beds observed may be arranged as follows, in descending order. • ■ 1. Gravel and sand bods, and ancient gravel riduvs and beaches, indicating the action of shallow water, and strong currents and waves. Travelled boulders occur in coimection with the.se beds. 2. Stratified clay with shells, ,'AW.S«»N — I'OST-I'LlorENK. r- '1 «'it ty- , , , t» The followiiij^ are tlu; directions of the diluvitil scratches in :i nuuihcr of localities in different parts of Nova iS(!otia : — point Pleasant and other place,'' near Halifax, exposure south, very dis- tinct stria). ... S. 20'' K. to S. M° K. Head of the U isin, exposure south, K. & W. nearly. S. 20" VV. S. 20^ K. S. 30" K. S. 25" K. but in a valley. hn lEave llivi-r, exposure S.K., Petite River, exposure S. Bear Iliver. exposure X., Rawdon, exposure N., The Gore Mountain, expttsure N., two sets of striio, respectively, . S. tl')" K. & S. 20* E. Windsor Road, exposuro not noted, S.S.K. Gay's Uiver. exposuro N., . Nearly S. & N. Mus((uodoboit Harbour, exposure S., Nearly 8. & N. NearPictou, exposure E., in a valley, Nearly E. & VV. Poison's Jjake, .sununit of a ridj^e, . Nearly N. & S. Near Guysboro', ex[)osure not noted, Nearly S. dt N. Sydney Mines, Cape Breton, expo- sure S S. 30^^ W.* The above instances show a tendency to a Southerly and South- easterly direction, which accords with the prevailing course in most parts of North-eastern America. Local circumstances have, however, modified this prevailiuj^' direction ; and it is interesting; to observe that, while S.E. is the prevailinji' direction in Acadia and New England, it is excer '' in the St. Lawrence valley, where the prevailinj: directio'^ Professor Hind has given a table of similar striat' ,, Brunswick, showing that the direction ranges from W. to N. 30° E., in all except a very few cases. On Blue Mountains, 1650 feet above the sea, it is stated to be N. and S. As in Nova Scotia, N. W. and S. E. seems to be the prevailing course. In a paper published in the Canadian Naturalist, Vu'. VI., No. 1, Mr. Matthew gives a table of striation in the southern part of New Brunswick, in which the South-east direction is decidedly predominant, though there are also some in the South west direction. In this paper will also be found many interesting facts as to the Boulder-clay of NewBruns- * Tlif above courHes are magnetic, tlie averaye variation being about 18° W. . I)AW80N — POST-PLIOCENE. 87 wick, thouf^h the iigency of a continental glacier in invoked to explain some tacts wliich in the sequel we shall find to admit of a different interpretation. The tr.ivelled and untravelled boulders arc usually intermixed in the drift. In some in.stancc8, however, the former appear to be most numerous near the surface of the mass, and their hori- zontal distribution is also very irregular. In examininj.' coast sections of the drift, we may find for some distance a great abun- dance of angular blocks, with few travelled boulders, or both varie- ties are e(jually intermixed, or travelled boulders prevail; and we may often observe particular kinds of these last grouped together, as, for instance, a number of blocks of granite, greenstone, syen- ite, etc., all lying together, as if they had been removed from their original beds and all deposited together at one operation. On the surface of the country where the woods have been removed, this arrangement is sometimes equally evident; thus hundredd of grar.ite boulder,s may be .seen to cumber one limited spot, while in its neighbourhood they are comparatively rare. It is also well known to the farmers in the more rocky districts, that many spots which appear to be covered with boulders have, when these are removed, a layer of soil comparatively free from stones beneath. These appearanci'S may in some instances result from the action of currents of w.itcr, which have in spots carried ofi' the sand or clay, leaving the boulders behind ; but in many cases this is mani- festly the original arrangement of the material, the superficial layer of boulders belonging to a more recent driftage tlian that of the underlying mass in which boulders are often much IcsS abun- dant. Boulders or travelled stones are often found in places where there is no other drift. For example, on bare granite hills, about 500 feet in height, near St. Mary's River, there are large angular blocks of quartzite, derived from the ridges of that material which abound in the district, but which are separated from the hills on whicli the fragments lie by deep valleys. In Nova Scotia I have observed no beds with marine shells^ though the Boulder-clay is often covered with beds of stratified sand and gravel ; and the only evidence of organic life, during the boulder period, or immediately before it, that I have noticed, is a hardened peaty bed which appears under the Boulder-clay on the North-west arm of the River of Inhabitants in Cape Breton. It rests upon gray clay similar to that which underlies peat bogs, f 1 . !■ r 38 DAWSON — PORT-PLIOCENE. Hi, ■' ih I'Mf.'t m and is overlaid by nearly twenty feet of Boulder -clay. Pressure has rendered it nearly as hard as coal, though it is somewhat tougher and more earthy than good coal. It has a shining streak, burns with considerable flame, and appronches in its characters to the brown coals or more imperfect varieties of bituminous coal It contains many small roots and branches, apparently of conifer- ous trees allied to the spruces. The vegetable matter composing this bed must have flourished before the drift was spread over the surface. In New Brunswick, stratified clays holding marine shells have been found overlying the Boulder clay, or in connexion with it, especially in the Southern part of the Province, where deposits of tliis kind occur similar to those found in Canada and in Maine, though apparently on a smaller scale. Those deposits, as they occur iar St. John, consist of gr.'V and reddish clays, holding fossils V ^tL indicate moderately dee\ water, and are, as to species, identical with those occurring in similar deposits in Canada and in Maine. They would indicate a somewhat lower temperature than that of the waters of the Bay of Fundy at present, or about that of the Northern part of the Gulf of St. Lawrence. In Bailey's Report on the Geology of Southern New Brunswick, Professor Hartt has given a list of the fossils of these beds, as seen at Lawlor's Lake, Duck Cove, and St. John, which I re- published with some additions in Acadian Geology. These New Brunswick beds are strictly continuous with, and equivalent to those which extend along the coast of New England, and thence ascend into the Valley of Lake Champlain, while on the other side they may be considered as perfectly representing in character and fossils the Leda clay of Eastern Canada. They are remarkably like both in mineral character and fossils to the Clyde beds of Scotland, which are probably their equivalents. The points of resemblance of the Leda clay of the coast of Maine, and that of the St. Lawrence, and Labrador, were noticed by me in my paper of 1860, already referred to, and have been more fully brought ouc by Dr. Packard, who describes the Leda clay as it occurs at several localities ^ ,m Eastport to Cape Cod. Along this whole coast it retains its Labradoric or Gulf of St. Lawrence aspect, though with the introduction of some more Southern species, and the gradual failure of some more arctic forms. South of Cape Cod, as in the moderL sea, the Post-plio- cene beds assume a much more Southern aspect in their fossils, DA W80N — P08T-PLI0CEN E . 39 the boreal forms altogether disappcarir.g. For a very full exhi- bition of these facts, I may refer to Dr. Packard's paper. The stratified sand and gravel of Nova Scotia rests upon and is newer than the Boulder-olay, and is also newer than the strati- fied marine clays above referred to. Its age is probably that of the Saxicava Sand of the St. Lawrence valley. The former rela- tion may often be seen in coast sections or river banks, and occa- sionally in road cuttings. I ob.served some years ago an instruc- tive illustration of this fact, in a bank on the shore a little to the Eastward of Merigomish harbour. At this place the lower part of the bank consists of clay and sand with angular stones, prin- cipally s.indstones. Upon tliis rests a bed of fine sand and small rounded gravel with layers of coarser pebbles. The gravel is separated from the drift below by a layer of the same sort of an- gular stones that appear in the drift, showing that the currents which deposited the upper bed have washed away some of the finer portions of the drift before the sand and gravel were thrown down. In this section, as well as in most others that I have ex- amined, the lower part of the stratified gravel is finer than the upper part, and cont;iins more sand. In some cases we can trace the pebbles of the gravels to ancient conglomerate rocks which have furnished them by their decay; but in other instances the pebbles may have been rounded by the waters that deposited them in their present place. In places, however, where old pebble rocks do not occur, we sometimes find, instead of gravel, beds of tine laminated sand. A very remark- abli! instance of the connexion of superficial gravels with ancient pebble rocks occurs in the county of Pictou. In the coal forma- tion of this county there occurs a very thick bed of conglomerate, the outcrop of which, owing to its comparative hardness and great mass, forms a high ridge extending 'Vom the hill behind New Glasgow across the East and Middle Rivers, and along the South of the West River, and then, crossing the West River, re-appears in Rogers' Hill. Ti»e valleys of these three rivers have beea cut through this bed, and the material thus removed has been heaped up in hillocks and beds of gravel, along the banks of the streams, on the side toward which the water now flows, which happens to be the North and North-east. Accordingly, along the course of the Albion 1 lines Railway and the lower parts of the Middle and West Rivers, these gravel beds a.e everywhere exposed in the road-cuttings, and may in some places be seen to rest on f 40 DAWSON — POST-PLIOCENE. n ir i the Boulderclay, showing that the cutting of these valleys was completed after the drift was produced. Similar instances of the connexion of gravel with conglomerate occur near Antigonish, and on the sides of the Cobociuid mountains, where some of the val- leys have at their Southern entrances immense tongues of gravel extending out into the plain, as if currents of enormous volume had swept through them from North to South. The stratified gravels do not, like the older drift, form a con- ♦^inuous sheet spreading over the surface. They occur in mounds and long ridges, or eskers, sometimes extending for miles over the country. One of the most remarkable of these ridgos is the "Boar's Back," which runs along the West side of the Hebert River in Cumberland. It is a narrow ridge, peHiiips from ten to twenty feet in height, and cut across in several places by the chaimels of small brooks. The ground on either side appears low and flat. For eight miles it forms a natural road, rough in- deed, but practicable with care to a carriage, the general direction being nearly North and South. What its extent or course may be beyond the points where the road enters on and leaves it, I do not know ; but it appears to extend from the base of the Cobe- quid mountains to a ridge of sandstone that crosses the lower part of the Hebert river. It consists of gravel and sand, whether stratified or not I could not ascertain, with a few large boulders. Another very singular ridge of this kind is that running along the West side of Clyde river in Shelburue county. This ridge is higher than that on Hebert river, but, like it, extends parallel to the river, and forms a natural road, improved by art in such a manner as to be a very tolerable highway. Along a great part of its course it is separated from the river by a low alluvial flat, and on the laud side a swamp intervenes between it and the higher ground. Shorter and more interrupted ridges of this kind may also be seen in the country Northward and Ea' /ard of tiie town of Pictou. In sections they are seen to be stratified, and they generally occur on low or level tracts, and in places where if the country were submerged, the surf or marine currejits and tides might be expected to throw up ridges. The presence of boulders shows that ice grounded on these ridges, and it, probably by its pressure, in some instances, modified their forms. These eskers, or " horse-backs," must not, however, be confounded with glacier moraines, to which in structure they bear no resemblance what- ever. DAWSON — POST-PhlOCKNE. 41 It is probably to this more modern part of the Post-plioceue, if not to a more recent lieriod followini; th(! elevation ol" tlu- l:intl, that the bones of the mastodon found in Cape liretoii, .ind dis- cribed in •' Acadian Geolotry," belt)n<;. For many additional facts relatiui;' to the Post-pliocone <>i Niiw Brunswick, I may refer to the valuable paper by Mr. M ittlnu, already mentioned. ■<> 4. Loirrr St. Liiirrcncc — \orth Si ;f Id K- 1 42 UAWSON — POST-PLIOCENE. '•• 1 1;. ii= expedition Koon to be publisliod by Dr. Petennanti, will jro far to re- move the prevailing error as* to Greenland being covered wl.h a universal glacier ; whereas it seems to be a rocky and mostly snow-clad country, with very large glaciers in its valleys. The strikes of the gneiss on the opposite sides of the Sagucnay indicate tuat it occupies a line of transverse fracture, constituting a weak portion of the Laurentian ridges, and this has evidently been smoothed and deepened by water and ice under conditions different from the pres^ent, in which it is jirobable that the chan- nel is being gradually Piled witli mud. Its excavation must have taken place before tlu; deposition of the thick beds of marine clay (Leda clay) which appcjir near its mouth and in its tribu- taries, sometimes passing into Boulder-clay below, and cajiped by sand and gravel. It is indeed not improbable that in the later Post-pliocene i* was in great part filled up with such deposits, which have been swept away in the course of the re-elevation of the land. At Tadous.sac, a\ the mouth of the Sagucnay, where the under- lying formation is the Laurentian gneiss, the Post-pliocene beds attain to great thickness, but are of simple structure and slightly fossiliferous. The principal part is a stratified sandy clay with few boulders, except in places near the ridg»!s of Laurentian rocks, when it becomes filled with numerous rounded blocks and pebbles of gneiss. This forms high banks eastward of Tadoussac. It contains a few shells of Tvlllnd Otra'nlKudU-H and Leda trmicata, and a little inland, at Bergeron Kiver, it also contains Cnnlimn Islandicum, Antitrtc ellqtticti, and Rhi/iichoiiclla paittaccAi,. It resembles some of the beds seen on the South side of the river St. Lawrence, and has also much of the aspect of the Leda clay, as developed in the valley of the Ottawa. On this clay there rest in places thick beds of yellow sand and gravel. At Tadoussac these deposits have been cut into a succession of terraces which are well seen near the hotel and old church. The lowest, near the shore, is about ten feet high ; the second, on which the hotel stands, is forty feet; the third is 120 to 150 feet in height, and is uneven at top. The highest, which consists of sand and gravel, is about 250 feet in height. Above this the ■country inland consists of bare Laurentian rocks. The.se terraces have been cut out of deposits, once more extensive, in the process -of elevation of the land ; and the present flats off the mouth of the Sagucnay, would form a similar terrace as wide as any of the -others, if the country were to experience another elevatory move- DAWSON — POST-PLIOCENE. 43 nient. On the third terrace I observed a lew hiri^e Ijaurenthiu boulders, and some [tieces of red and <>riiy shale of the Quebec group, indicating- the action of coast-ice when this terrace was cut. On the hiuhest terrace there were al.so a few boulders; and both terraces are capped with pebbly sand and well rounded <;ravel, indicating tlic long-continued action of the waves at the levels which they represent, Mtirray Bre-du-Loup indubitable evidence of a marine Boulder-clay, and this underlies the representative of the Leda clay, and rests immediately on striated rock surfaces — the striaD running north-east and south-west. The Cacouna Boulder-clay is a somewhat deep-water deposit. Its most abundant shells are Leda truncata, Nucula temtis, and Tellina proximo, and these are imbedded in the clay with the valves closed, and in as perfect condition as if the animals still inhabited them. At the time when they lived, the Cacouna ridges must have been reefs in a deep sea. Even Mount Pilote has huge Laurentian boulders high up on its sides, in evidence • Canadian Naturalist, April, 1866. DAWSON — POST-PLIOCENE. 51 of this. The .slialt'H of the Quebec f,'roup were being wnsted by the waves and currents ; and while there is evidence that much of tlic fine mud worn from them was drifted far to the south- west to form the chiy.s of tlie Canadian phiins, otiier portions were deposited between the ridges, along with boulders dropped from the ice which drifted from the Laurcntian shore to the north. The process was slow and quiet ; so much so that in its later stages many of the boulders became encrusted with the cal- careous cells of marine animals before they became buried in the clay. No other explanation can, I believe, be given of this de- posit; and it presents a clear and convincing illustration, applic- able to wide areas in Eastern America, of the mode of depo.>! Gray and reddish clay 9 Hard buff sand, very tine and laminated 15 Sand with layers of ton^h clay, holding glaciated stones, and very irregularly disposed 4 Fine sand . . , , 1 Gray sand, with rounded pebbles, and laminated ob- scurely and diagonally 4 Fine laminated yellow sand 3 Gravel 4 Very irregular mass of laminated sand, with mud, gravel, stones and largo boulders 12 50 10 The whole of these (lepo.sits except the Leda clay, are very irregularly bedded, and are apparently of a littoral character. They seem to shew the action of ice in shallow water before the deposition of the Leda clay. The only way of avoiding this conclusion would be to suppose that the underlying beds are really of the age of the Saxicava sand, and that the Leda clay has been plao'' above them by slipping fram a higher terrace ; but I failed to see good evidence of this. A little farther west at the gravel pits dug in the terrace for railway ballast, a deep section is exposed showing at the top Saxicava sand, and below this a very thick bed of sandy clay with stones and boulders,'con- stituting apparently a somewhat arenaceous and partially stratified equivalent of the Boulder-clay. A little above this place, at the Brick-works, the Saxicava sand is seen to rest on a highly fossil- iferous Leda clay, which probably here intervenes between the two beds seen in contact nearer the edge of the terrace. Ottawa River. — The Leda clay and Saxicava sand are well exposed ou the banks of the Ottawa; and Green's Creek, a little below Ottawa City, has become celebrated for the occurrence of hard calcareous nodules in tlie clay, containing not only the ordinary shells of this deposit, but also well-preserved skeletons of the Capelin (iVjJIotns') of the Lump-sucker (JJycloptcrus) and of a species of stickleback (Gastcrostcus). Some of these nodules also contain leaves of land plants and fragments of wood, and a fresh-water shell of the genus Lymnca has also been found. 58 DAWSON — POST-PLIOCENE. ' At Packeoham Mills west of the Ottawa, the late Sheriff Dickson found several species of land and fresh-water shells associated with Tellina Groenlandica and apparently in the Saxicava sand. These facts evidence the vicinity of the Laurentian shore, and indicate a climate only a little more rigorous than that of Central Canada at present. They were noticed in some detail in my paper of 1866 in The Canadian Naturalist.. The marine dc^'^sits on the St. Lawrence are limited, as already stated, to the c itry east of Kingston; and the clays of the basin of the great lakes to the south-westward have, as yet, afforded no marine fossils. I have, however, just learned from Prof Bell, of the Geological Survey, a discovery made by him in the past summer and which is of very great interest, namely that two hundred miles north of Lake Superior the marine deposits reappear. The details of this important discovery will be given in a forthcoming Report of the Geological Survey, and its theoretical significance will be referred to in the conclud- ing part of this memoir. In the above local details, I have given merely the facts of greatest importance, and may refer for many subordinate points to the papers catalogued in the introduction to this memoir, and to the reports of the Geological Survey of Canada, DAWSON — POST-PLIOCENE. 59 PART 111.— REVISION OF POST-PLIOCENE FOSSILS OF CANADA. The list of Post-pliocene fossils published previously to 1856, amounted to only about 2(3 species. In my papers published between that year and 18G.3, the number was raised to nearly 80. My lists were tabulated, along with some additional species fur- nished in MS, in the Report of the Geological Survey for 18G3, the list there given amounting to 8.S species, exclusive of Fora- minifcra. In my paper on the Post-pliocene of Riviere-du-Loup and Tadoussac, published in 18G5, I added 38 species, and shall be able still farther to increase the number in the present revision, which will afford a very complete view of the subject up to the present time ; and though additional species will no doubt be found, yet all the principal deposits have been so carefully ex- plored that only very rare species can have escaped observation. For some of the additional species included in the present list, I am indebted to Mr. G. T. Kennedy of Montreal, Dr. Anderson of Quebec, and other friends, to whom reference will be made in connection with the several species in the catalogue. SUB-KINGDOM RADIATA, Class I. — Protozoa. (1) Foraminifera. -i' Nodosaria (Glandidina) laevigata. ■(Var. DeMalina communis) Fossil — Leda clay, Montreal. Recent— Gulf St. Ijawrence, 30 to 300 fathoms, G.M.D.* This species is very rare in the Post-pliocene, but sometimes of large size and of different varietal forms. * The initials G. M. D., refer to the List of Foraminifera by Mr. G. M. Dawson iu The Canadian Naturalist, 1870. I 60 DAWSON — POST-PLIOCENE. I If! "i- Lagena iSulcata i|l!?!.4 111' ■• ;.f' ■ ■ ' '«■■', (Var. dlntoma.) (Var. semisulcafa.) Fossil — Leda clay, Montreal; Quebec; Murray Bay; Rivi^re- (lu-Loup; Portland (Maine.) Recent— Gulf St. Lawrence, 18 to 313 fathoms, G.M.D. Rather rare iu the Post-pliocono as well as in the recent. ^ Entosolenia globosa. costata. marginata. squamosa. Fossil — Montreal, Leda clay ; Labrador ; Rivi»^re-du-Loup ; Murray Bay; Quebec; Portland (Maine). Recent — Gulf and River St. Lawrence, 20 to 313 fathoms. G. M. D. Generally diffused in the Post-pliocene, and presenting the same range of forms as in the recent ; but not common. I regard the supposed species of Entosolenia above named as merely varietal forms. Bnllniina Prcsli. ill' I (Var. squamosa) Fossil — Montreal, Leda clay; Labrador; Riviere-du-Loup^ Murray Bay; Quebec; Portland (Maine). Recent — Gulf and River St. Lawrence, 10 to 313 fathoms, G. M. D. Generally diffused in the Post- pliocene. In the recent it seems to be a deep-water form. What Parker and Jones call the essen- tially arctic form B. elegant issima is not uncommon, though other forms also occur. Polyniorphina lactea. Fossil — Montreal, Leda clay ; Labrador ; Riviere-du-Loup ; Murray Bay. Recent — Gulf and River St. Lawrence, 30 to 313 fathoms. G. M. D. Not uncommon in the Post pliocene, particularly in the deeper parts of the Leda clay. Less common recent. I observed in the Riviere-du-Loup gatherings a small individual of this species with the internal pipe at the aperture characteristic of Entosolenia, which ia also sometimes observed in recent specimens. DAWSON — POST-PLIOCENE. TruncatiUina lobulata. 61 Fossil — Ledii clay, Labrador ; Rivierc-du-Loup. Recent — Gulf St. Lawrence, very common 30 to 50 fathoms. This species is much less common in the Post-pliocene than in the recent. Orhulina univcrsa. Fossil — Ledu clay, Montreal ; Rivicre-du-Loup ; Labrador. This may be regarded as a rare and somewhat doubtful Post- pliocone fossil. It has not yet been recognized in the Gulf of St. Lawrence. Glohxgenna huUoidcs. Fossil — Riviere-du-Loup. Recent — Gulf St. Lawrence, more especially in the deeper water, where it is common. It is very rare in the Post-pliocene. Puloinulina repanda. Fossil — iSIontrcal, Lcda clay; Ririere-du-Loup; Murray Bay; Labrador; Quebec; Portland (Maine). Recent— Gulf St. Lawrence, 30 to 313 fathoms, G. M. D. Somewhat rare both in the Post-pliocene and recent, and of the small size usual in the arctic seas. PohjStomcJla crispa. — (Var. Siriatopunctata). (Var. Arctica.) Fossil — Montreal, Lcd;i clay ; Labrador; Riviore-du-Loup ; Murray B.iy; Quebec; Portliiid (Maine); St. John, N. B. Recent — Gulf and River St. Lawrence, 30 to 40 fathoms. G. M.D. Very common, especially in depths of 10 to 40 f itlioms. This is by far the most abundant species in the Post-pliocene deposit.s, as it is also in all the shallow p;irts of the Gulf of St. Lawrence at present, and also in the Arctic Se.is, according to Parker and Jones. It is the only species yet found in the Boulder-clay of Montreal, and this very rarely. Nonioniua scaplia. (Var. Lalradorica.') Fossil — Ledii cliy, Montreal ; Rivierc-du-Loup; Labrador; Murray Bay ; Quebec ; St. John, N. B. 9 e2 DAW£ON — rOST-PLIOCENE. •■I- r I- Recent — Gulf and River St. Liwrence, 10 to 313 fathoms. Vnr. Labradorica is the deeper water form and is rare iu tho Leda clay, , Textulariu pi/gmctti. Fossil — Leda clay, Labrador ; Rivi6rc-du-liOup ; Quebec ; also at Portland (3Iiiine). Recent— Gulf St. Lawrence, 10 to 30 fathomy. The Tcxtulirioo are rare and of small size, botis. in the Post- pliocene and recent. n Cornuspira foUacca. Fossil — Leda clay, Montreal. Recent— Gulf St. Lawrence, 10 to 250 fathoms, G. M. D. "! This species is rare both fossil and recent. Quinqueloculina seminidum. Fossil — Leda clay, Montreal ; Labrador ; Quebec ; Portland (Maine). Recent — Gulf St. Lawrence, 10 to 313 fathoms, most abun- dant in shallow water. G. M. D. This species is by no means common and not usually larpje in the Post-pliocene. It is more abundant in the clays of Maine than in those of Canada. i' Bilocullna ruigevs. Fossil — Leda clay, Montreal ; Labrador ; Riviere-du-Loup ; Murray B;iy ; Quebec. Recent— Gulf St. Lawrence, 30 to 313 fathoms. G. M. D. Rather rare in the Post-pliocene as well as in the recent. ii Tr'docuUna tricarinata. Fossil — Leda cl;iy. Rivieredu-Loup; Murray Bay; Quebec. Recent- Gaspe, 30 to 50 fathoms. G. M. D. Rare both in Post-pliocene and recent, but perhaps more gen- erally diffused in the former. Litnola and Saccammina. A very few minute sandy forms referable to these j^encra arc found among the finer part of the washings from Riviure-du-Loup. EugJypha ? A single minute test, apparently identical in form with that of EugJypha alveolata, was found in washing the Riviore-du-Loup clays. l^AWSON — POST-PLIOCENE. 63 In general terms it raay bo stated that all the species of For- nminifera found in the Post-plioccno still inhabit the Gulf and River St. Lawrence. Several species found in the Gulf of St. Lawrence have not yet been recognized in the Post-plioccnc, and these are mostly inhabitants of depths exceeding 90 fathoms, or among the more southern forms found in the Gulf. On the whole, the assemblage, as in the northern part of the Gulf of St. Lawrence at present, is essentially arctic, and not indicative of very great depths. The sandy forms which are not uncommon in thd Gulf arc very rare in the Post-plioccnc ; but this may be accounted for by the greater difficulty of washing them out of the clay, or possibly their cementing material may have decomposed, allowing them to full to pieces. As the epidermal matter of shells is often pre- served, the last supposition seems less likely. The Leda clays arc, however usually very fine and calcareous, so that there was probably more material for calcareous than for arenaceous forms. The Foraminifera are very generally diffused in the Po.st plio- cene clays, though much more abundant in some liyers than In others. They may easily be detected by a pocket lens, and :ire usually in as fine preservation as recent specimens, especially in the deeper and more tenacious layers of the Leda clay. They are however, usually most abundant in the somewhat arenaceous layers near the top of the Leda ch.y, and immediately below the Saxicava sand, and especially where this layer contains abund- ance of shells of Mollusca. I have nowhere found them more abundant or in greater variety than at the Glen Brick-work, Montreal, on the MeGill College Grounds^ and at Lognn's Farm. At the Glen Brick-work a few worn specimens of Poly- Btomella are contained in the beds underlying the Leda clay and equivalent to the Boulder-clay, which, however, has in general, in the vicinity of Montreal as yet afforded no marine fossils. In searching for Foraminifera in the clays of Riviorc-du-Loup, I have observed in the finer washings several species of Diato- maccaj ; among these a species of Coscinodlscus very frequent ia the deeper parts of the Gulf of St. Lawrence. But on the whole Diatoms appear to be rare in these depositt;. In the Riviere-du- Loup clays I have also observed the pollen grains of firs and spruces. The nomenclature used above is that of Parker and Jones, in their paper on the North Atlantic Soundings, in the Transactions m U t II if . i ^: :: ii' m " 64 DAWSON— POST-PLIOCENE. of the lloyal Society. For fit^urcs of the species, I iiiny refer to that memoir, unJ to my previou" papcr.s published iu the Natur- alist. (2) For if cm. Tethea Logan i, Dawson. Leda clay, Montreal. This species has not yet been rceoi^nised in n livinir state, though allied to Tithca In'sjiida, Bowerbaiik, of the coast of Maine. Its spicules in considerable mtisses, look- ing like white fibres, are not uncommon in the Post-pliocene at Montreal. Tefhea ? Another silicious sponge is indicated by little groups of small f^picules found at the Tanneries, near iMontreal, by Mr. G. T. Keimedy, and at Riviere-du-Loup by the author. Its spicules are long and acerate, and much njore slender than those of Tethea Logani, They resemble thos-c of T. hispida, recent on the coast of Maine, and also those of a species of Pufi/mastia, dredged by Mr. Whiteuves in the Gulf of St. Lawrence. Class II. — Antiiozoa. Olass III. — Hydrozoa. No distinct organisms referable to the above groups have yet been found in the Post-pliocene deposits of Canada. As our recent fauna includes no stony coral, and the recent species of the Gulf of St. Lawrence have no parts likely to be ])reserved other than minute spicule,"*, this is not to be wondered at. In washini' the clays for Foramiiiifera, however, numerous fratrraents are obtained, whicli resemble portions of the horny skeletons of hydroids, though not in a state admitting of determination. ; ,, Class IV. — Echinodermata. . * •';..' (1) Ophiuridea. '. ,,; Ophiogh/pha Sarsii, Lutken. Fossil — Led I clay, near St. John, N. Brunswick ; Mr. Matthew. Recent — River St. L;iwrcnce, at Murray Biy; alt^o found of large size in deep water iu the Gulf of St. Lawrence, by ^Ir. Whiteaves. DAWSON — POST-PLIOCENE. 65 Ophiocomn . Fraguieiits of a small species of ophiuroid starfish not doter- iniiiablc, have been found in the l^edu clay at Montreal, and in nodules at (Jrecn's creek. (2) Echlnoiiha. fJurt/echvim drnhnchiensist, Miiller. Fossil — Leda clay, Beauport ; llivic^rc-du-Loup ; Montreal. This spcci(!8 is rare in the Post-pliocene, but vefy common in all parts ol" tlio Gulf of St. Lawrence at present. (3) Iloluthuridea. Psotufi 2>hant >• us ? Okeu. Scales of an animal of this kind have been found in the Leda clay at Montreal. They may belong to /*. phantopns, or to the species P. (Loj}ltothuria) Fabricii, also found on our coaats. SUB-KINGDOM MOLLUSCA. Introductori/. — In preparing this, the largest and most impor- tant part of my catalogue, I have to acknowledge my obligations to Dr. P. P. Carpenter, for his kind aid in comparing all the more critical species of shells, and in giving me his valuable judgment as to their relations and synonymy, which I have in nearly every case accepted as final. I am also indebted to Dr. Carpenter for all the notices of West-coast shells. To Mr. J. F. Whiteaves, F.G.S., I am indebted for reviewuigthe Polyzoa and conjparing them with Smitt's Norwegian catalogues, and also for many valuable facts as to shells obtained in his recent dredgings in the Gulf of St. Lawrence. ToMr.J.Gwyn Jeffreys,F.R,S.,and Mr. R. McAndrew, F.R.S., of London, my grateful acknowledgments are due for aid and information, and also for the opportunity of comparing my .speci- mens with those in their collections. My comparisons with recent species have been made to a great extent with specimens dredged by myself, iu the Gulf of St. Lawrence, and especially at Murray Bay, where the marine fauna seems to be more nearly related to that of the Post-pliocene »J 4' I- Sfc;i I' r I 8' . I 5 p:. GG DAWSON — POST-PLIOCENE. thaa in any part of the Gulf of St. Lawrence with which I am acquainted. I have also to acknowledge the use of specimens fron) Greenland, from Prof. Morcii ; from Norway from Mr. McAndrew; from Nova Scotia from Mr. Willis; as well as the use of the large and valuable collections of Dr. Carpenter and Mr. Whiteaves. All the references in the following pages, except where authors arc ({uotod, and many of these last, have been verified by myself by actual comparison of specimens. T.'ie principal works to which I have referred in the publica- tion of the catalogue are the following : Beechey's Voyage, Natural History Appendix. Belcher's Last of the Arctic Voyages, do. Bell, Report on luvertebrata of Gulf of St. Lawrence. Busk, Polyzoa ol' the Crag. Crosskey on Post-pliocene of Scotland. Fab'icius, Fauna Gra'nlandica. Forbes and Hauley, British MoUusca. Gould, Invertebrata of Massachusetts, edited by Binney. Jeffreys' British Conchology. Lyell on Shells collected by Capt. Bayfield ; and Travels in North America. Matthew on Post-pliocene of New Brunswick. Middendorfi", Shells of Siberia. Pack.ird on the Glacial Phenomena of Labrador and Maine. Prestwich on the English Crag. Sars on the Quaternary of Norway. Stimpson, Shells of Hayes' Expedition, &c. Whiteaves, ListsofShellsfrom Gulf of St. Lawrence, Canadian Naturalist. Wood, Crag Mollusca. Willis, Lists of Shells of Nova Scotia. 1 J jfii -' I .* ? Class L — Hetkrohranceiiata. Sub-Class I. — Volyzoa. Hij>pothoa catevnhtria, Jameson. Fossil — Beauport ; Labrador ; Riviere-du-Louf . Recent — Gaspe*; Labrador (Packard). * 'I'lic icIrn.'iK rs t(j (Jaspc jiic I'loni my list (ontribii^ed to tlie Kept. GeoL Suivcy, ISHS — Ikll fiinl HicJiaidsoii, collcctois ; and from subse- quent clredgiugs by niynjlf and Mr Wiiiteavcs. DAWSON — POST-PLIOCENE. 67 Ilippotlwa expansa, Dawson. Fossil — Bcauport ; llivi«ire-du-Loup. Kecent — Gaspo ; Labrt lor, Maine (Packard). Tuhidipora Jlahellaris, Johnston. Fossil — Beauport ; Rivii^redu-Loup. Recent — Gaspe, Labrador (Packard) (= T. j^nhnrita, Wood). Lepralla hj/alino, Johnston. lossil — Beauport; Riviere-du-Loup. Recent — Gaspe. Lrpral'ui pcrtusa, Thomson. Fc^sil — Beauport ; Labrador ; Riviere-du-Loup. Recent — Gaspe, Labrador (Packard). Lcpralia quadricornuta, Dawson. Fossil — Leda clay, Montreal. Not yet found recent. Mr. T. Curry, of Montreal, has recently found specimens ir a very perfect state. They show that the cells are sculptured in a papillo-striate manner, and that the ovi-capsules are globular and granulate. Some cells have a projection for a vibraculum or avicularium at one side of the aperture. A few have two of these. Old colonies have a pitted calcareous deposit between the cells. The large size and naruw aperture with deep sulcas iu front and four spines behind are as in the specimens formerly described. Lepralia sjmiifera^ Busk. Fossil — Riviere-du-Loup. L. violacea f Johnston. Fossil — Riviere-du-Loup. It wants the depression in front of the cell said to be charac- teristic of the .species. (J. I . Whiteaves.) //. variolosa, Johnston. Fossil — Riviere-du-Loup. Recent — Gaspe. Dr. Smitt unites this with L. trispinoia of Johnstoti, and con- siders both as varieties of L. Jacotini, Audouin L. Jacotinij Gray, is a very diflFerent species. (J. F. W. Lepralia Belli, Dawson. Fossil — Rivi<^re-du-Loup. Becent — Gaspe ; Labrador (Packard). J. 9: 1 I % 68 DAWSON — POST-PLIOCENE. L. 2irnducta,Vackavd. Fossil — Rivitirc-du-Loup. Recent — Labrador (Packard) ; Gasp^ ; Murray Bay. L. glohifem, Packard. Fossil — Riviere- du-Loup. Recent — Labrador (Packard). L. punctata "^ Hassall. Fossil — Riviere-du-Loup, lleccnt — Gaspe. Tlie oral spines of this species cannot be made out in the fossil specimens I have seen. Smitt refers Hassall's species to D'Or- bigny's sub-genus Escharlponi. (J. F. W.) L. PeacMi, Johnston. Fossil — Riviere du-Loup. Recent — Gaspd. Rare in the Gulf of St. Lawrence. Smitt groups this species, ' together with L. variolosa (of Busk but not of Johnston) and L. vcatricosa, as forms of Diacopora coccinea. (.1. F. W.) LepraUa trisjiinosa, Johnston. Fossil — Riviere-du-Loup. Recent — Gaspe; Labrador (Packard). Lepralia veiitrlcosa, Hassall. Fossil — Riviere-du-Loup. Recent — Gulf St. Lawrence. Dotstopora ohclia, Johnston. Fossil — Riviere-du-Loup. Recent — Gaspe. Eschara eleyantuhi, D'Orbigny. l^isHil— Riviero-du-Loup; Montreal (Curry). Recent— Labrador (Packard) ; Gasp<5. Very fine and frequent in 10-30 f lihoms opposite Cape Ro- sier Village. More abundant iu the open river than in Gasp6 and other bays. (J. F. W.) C(dhporana surcularls, Packard. Fossil~Rivierc-du-Loup. Recent— Labrador (Packard) ; Gaspd. Smitt identifies this species with the C. incrassafa of Lamarck. Abundant in 10-50 fathoms everywhere in the Gulf, and often drifted down to lower levels. (J. F. W.) DAWSON — POST-PLIOCKNE. 01) Mi/riozouin suh-grarile, D'Orbigiiy. Fossil — Rivi(>re-(lu-Loup. Recent — Labrador (Packard) ; Gae-pe. Idmonea athintiat, Forbes, Fossil — Riviere-du-Loup. Recent — I believe this to be idouticul with a spocies found in the Gulf of St. Lawrence, and referred by Dr. Packard and Mr. Whiteaves to th*. above. Criaia eburnea, Ellis. Fossil — Montreal. A specimen collected by Mr. Curry is referred to this species by Mr, Whiteaves. Recent — Librador (Packard). In 96 fathoms, Trinity Bay, N. Shore St. Lawrence R, J. F. W, Ahcto, sp. Fossil — Rivi«ire-du-Loup, MembfvJpora Lacroirii, Busk. Fossil — Rivieredu-Loup, Recent — Gasp^ ; Labrador (Packard), Entirely agrees with recent examples from Gulf of St. Law- rence. One of the six forms referred by Smitt to M. lincata Linn. (J. F. W.) Memhranipora lincata^ Linn. Fossil — Rivi^re-du-Loup. Recent — Gasp^. Discoporella hispida, Johnston. Fossil — Rivi^re-du-Loup. Patches on shells, somewhat worn, but referable to this common North Atlantic species. Sub- Class II. — Brachiopoda. Rhynchonclla j)sittacea, Gm. Fossil — Montreal; Beauport; Rivi6rc-du-Loup. Abundant. Recent — Murray Bay and Gaspd. Abundant. Labrador (Packard) ; Gulf St. Lawrence. Generally on stony bottoms 10 fathoms and over. Arctic seas generally ; also Crag of England and glacial beds. In a bed of stony clay at Rivitfredu-Loup, this shell is very abundant, with less abundant specimens of the next species. It occurs living in precisely the same relations and in groat abund- ance at Murray Biy, in about 20 fathoms, . 70 DAW80N — F'OST-PLinCENE. i!« 1; ..iF Terehratdlii Spitzhergensls, Davidsou. Fossil — Kivi^re-du-Loup. Recent — Murray Bay ; also deeper parts of Gulf of St. Law- rence (Whitcaves) ; Nova Scotia (Willis). This species has been found in the Post-pliocene of Canada, liitherto only at Riviere- du-Loup, and is rare. It was called 7\ Lahradorensix, Sowerby, in former lists, which seems to be a synonym. It appears to bo a rare shell in every part of the Gulf where it has hitherto occurred, except at Murray Bay, Avhere it is not uncommon, and is Ibund attached to stones in 20 to 25 fathoms, associated with Rhipwhonella psittacea. Class II. — Lamelliuranciiiata. P/ioJas (^Zir/)hea) crispata, Linn. Fossil — M line (Packard). I have nol found this species fossil in Canada, but it exists as a living shell on the Now England coast generally, in North- umberland Strait ; Gulf of St. Lawrence, and according to Bell as far to the north-west as Rimouski. Puget Sound (U. S. Expl. Exped.) It has perhaps extended its northern limit to Canada since the glacial period. On the European coast it is a northern shell, reaching south to the Mediterranean. Saxicava riujosa, Linn (and var. Arctmi). Fossil — Saxicava sand and top of Leda clay, Montreal ; St. Ni- cholas ; Ottawa ; Quebec ; Murray Bay ; Rivit>re-du-Loup ; Trois Pistoles ; Tadousac ; Labrador ; Lawlor's Lake, New Brunswick ; Maine, &c. Recent — Gulf St. Lawrence ; coast of Nova Scotia ; and Now England and northern seas generally ; also west coast of America as far as Mazatlan. (P. P. Carpenter). Very abundant in the more shallow portions of the Post-plio- cene throughout Canada, and presenting all the numerous varie- tal forms ol' the species in great perfection. It is relatively much more abundant in the drift deposits than in the Gulf of St. Lawrence at present. Pieces of limestone which have been bored probably by this shell, are not rare in the drift at Mont- real. This is a widely distributed Arctic species, and is found in the Post-pliocene deposits of Europe, and as far back as the Miocene. I J.L "Vf DAWSON — I'OST-PLIOOKNE. 71 I Panopcea N'orveyica, Spongier. Fossil — Leda clay ; Kivicrc-du-Loup. Very rare. Recent — Dredged in Gaspe Bay, 30 and 40 fathoms, by Mr. Whiteaves ; Halifax (Willis) ; Grand RIanan (Stiuipsou) ; Arctic and northern seas generally. It is very rare in the Post-plioccoe, a few valves only having been found at Riviere-du-Loup. The specimens are small, and much inferior to those found in the Scottish (Myde beds, of which I have a specimen from Rev. H. Crosskey. Afi/a truHcaf.a, Linn, (and var. IkOfrvitllctms). Fossil — Saxicava sand and Leda clay ; Montreal ; Quebe(? ; Riviere-du-Loup ; Portland ; New Brunswick (Matthew) ; La- brador (Packard); Greenland (MoUer) ; also in the Post-pliocene of Europe. Recent — Gulf St. Lawrence, but rare in comparison with its abundance in the drift. Generally distributed in the Arctic seas and North Atlantic, American coast as far south as Cape Cod ; Puget Sound (. prfdos'i, Gould, ]». P. C.) The variety found in the Post plioccue of Canada is the short or iJddfvalletisls variety, which is that occurring in the Arctic seas at present, while in the Gulf kit. Ijawrence the ordinary long- variety is found almost exclusively. At Portland, Maine, how- ever, the long variety lived in the Post-pliocene, and occasional specimens are found at Riviere-du-Loup. The form Ihlikvall- eiisis occurs living in Labrador (Packard), and I have found it at Tadousac. It is interesting to observe that while the present species is more abundant than the next in the Post-pliocene, it is much more rare in the Gulf at present. It also occurs in deeper water. M'ja arena ria, Linn. Fossil — Leda clay and lower part of Saxicava sand ; Montreal; Upton; Quebec; Murray Bay; Labrador; Duck cove and Law- lor'slake. New Brunswick ; Portland, Maine; Greenland (Mciller) ; also in the Post-pliocene of Europe. Recent — V^ery abundant throughout the Gull' St. L./'reuce and coast of Nova Scotia and New England, also Arctic seas generally. Mr. Jefl'reys considers it identical with M. Jajjonlca, Jay. Not found yet in W. America. (P. P. C.) In the Gulf this species grows to a large size; I have a speci- men five inches long from Gaspe; but in the Post-plioceue it is 1 - i'.'. *■;'■-■ ;i 72 DAW80N — l'08T-PLIOCENE. m 'mi small and often of a short and rounded variety. This is espe- cially the case inland, as at Montreal. At Riviere-du-Loup a small thin variety with a strong epidermis and attenuated poste- riorly, is found in situ in its burrows in the Leda clay. It may be a deep-water variety. Some large specimens in collections from this place, I have reason to believe are from Kitchen-mid- dens and not fossils. Kcnnerlia glacialis, Leach Fossil — Leda clay; St. John, New Brunswick; Saco, Maine. Recent — Gaspd (Whiteaves); Murray Bay; Labrador (Packard). This species, which was at first confounded with Pandora tiilincahi by Dr. Packard, is evidently quite distinct, and on the evidence of the hinge would belong to a different genus. Much nearer to Pantlora pinna, Mont. ; = P. ohtusa Forbes and Han- ley. J. F. W. Lyonnia (^Painlonna') arenosa, Moller. Fossil — Leda clay; Montreal (rare and small); Rivi6r8-du- Loup, common; Duck Cove, N. B. ; Saco, Maine; also in Greenland (Mcdler). Recent — M urray Bay and Gaspd ; Halifax (Willis) ; Green- land (Moller) ; Labrador (Packard). Some specimens from Portland are much larger than thot,e from Riviere-du-Loup and Montreal, and Mr. Whiteaves finds individuals an inch long, living at Gaspd. Thracia Conradi, Couthuoy. Fossil — Saco (Packard). Not yet found fossil in Canada, but recent, though rare, in Nova Scotia (Willis) ; and at Gaspd. Also, though apparently rare, at Labrador (Packard). Has probably extended its northern limit to Canada, since the glacial period. Macoma Gravlandici, Beck. Fossil — Saxicava fsand and Leda clay ; Montreal ; Ottawa ; Perth, Ont. ; Pakcnham Mills, Cornwall ; Clarf^nceville ; Upton ; Quebec ; Murray Bay ; Riviere-du-Loup ; Labrador ; Lawlor's lake, N.B. ; Campbcllton, P. E. I. ; Westbeach, Maine; Green land (Moller). Recent — Everywhere on the coas'., of the Gulf and River St. Lawrence, as a common littoral shell. » DAWSON — POST-PLIOCENE. 73 A thin aud dolicate variety with smootli epidermis is found in tlie Leda clay ; coarser aud more wrinkled varieties in the Saxi- cava sand. Lar<;er specimens are found at Quebec and Riviere- du-Loup than more inland. In the modern Uulf, the small and depauperated varieties are littoral and near the brackish water, the finer varieties passing into Macoma fusca of Say, which is a southern variety, are found on the coast of Nova Scotia and in the Bay of Fundy. This shell is represented in the European seas and Post-pliocene de- posits by the closely allied species M. solidula or Boltkicn, which seems to pass through a corresponding series of varieties, but to be distinct. On the western American coast it is similarly represented by M. uicumpicua. Mr. Tryon and Mr. Whitcaves believe the three iorms to be conspecific. (P. P. C.) It is said to be the Tclllua Fahvici't of Hanley, and I have specimens from tlreenland from Morch labelled T. tinera. The T. Uiwra of Leach, however, is proximc, Brown, teste Hanley. It is apparently the Venus frdgills of Fabricius. It is one of the most common and abundant shells of the Post- pliocene, as it is of the American coast from Greenland to New England. Macoma calcarea, Chemnitz. Fossil — Leda and Boulder clays ; Montreal; Quebec; Murray Bay ; Riviere-du-Loup ; Duck Cove. St. John, N.B. ; Maine ; Labrador ; Greenland (Mollcr) ; also European Post-pliocene. Recent — Arctic seas generally, aud on the Americau coast south to Massachusetts. This shell is is extremely abundant in the Leda and Boulder clays, and often occurs in tlie clay with the valves attached. It is also of large siie and in fine condition, especially at Riviere-du- Loup. It is TelUna proxlma, Brown, T. sahulosa, Spengler, and T. sordida of Couthuoy. According to Hanley, the T. lata of Gmelin was founded on a figure of this shell. Macoma wjlata, Stimpson. Fossil — Montreal ; Rivi(^re-du-Loup. Rare. Recent — Murray Bay, and dredged in deeper parts of the Gulf of St. Lawrence by Mr. Whiteaves. I am not aware where this little shell has been described, nor what is its range. It seems identical with a specimen in Jeffrey's collection labelled Tctlina frag'dis Lea'^h, from Spilzbergeu. '•>Mt 'A :}. ' ) : f I I i*| ,kl? 74 DAW80N — POST-PLIOCENE. The Post-plioceno specimens are larj^er and better developed than the roceat, except some dredj^ed by ]Mr. Whiteavcs ou the north sliore, and I would infer from this that the shell is Arctic. (See Figure.) Ci/rtoihtrUi siliqitn, Daudia. Fossil — Rivieredu-Loup ; Labrador (Packard) ; Greenland (Miiller). T have seen in the Post- pliocene of Canada, only an imperfect and decovticated specimen of the young shell from Riviere -du-Loup. Recent — Gulf of St. Lawrence, and coasts o^ Nova Scotia and New England. Mactra (Sptsuhi) ovilis, Gould. M. pofi/iie)iiit, Stimpson! Fossil — Boulder clay ; Cape Elizabeth, Maine. Recent— Gaspe ; Labrador (Packard); also coast of New England. I found, many years ago, a few specimens of this shell at a cove where a number of species of marine shells occur in Boulder-clay, and it wrn published in my list of shells from this place in my paper on the Post-pliocene of Labrador, Maine, &c. It is credited by Packard to " Zeeb's Cove," Cape Elizabeth, which may prob- ably be the same place where I procured it. This species has not yet been found within the limits of Canada in the Post-plio- cene, though this and the related species or variety, /'/. so/idis- sima, are found living at Labrador. It has perhaps moved northward since the glacial period. Mesodcsma (Ctronia) deduntfa, Turton. Fossil — Matanne River (Bell.) 1 have not seen it in any other locality ; and it occurs only ou the lowest terrace, so that possibly it is modern. Recent — Abundant at Tadousac and elsewhere in Gulf St. Lawrence; Labrador (Packard.) This must be a modern species on our coasts; but according to Wood it is found in the Red Crag of England. Venericardia (Cardi'ta) horealia, Conrad. Fossil — Jjabrador (Packard. ) Recent — Arctic seas to Long Island, and common throMghout the Gulf of St. Lawrence. It would seem to have het'ii much less generally distributed in the Post-pliocene. Western America as far south as Catalina ^slaud. (P. P. C.) H K ■^ DAWSON — POST-PLIOCENE. 75 Asfarte Laureiifiana, Lyt-U. Fossil — Lcda clay, Montreal, iibiuiclfint; Beauport .uiil Rivi«>re- du-Tjoup, rare. Recent — Greenland (Morch) ; Jjabrador (Packard) ; Murray Bay. This shell may bo a variety of the next species; but it is at least a very distinct varietal I'orni. It is distinguished by its very tine and uniform concentric striation, passing to the ends of the valves and to the ventral margin. There are twrt varieties, a flatter, and more tumid. I have the former from Greenland named by Morch A. Baiiksii, and the latter named A. utritito. ; but they are different from shells indicated by these names in Gould and elsewhere. The only recent specimens that I have seen from the Gulf of St. Lawrence, which can be referred to this species, are a few 1 dredgi-d at Murray Bay. A. Lauren- tiana is very abundant at Montreal, but much more rare nearer the coast. It is evidently an Arctic form. (See Figure.) Axtarte BanksH, Leach. Fossil — Leda clay, Rivierc-du-Loup, abundant; Quebec, not infrequent ; Montreal, very rare ; Labrador (l*;ickard) ; Portland, Maine, also Uddevalla, Clyde beds and Crag. Recent — Abundant at Gaspe and elsewhere in Gulf of St. Lawrence, and also Arctic seas and coast of Nova 8cotia. This shell is that named ^1 Banksii, in Gould's last edition, also in Bcechcy's voyages. It is easily distinguished from the last species by its coarser striation, fading toward the ends and also toward the margin of the shell. It is however about the same size, but less delicate and symmetrical in form. It is the common small Astarte of the Gulf St. Lawrence, and also of the Post-pliocene of Riviere-du-Loup ; but becomes very rare at Montreal, where it is replaced by A. Laurentinna. This species was named A. ronqrrcssa in my former lists, and it is certainly very near to European specimens of that species, especially to the fossils from the Clyde beds and the Crag. (See Figure.) Astarte Elliptiai, Brown. Fossil — Labrador ; Saguenay ; Portland, AL-iine. Recent — Labrador ; Murray Bay ; Gaspe ; coast of Nova &c. Also Greenland ; Norway (typical) ; Scotland. Specimens from the Clyde beds are perfectly identical with ours. It is also found in the Post-pliocene of Norway and rarely ^-■•1 -'n i!|if. I i mi. Mr . ;.■ t 11! ■ ' i 11 'I i i 1 1 ■. I- ''' !,■■ il r: 76 DAWSON — rOST-PLTOCENE. in the Crag. Tt is a uorthern species meeting on the American coast the closely allied forms A. fhidaUi and A. fens, into which however it does not seem to pass. The two latter species, being more southern forms, are not found in the Post-plioceae. A. Omdlli of iS. Wood from the Crag, is very near to this species, but is at least a distinct variety. Asfarte Arctica, Miiller, (var Lactea.) Fossil — Labrador (Packard) ; Portland, Maine ; also (ireen- laud, (Moller). Recent — Uaspe; also Arctic seas ; Norway (typical). This species has not yet been found in the Post-pliocene of Canada, except in Labradoi ; and it seems to be a rave shell in the Gulf of St. Luwrence. It is our largest Astarte and I believe it to be identical with A. borealis, Cliem., ^1. lactai, Brod. and Sow., and A JSemisitlaita, Gray. Fossil specimens from Port- laud, are precisely similar to recent ones from Gaspe dredged by Mr. Whiteaves, and rel'erred by him to A. hu'tea. Specimens from Norway (vl. Arctico) and from Clyde beds (.1. liitrailis) are smoother and less ribbed than ours. Other species of Astarte. At Murr«y Bay, there occurs very rarely a transversely elon- gated and regularly striated Astarte with delicately wrinkled epidermis, which seems to be identical with .4. Rkluinhonii \'vo\\\ the Arctic seas as described but not as figured by Reeve. It is not improbably a young state of Astarte Arctica. A similar species or variety occurs, but very rarely, fossil at Riviere-du-Loup. A. sulcata, (undata), A. lens, A. crehricostata, A. castanea, and A. quadrans have not yet been found fossil, though the three former at least live in the Guif of St. Lawrence.* Cardium pinmdatuni, Conrad. Fossil — Leda clay, Lawlor's Lake, N.B. Recent — Gulf St. Lawrence, and coast of Nova Scotia and New England. * A. undata Gould and A. quadrans, Goulil, ccrtainlj' occur in tli'^ Gulf of St. Lawrenco N. of thu Baj of Chalcurs. A hIicII diodgcd in deep water N. of Anticooti may bo A. crebricostaln. A. lens, Stirai)son, and A. caslanea, Say, iiavc not yet occunod to mo in dicdgiugs fiuni more than 60 localities N. of New BrunHwick. J. F. VV. DAWSON — POST-PLIOCENE. 77 Cin-diiim fslandlcnm, Linn. Fossil — Riviere-du-Loup ; Murray Buy ; Siiguonay ; Portland, Maine ; Lawlor'e Lake, N.B. ; Greenland, Moller). Recent — Prom Greenland to New England. Our fossil specimens arc mostly small, and similar to the northern variety or sub-species named by Stimpson C. ILtyseii, and which also occurs living as far south aa Nova Scotia, and seems to be the C\ rUiafum of Fabricius. Decorticated speci- mens are not distinguishable from (J. AnrsoHtt of Stimpson, from the Post-pliocene of Hudson's Bay; of which I have seen only specimens in this state. Serriprsi Gnrnlnmfica, Chemnitz. Fossil — Leda clay, and Boulder clay, 'Quebec ; PtiviiVe-du Loup; Murray Bay; Lawlor's Lake, N.li. ; Cape Elizabeth, Maine; Labrador, (Packard) ; Greenland (Moller). Recent — Gulf St. Lawrence, sometimes of large size, Arctic .«*eas, and Greenland to Cape Cod. This shell is somewhat rare and of small size in the Post-plio- cene, and has not yet been found higher up the St. Lawrence than Quebec. Specimens of good size occur at Portland. (Jri/ptodou (Joiddll, Philippi. Fossil — Montreal, rare. Recent — Murray Bay; Ga.spd (Whituaves) ; Greenland to New England. The European form Cfexunm is usually regarded as di.'itinct, and is found as far north as Spitzbergen, and in the Crag, the (ylyde beds, and the Norway Post-plioceno. Jeffreys, however, considers the difference merely varietal, and it certainly seems to diminish or disappear in the northern and glacial specimens. According to Mr. VVhiteaves this species has a great range in depth in the Gulf St. Lawrence, being found, living, from 20 to 300 fathoms. i^phaennni 7 Fossil — Pakenham Mills, with fresh-water bivalves and 2\lUna Gramhuidica. The specimens were too imperfect for certain determination. Unio rectus, Lamarck. Fossil — Clarenceville, Lake Champlain (Dickson), with Mya arenaria, Tcllina Gnrnhmdicay &c. Recent — River St. Lawrence. I., ■ )'■ 'f^% IMAGE EVALUATION TEST TARGET (MT-3) 5< /. ^ fA 1.0 I.I 1^128 |2.5 ■50 '*^~ MflB :^ 1^ III 2.0 2.2 1.8 1.25 i 1.4 1.6 V] 4^1^> ^>Lr^^ .-> 7: y /^ , If K^^ i? k r^ i "I 11^ ill I ■' : 78 DAWSON — POST-PLIOCENE. Uiiio Cardium ? Rafinesque. Fossil — With the preceding. This and the preceding species were represented by large and thick shells better developed than those of the River St. Lawrence at present. It is probably the same with If. ventricosus, Say. Mytilus eduUs Linn. Fossil — Montreal ; Acton ; Rivi^re-du-Loup ; Quebec ; La- brador (Packard) ; Lawior's Lake, N.B. (Matthew) ; Green- land (Miiller). Recent — North Atlantic and Arctic seas generally ; North Pacific (= trossulus, Gould) as far south as Monterey. The variety most commonly found in the Post-pliocene is a small, oval, tumid form, allied to variety elegans of British writers (see figure). This variety still lives at Tadoussac ; and is apparently characteristic of situations where the water is cold and exposed to intermixture of fresh water. The ordinary variety occurs at Portland, and also in some of the upper beds at Rivi^re- du-Loup. At Montreal only the small oval variety occurs. This variety is also found in the Clyde beds and in the crag. Modiola modiolus, Linn. Fossil — Montreal, very rare. Recent — Labrador to New England ; very common on the coasts of Nova Scotia and New England ; North Pacific; found sparingly along the Vancouver and Californiau coasts till it is replaced in the Gulf fauna by M. capax, Conrad. This species becomes rare to the northward ; and this, as well as its being proper to rocky shores rather than to clays and sands, may account for its rarity in the Canadian Post-pliocene. It is, however, common in the glacial beds of Europe. ModioJaria nigra, Gray. Fossil — Montreal ; Rivit^re-du-Loup (small variety nexa ; also large and fine) ; very large and well preserved in nodules at Kennebeck, Maine ; Labrador (Packard of his M. discrepans as I suppose.) Recent — Gulf of St. Lawrence (Whiteaves). Very large and fine on coast of Nova Scotia (Willis), and as far north as Green- land (iW. discors, Fabricius). Modiolaria cornignta, Stimpson. Fossil — Rivi^re-du-Loup. DAWSON — POST-PLIOCENE. 79 Recent — Murray Bay and Cacouna ; precisely similar to the shells from the Post-plioccnc. Also Greenland (Moller) ; La- brador (Packard) ; and south to Cape Cod. Mndiolaria discors, Leach. Fossil — Beauport, of good size; Greenland (Moller). Recent — Labrador to New England. Specimens from Gasp<5 are precisely similar to the fossil. This shell is no doubt identi- cal with M. Imvlgata of Gray, and possibly with the M. discre- paiis of some other authors. It is however the same with that figured in Binney's Gould as M. discors. Crenella glunduhi, Totten. This species, which is; at present quite common in the Gulf St. Lawrence, is indicated in my formerly published lists as a Mont- real fossil ; but I have mislaid the specimens, and cannot there- fore now repeat the comparisons with the recent shells. According to Mr. Whiteaves this is quite distinct from (J. dtcas- sata, Montagu, both being found living in Gaspe. Nucnl'i tennis, Montagu. Fossil — Leda clay, Montreal ; Saco (var. injiuta) ; Riviere-du- Loup ? Recent — North shore Gulf St. Lawrence to Gaspe (Whiteaves) type and var. inflata ; also European coasts. N. expansa, Reeve, Fossil — Leda clay and Boulder clay, Riviere-du-Loup ; Saco ; Duck Cove, St. John, N.B. Recent — Labrador (Packard) ; Murray Bay ; Arctic seas. I doubt if this is not a large and well-developed northern form of N. tenuis. N. iintiqua, Morch, from Leda clay of Maine, seems to be a variety. ^ Leda permda, Muller. Fossil — Leda clay, Rivi6re-du- Loup; Portland; Saco; Law- lor's Lake, N.B. (Matthew). Recent — Arctic seas and south to New England. This shell occurs very abundantly at Riviere-du-Loup ; and the specimens found there show that no specific line can be drawn between the forms known iia permda, buccata (Steenst.), i if. li- ■ € I 80 DAWSON — POST-PL lOCENE . :» -t" C. H.-. tenuisulcata, Gould, and Jacksonii, Gould. Slender and flat- tened varieties are pemul/i and tenuisulcata, shorter and more tumid forms are huccata ; and specimens decorticated so as to show the origin of the hinge teeth are Portlandim. Comparison of specimens from Greenland, Norway, Labrador, the Gulf St. Lawrence, and New England, confirms this conclusion. (See Figure.) Leda tiunuta, Fabricius. Fossil — Leda clay, Montreal ; Rivi6re-du-Loup ; Greenland (Miiller) ; Labrador (Packard). Recent — Arctic seas, Gulf St. Lawrence ; coast of Nova Scotia. The fossil specimens occur abundantly with the last species at Rivi^re-du-Loup, and are quite similar to those dredged at Mur- ray Bay. This was called L. cMudata in my former lists. _^ Ltjda pygmoia, Munster. Fossil — Leda clay. Green's Creek, Ottawa ; Saco ; Maine ; also English Crag and other Glacial beds. Recent — North European seas ; but not yet recognized on the American coast. According to Mr. JeflFroys and Dr. Carpenter, our drift shells are referable to the variety or species Yoldia abys- slcola of Torell. Leda (^Portland'ui) glactalis, Gray; trunmta, Brown. Fossil — Leda clay and Boulder clay, Montreal ; Quebec ; Ot- tawa River ; Rivi6re-du-Loup ; St. John, N.B. ; Portland and Saco, Maine ; also in Post-pliocene of Norway (Sars), and of Scotland (Crcsskey). Recent — Arctic seas. This shell is most abundant, and generally diffused in the Leda clay ; and the variety ordinarily found at Montrenl and Rivi^re- du-Loup is precisely identical with the ordinary Arctic form. A long variety, called L. interrtux 'a by Sars, is also found at Mont- real, though rarely. A short variety, common in the Post plio- cene at Murray Bay, is similar to the L. siliqua of Reeve from the Arctic seas ; and young and depauperated varieties resemble L. mici/era of the same author. The abundant material from the Post-pliocene shows that these are all varietal forms. This shell is Yoldia Arctica of Sars, but not of Moller and Morch. It is V. truncata of Brown. It is Portlandia glacialis of Gray, and Leda Fortlaiidica of Hitchcock. DAWSON — POST-PLIOCPiNE. 81 m 18 Yoldiit lucida, Lovdn (which is abundaut living in the deeper parts of the Gulf of St. Lawrence) closely resembles the young, smooth form of this species, but I think the two may be dis- tinct. J. F. W. Leda (Yohlla') Umatvla, S;iy. Fossil — Leda clay, llivi^re-du-Lonp. Recent — Gulf St. Lawrence to Long Island. This shell has buen found as yet only at Riviiirc-du-Loup, where the specimens however are as good as those now living in the Gulf. (See Figure.) It will be observed, however, th..t though they have the numbc" cf teeth of Y. liinntidd, they ap- proach in form to the allied species or variety Y. sajjotiUa, a shell which occurs in Greenland and thence to New Enghmd, and which I strongly suspect is merely a short v.iriety bearing a simi- lar relation to Y. Ihnatida to th^it which Ali/a Uddevallensis bears to the ordinary M. tnmaita. Y . sapotilla is, I may men- tion, the Y. Arctica of Morch, as proved by a specimen from his collection now in my possession. Leda {Yoldi.a) mijruls, Couthuoy. F(/Ssil — Labrador (Packard). Recent — Gaspu (Whiteaves) to south of Cape Cod. This shell is supposed to be identical with N. Ju/perborea, Loven, from Spitzbergen. Pecten Graidandiciis, Chemnitz. Fossil — Leda clay, Portland and Saco, Maine ; not yet found in Canada. Recent — Gulf St. Lawrence (Whiteaves) in deep water 200 to 300 fathoms. This species is found in the Clyde beds and in Greenland ; and if, as JeiFreys supposes, identical with P. simiHs (Laskey), it is a shell of very wide distribution in the Atlantic, as well as in geological time. Though not yet found in Canada as a Post- pliocene fossil, its occurrence as a fossil in Maine and recent in the Gulf St. Lawrence, renders it probable that it may yet occur in our Leda clays. Pecten tenuicostattis, Mighels?. Fossil — Leda clay, St. John, N.B. (Matthew). Recent — Labrador to Cape Cod. This shell has not yet been found in the Post-pliocene of the ■'J i:4 ''"''ill Jill mM 82 DAWSON — POST-PLIOCENE. / St. Lawrence v.ill/ y ; but .since, accordiag to Packard, it is com- uioii in Labrador, there is notliing remarkable iu its occurrence in the Post-pliocene of St. John. IWtni Isliiitt/icns, Chemnitz, Fo.ssil — Riviere du- Loup; Quebec; Labrador (Packard) ; St. John, N.B. (Matthew); Portland, Maine; Greenland ( M oiler) ; also Crag, Clydo beds, and Post-pliocene of Norway. Recent — Gulf St. Lawrence, and from Greenland to Connecticut. This is a shell which is very durable, and retains even its colour when imbedded in the clays. In this it excels the Tel- linas, Astartes, Saxicava and Ledas; though these in turn are always much better preserved than the Mytili and Modiolae. ) '.;• \-'^ Hi Sii' 'M Class IIL — Gasteropoda. Philinc lineolata, Couthuoy. Fossil* — Montreal, rare. Recent — Gaspe ; Grand Manan (Stimpson) ; Nova Scotia (Willis). It is Fhifine lima, Brown, according to JcfFreya. Cylichna alba, Brown. Fossil — Montreal; Riviere-du-Loup; also in the Clyde beds. Recent — Gaspe ; Labrador (Packard) ; Gulf St. Lawrence, common (Whiteaves) ; Arctic seas generally. Same or similar on West Coast at Sitka (P.P.C.) Ci/Uchna ovi/za, Totten. Fossil — Montreal. Recent — Coast of New England, Cyl'nhna nudeola. Reeve. Fossil — Montreal ; rare, and perhijps doubtful. Recent — Arctic seas Cifl'uhna (UTitlto, Mighels and Adams. Fossil — Montreal ; Murray Bay ; Maine. Recent — Greenland to New England. Cylichna striata, Brown. Fossil — Rivit^re-du-Loup and Clyde beds. Recent — Arctic seas. • Except when otherwise Btated, all the Gasteropods are found in the Leda clay, or at its Junction with the Saxicava sand. R I •" ■ DAWSON— POST- PLTOCENE. 83 Bulla {Haminea) solifaria, Say. Fossil— Montreal ; rather common. Recent— New England and northward. If this specie, is rightly determined, it furnishes a curious in- stance of a somewhat southern species occurring in the drift of Mon real The Hamu.ea, however, can scarcely be identified by weathered or fossil specimens, so that this may possibly be a nor- thern form distinct from soUtaria. Bulla (Diophana) delnlis, Gould. Fossil— Montreal. Eecent-Gulf St. Lawrence (Whiteaves) ; Green), nd to N. w Jinglanl. It IS a shell of the Clyde beds and of the Arctic seas generally." ' Bulla (CTtnadus) pcrfcnids, Mighels. Fossil — 3Iontreal. Recent-Labra-lnr (Whiteaves); Gulf St. Lawrence, and south to Cape Cod. According to Jeffreys it is U. turntus, Moller, Greenland. ffelix striatelln, Anthony. Fossil— Pakenham, Saxicava sand. Lymnea umhrosa, Say. Fossil— Montreal. Lymnea caperata, Say. Fossil— Montreal. Lymnea elodes, Say. Fossil— Pakenham Mills, Saxicava sand. Planorhis Incarinatus, Say. Fossil— Pakenham Mills, Saxicava sand. Planorhis trivolvis, Say. Fossil- Pakenham Mills, Saxicava sand. y X A Planorhis parvus, Say. Fossil— Pakenham Mills, Saxicava sand. >^ All of the above pulmonates are modern Canadian species and seem to have been drifted by some fresh-water stream into' the sea of the Saxicava sand and Leda clay. - M • I 84 DAWSON — POST- PLIOCENE. ll^^i-^. ]tl hr S{j)hono-dentnh'.vm vitreiim, Sars. Fossil — Leda clay, Murray Bay; also Norway (Sars). Recent — Gulf of St. Lawrence (Whiteaves) ; coast of Norway (Sars.) It. is a rare deep-water shell. Amicula Emersonii, Couthuoy. Fossil — Moatreul. Recent — Murray Bay ; Halifax ; coost of Now England. My specimens are merely detached valves. They indicate an animal quite similar to specimens from Halifax referred to this species, but differ slightly from specimens from Murray Bay. Dr. Carpenter has labelled the drift form var. '• altior." The dif- ferences among the recent specimens, as well as the fossil valves, will be discussed in the " Contributions to a Monograph of the Chitonidee," about to be printed by the Smithsonian Institution. Puncturella {Cemoria) Noachlna, Linn. Fossil — Quebec ; Rivi^re-du-Loup ; Clyde beds. Recent — Gulf St. Lawrence generally ; and throughout the Arctic seas and North Atlantic. Acmcea testad'inalis, Moller. Fossil — Labrador. Recent — Gulf St. Lawrence generally ; and throughout the Arctic seas and North Atlantic. My only fossil specimen, obtained from Dr. Packard, is of the small, elevated and depauperated variety so common at Murray Bay and the north shore of the Gulf. It is curious that this common modern species is so very rare in the Post-pliocene. Lepeta coeca, Moller. Fossil — Montreal ; Rivi^re-du-Loup ; Quebec ; Labrador ; European Post-pliocene. Recent — Gaspd ; Labrador ; Arctic seas generally ; and coast of New England rarely. This shell is not at all rare, living at Ga.«p^, and fossil at Rivi6redu-Loup. Carpenter remarks that some of my Montreal specimens have the characters of variety striata of Middendorff from Siberia. Capuhis commodus, Middendorff. Fossil — Point Levi, near Quebec. One specimen only, found by Mr. Gunn and communicated by Dr. W. J. Anderson. Recent — Scotland (Jeffreys). DAWSON — POST-PLIOCENE. 85 This species is fossil at Uddevall.-), and is supposed to be the same with C./allnx and C. ohl, -qua (us of Wood from the English Crag. It has not yet been recognized on the American coast. (See Figure.) Margarita helieiur, Fubriciu». Fossil— Montreal ; Murray Bay. Young specimens resemble M. acuminata of Mighels. Brond Specimens resemble M. vampauuJata, Morse. Recent—Arctic seas ; Gulf of St. Lawrence ; and coast of New England. It is M. Arctica, Leach. Margarita argcntata, Gould. Fossil— Montreal, rare. Recent— Labrador and Gulf St. Lawrence (Whiteaves) ; Mur- ray Bay ; Gaspd ; coast of Now England and Nova Scotia ? Possibly the same with M. ghuca, Moll., from Greenland. Margarita cinerea, Couthuoy. Fossil— Riviere-du-Loup, Portland. Recent— Gaspe; Labrador; Greenland to New England ; var. striata, Dall, Sitka. Cyclostrema (Mdlleria) costidata, Moller. Fossil— Montreal ; Clyde beds; Uddevalla. Recent -Gaspe ; Arctic seas to New En<^land. Cydostrema Cutler iana, Clark. Fossil — Montreal, rare. This is an Arctic and British shell, as yet recognized only at Montreal. Turritella erosa, Couthuoy. Fossil— Lnbrador; Rivi^re-du-Loup ; Montreal? Recent — Greenland to New England. Turritella reticulata, Mighels. Fossil— Labrador (Packard). Recent— L:.bn.dor to Gulf St. Lawrence ; also fishing banks Nova Scotia (Willis). ' My specimens received from Dr. Packard are marked T. costu- lata, but seem rather to be the above species. .,1 86 DAWSON — POST-PLIOCENE. ; !•' 1^ 181?! Turrit ella acicula, Stimpson. Fossil — Rivi6re-du-Loup ; Labrador (Packard). Recent — Murray Bay ; coast of New England. There may be some reason to donbt whether this is not a variety of T. erosa. It is quite possible that the above species should be regarded as Mesal'uv. Paludina (Melantho) decisn, Say. Fossil — Pakenham Mills, Saxicava sand. Recent — Eastern America generally. Valvata tricarinata, Say. Fossil — Pakenham Mills, with the preceding. Recent — Eastern America generally. Amuicola liniosa. Say. Fossil — Pakenham Mills, with the preceding. Recent — Hudson's Bay to Virginia. Til is was A. porata of the previous lists. Littorina rudis, Donovan. Fossil — Riviere-du-Loup ; also Clyde beds and Uddevalla. Rvcent — Arctic seas io New England and European coasts. L, tenebrosa, which may be regarded as a variety, is also found at Rivi^re-du-Loup. Rissoa castanea, MoUer. Fossil — Montreal. Recent — Gaspe ; Labrador ; Trinity Bay (Whiteaves). Rissoa exarata, Stimpson. Fossil — Montreal. Recent — New England. Rissoa scrobiculata, Moller. Fossil — Montreal. Recent — Greenland; Gulf St. Lawrence, 200 to 300 fathoms, large; and small, Gasp6, 30 fathoms (Whiteaves). Bela harpularia, Couth uoy. Fo.ssil — Montreal; Quebec; Murray Bay; Rivi^re-du-Loup (large specimens). Recent — Gulf St. Lawrence ; very fine at Murray Bay, and similar to lirge specimens from Rivi^re-du-Loup; coast of New Englimd. It is B. Woodiana, Moller (J. F. W.) DaWSOX — POST-rLIOCENE. 87 Beta elcgrinti, Mcillor. Fossil — Montreal. Recent — Grecnliuid anely allieil tn next sjtceies. Bflii pijniinididis, Strom. Fossil — Montreal ; also Ciajij Clytle beds and Uddevalla. Recent — [iabradnr (Packard); Gulf St. Lawrence (White- aves) ; Murray Bay, and south to (!apcCod; Arctic seas gem - r.illy. It is the H. jtfturutointirid ot'Couthouy. and B, Vahlii of Beck. Bela turrictilti, Montagu. Fos.sil — Montreal; Riviere du-Loup; Labrador; also Red Craf:j and Uddevalla (Jeffreys). Recent — Gulf of St. Lawrence and coast of Nova Scotia and New England. I include under this name /?. «o'»7*.sof MoUer ; B. Americaivi, Packard; H. .svi/aris, Miiller; B. exarnta, MuUer, Morch ; and B. angulofii, Reeve. The var. iiobih's is found at Montreal and Gasp^ ; also young sl'ells not distinguishable from crjirata. Var. scaliiris, occurs at Rivit-re-du-Loup and Labrador. This shell is a widely diffused and somewhat variable northern species. Mr. Whitcaves, hewever, regards B. nobilis, B. exaratd, and B, scu- hris as distinct. Bela Trenc/fiiinn, Turton. . Fossil — Riviere-du-Loup ; Labrador ; also Clyde beds and Norway (Jeffreys). Recent — Murray Bay; Arctic seas, and Greenland to Massa- chusetts. It is probably B. ilrci(ssat Portland, Maine. * llecent — Greenland to Cape (/od. Common and extensively distributed in the Post-pliocene of Europe, from Norway to Sicily, and found at an elevation of 1330 to 1360 feet in Moel Tryfaen, Wales. (Darbyshire). Luna fid heros, Say. Fossil — Bcauport, a sittijlc specimen only, and this of small size. Recent — Labrador and southward. This species is as old as the Miocene Tertiary ; and in the Post- pliocene, Canada was probably its extreme northern limit. /y H Hfi t la Groen Ion dicn , Bt'ck . Fossil — Montreal; Quebec; Rivit-re-du-Loup ; Maine; also Post-plioccne of England, Scotland, and Norway. Recent — x\rctic seas generally ; and extending to Britain and New England. L. pallida is the representative of this species on the west coast of America. Choristes elegans, Cpr. Fossil — Saxicava sand, Montreal, rare. This shell was identified in my former papers with Natka helicoides ; but it is now found to be quite distinct, and Dr. P. P. C rpenter describes it as a new species and genus as follows: Genus Choristes. Testa helicoidea, tenuis ; epidermide induta ; anfractus dis- junct i; labrum postice angulatum, antice baud emarginatum ; labium planatum ; columella simplex. Animal ignotum. Choristes elegans, n. s. Ch. t. satis elevata, tenui, nitente ; epidermide fulva, tenui, laevi, extus et intus omnino appressii; anfr. iii. -f- ?, vertice nucleoso decollato, spiralitcr obsoletius striatis ; lineis increment! tenuissimis ; spirS, superne planata, suturis maxima impressis, basi tumente; umbilico intus majore, extus modico; aperturd sublunatS, postice ad angulum circ. 30° inclinatu, antice late rotundritS ; labro acuto, postice planato ; labio acuto, planato, baud reflexo ; columella postice regulariter arcuatd, neque emar- ginata, nee angulata, nee insculptS. DAWSON — P08T-PLI0CENE. 89 P. lUl, tice snti sis, urfi, iltC ito, liir- Long. (npicc decollato) 82, toiig. spi'r. '32, hit. 76. poll. Div. 90". f/iih. Montreal, in strato "ilaciuli, lusi^ilis, raris.**inio rr'porta. Mus. Daw.son, Mci^ill Coll., Nat. Hist. Soc. Or. Carpenter adfl,s the following remarks: While almost all the other drii't fossils are of speeies still living in the neighbouring seas, this is not known, even generically, to be at present in existenee. It is hard to pronounce satisfactorily on its relationships. In its thin, coated shell it resembles Velu- tina ; the striae and loose whirls recall Naticina ; the straight pillar lip reminds us of Fcssarus; while the umbilicus and rounded base, with entire ni< .i best accord with the Natica group. With Trichotropis un(i ongeners I can see no resem- blance. One remarkable feature m all the specimens is the de- collation of the upper whirls, seen even in a nearly perfect young specimen, -2 across ; other young specimens, even smaller, have only one whirl and a half remaining. The broken portion is filled up not so much by a septum as by a solid thickening. The separation of the whirls is complete from the beginning ; and although, in the parietal portion, they are closely appressed, the smooth and somewhat glossy epidermis is distinctly seen between. The fracture of the mouth in most of the specimens, enables this feature to be distinctly observed ; and would also reveal the " internal groove " and columellar callosity ascribed to Torellia, did any such exist. The straightening of the inner lip, at an angle of 30° from the axis, makes the umbilicus by no means large (for a Naticoid shell) when viewed from the base in the line of the pillar ; but the same cause enlarges it within, recalling the adult appearance of Amphithalamus. The flattening of the upper portion of the whirls gives the shell somewhat of an lanthiaoid aspect. While the analogies of the shell point in so many diflFerent 'directions, it is impossible to assign it even to its family group. XL is to be hoped, however, that the dredge will yet reveal its existence in a living state. The above species may be supposed to resemble Torellia ves- tita, Jeffreys, from Norway. Our specimens differ however in form, as above noted, and also in the absence of the tooth in the inner lip, and in the smooth epidermis. The shell in question presents the very unusual character of having the whirls appressed, yet quite disconnected ; the smooth '4 .'it ■V 90 DAWSON — POST-PLIOCENE. h ■• :: ,1 t •t- 1--; epidermis lining the umbilical chambers, and conspicuously pre- served, even in these fossil specimens, between the closest parts of the parietal region. In this respect it bears the same relation to Torellia as does Latiaxis to Rapuna, Separatista to Rhizochilus, or Zanclea to Torinia. It presents a rude resemblance to Separa- tista Chemuitzii (Add. Gen. pi. xiv. f. 6), or still more to S. Blainvilleana (Ch^nu Man. p. 172, 4^ 853), but without the grooved pillar, or the keels of the latter species. ♦ As to the "blunt tubercle" or " callous protuberance " of Torellia, described by Mr. JeiFreys, but scarcely to be traced in Mr. Sowerby's figure, it certainly does not exist in our fossils. It is not always a character of importance, as may be seen by comparing Purpura columellaris with P. patula, Cuma tectum with the remaining species of the genus, or the gradual transition from Isapis to Fossarus. The Naticidao arc often very irregular in the callous region of the pillar, even in the same species. Velutina zonula, Gould. Fossil — Montreal ; Beauport. Recent — Arctic seas to Massachusetts. According to JeflFreys, this shell is the same with V. vndntn, Smith, from the Clyde beds, and is found in the Crag and in the Post-pliocene of Uddevalla. Scalaria Grcenlandica, Perry. Fossil — Rivi^re-du-Loup ; Quebec ; Saco ; also Scottish Post- pliocene and English Red Crag, under same varietal forms as in Canada. Recent — Arctic seas, and American coast, as far south as Massachusetts. The specimens from Rividre-du-Loup are very large, one being nearly two inches long ; and, as Dr. Beck has remarked, the varices of some of the specimens are more slender and lamellar than in recent specimens, others, however, are similar to the more common recent variety. Acirsa Eschrichtii, Holboll. Fossil — Quebec; Riviere-du-Loup ; Montreal ; most abundant at Riviere-du-Loup. Recent — Murray Bay; Greenland; also Eastport (Verrill.) This shell was named in former papers Menestho albiUa, the eroded specimens found being referred to that species. It has, [Iff DAWSON — POST-PLIOCENE. 91 however, been correctly described by Dr. Beck in Lyell's paper on Boauport, and named Sea/ana horea/ls. It is not this species ot Grould, however. Trichntropis boreaUs, Brod. and Sow. Fossil-Montreal; Riviere-du-Loup ; Labrador, &c. ; very abundant at Montreal. Recent-Labrador, Murray Bay, Gaspe, Arctic seas, and as lar south as Massachusetts. Trkliotropis arctica f Middendorff. Fossil — 3Iontreal, very rare. A single imperfect specimen represents this species, which is recent at Behring's Straits. The identification is perhaps doubt- ful. ^ The figure given by Reeve of T. Kenseri of Phillippi from fep.tzbergen, resembles our shell, except in the small number of revolving bands. Admete viridula, Fabricius. Fossil — Montreal. Recent— Labrador, (Packard); Murray Bay; Gaspd, (White- aves) ; also Greenland and Labrador. It is the Tritonium vir- idulum of Fabricius, and is a rare shell in the Canadian Post- pliocene, and in the Gulf of St. Lawrence. Aporrhais occidentalis, Beck. Fossil— Labrador (Bayfield) ; also Packard. Recent — Labrador to Massachusetts. It is remarkable that this species, which is found living from ' Labrador to Cape Cod, is so rare in the Post-pliocene. Fasciolaria ligata, Mighels. Fossil — Montreal, very rare. Recent—Murray Bay; Mingan (Foote) ; Gaspd, (Whiteaves); Novu Scotia, (Willis) ; rare in all these localities. A single mutilated specimen alone, as yet, represents this species in my Post-pliocene collections. Astyris HolhoUii, MoUer. Fossil— Rivi^re-du-Loup; also glacial beds Britain (JeflFreys) Recent— Gasp^; Murray Bay; Labrador, (Whiteaves). If identical, as I suppose, with Polumhella rosacea, Gould, it ex- tends south to New England, and Gould's name has priority lll '$H !if :.'-i ill Hit .:■ V. ■ 'i . 92 DAWSON — POST-PLIOCENE. Bnccinum undatum, Linn. var. undulatiim, Moller. var. L(fhrridoricitni, Reeve. Fossil — Saxicava sand and Jjeda clay, Riviere-du-Loup ; La- brador ; Duck Cove, St. John, N.B. ; Maine (Packard). Recent — Gulf St. Lawrence; south Greenland to Nantucket. (See Figure.) T cannot satisfy myself that there is any good specific distinc- tion between this shell and B. undatum of the European seas and glacial beds. It varies very much in size, in sleuderucss, in the fineness of the spiral striation, in the development of the ribs, in the extension of the mouth, "and in the thickness of the shell. The coarser forms are B. Ldhrddoricum, which passes into the ordi- nary undtitum. Medium xnrieiiaimre B. undulatum, and smooth varieties pass into B. cyanenni and B. Totttnii, which last is the eUiatum of Gould. Bucclnum Toffenii, Stimpson. Fossil — Riviere-du-Loup, Saxicava sand and Leda clay. Recent — Murray Bay and Tadoussiic ; also Newfoundland Biinks. It has some resemblance to B. Hnmphreysianum, Ben- net, but is specifically distinct. It is the B. ciliatum of Gould, but has no connection with the ciliatum of Fabricius, except a slight resemblance to the smoother forms of the latter. . It is re markable for its very regular spiral lines, absence of folds and convex whirls. Buccinum cijaneum, Bruguiere. Fossil — Riviore-du-Loup, abundant. Recent — Murray Bay and Tadoussac ; deeper parts of Gulf St. Lawrence (Whiteaves) ; Arctic seas. This species or varietal form is well represented in the Figure, which is taken from a large Rivi6re-du-Loup specimen. Being on the one hand very near to if not identical with the smooth varieties of B. nndulatnm, and on the other resembling B. Gi'oen- landicum, it has received many names. It is believed to be B. hnreale of Leach, and Groenlandicum of Morch. It is a very characteristic northern form. (See Figure.) Buccinum Groenlandicum, Chemnitz. Fossil — Leda clay and Boulder clay, Montreal ; St. Nicholas ; Riviere-du-Loup. Recent — Greenland. Specimens from Morch are identical DAWSON — POST-PLIOCENE. 9d with our fossils. This species is probably the B. nndatnm of Fiibricius. It is allied to B. njanenm, and may possibly pass into it. (See Figure.) Buadnum temie^ Gray. Fossil — Riviere-du-Loup, not uncommon ; Greenland (Hayes) ; Labrador (Packard). Recent — Murray Bay; Gaspe; Labrador (Packard); Arctic seas generally. A common Arctic species, but rare living in the Gulf, though much more plentiful in the Post-pliocene beds. (See Figure.) Buccinum ciliatum, Fabricius. Fossil — Montreal ; Riviere-du-Loup. Recent — Murray Bay; Greenland (Fabricius) to Nova Scotia (Willis). This is the original B. cih'afnm of Fabricius, and hf.s been recognized as such by Dr. Stimpson. It is easily distinguished by its narrow Nassa-like mouth, armed with a tooth on the front of the pillar lip. It varies much in sculpture, especially in the longitudinal ribs. The variety found at Montreal is only slightly ribbed. That at Rivi^re-du-Loup is more distinctly ribbed, thus resembling the recent specimens from Murray Bay. It is quite distinct from B. ciliatum, Gould, which is very near the smoother varieties of B. nndulafum. As it is a rare and little known shell, I have figured two extreme varieties, a fossil specimen from Montreal and a recent from Mur^-ay Bay. Buccinmn glaciah, Linn. Fossil — Rivi^re-du-Loup; Montreal; Labrador; (Packard.) Recent — Murray Bay; Greenland, and Arctic seas generally. This shell has the aperture somewhat like that of cilia turn and a very peculiar sculpture of spiral striae with intervening bands marked with finer strife. It has also a carina anirulating- the body whirl, and sometimes more than one. In the latter case it passes into B. Gratfilandlcum, Hancock (not Chemnitz) or B Hancnckl Morch. The ordinary variety is most common in the Modern Gulf, the latter in the Arctic seas and in the Post-pliocene. This shell, usually much decorticated, is the most common Buccinum in the Post-pliocence of Montreal. It was called B. undatum in previous lists. I! rl \ H vi m :! ;k 94 DAWSON — POST-PLIOCENE. i! iJ Buccinum plectrum, Stimpson. Fossil — Rivi(ire-du-Loup ; rare. Recent — Murray Bay ; Portland, Maine, (Stimpson) ; Beh- ring's Straits, (Stimpson) . This m.iy be a variety of the prccedini; species, but can be distinguished from it and grows to a larger size. It has the sculpture of B. ghiciib with the aperture of B. unduhitam. Recent and fossil specimens are quite similar. The northern Bucn'na are involved in so much contusion that I have made them a subject of special study, and have sedulously collected all the forms recent and fossil. I have been very much aided in this by the abundance of specimens of the more Arctic forms at Riviere-du-Loup, and the the occurrence of most of them recent at Murray Bay and Tadousae, and I feel confident that the names given in this list represent formsactually occurring as distinct in nature, though some of them may not be distinct specific types. I believe, however, that B. ciliatum B. glaciule, B. undatmn, B. tenur and B. Granlandicnm, are probably entitled to this rank. The others appear to me on comparison of large numbers of specimens, to graduate into one or other of the above forms. I have given in the engraved plate representatives of the more critical forms, which will enable them to be recognized. In the drift the Buccinums often part with their outer coat of prismatic shell, and in this decorticated state are very difficult to determine. Buccinofusns (Sipho) Krnyeri, Moller. Fossil — Riviere-du-Loup; Labrador (Packard). Recent — Gulf St. Lawrence and Arctic seas. First recog- nized as this species by Mr. Whiteaves. Specimens from Spitz- bergen in Mr. McAndrew's collection are perfectly similar to ours. Packard found it not uncommon at Labrador, but it seems rare in other parts of the Gulf of St. Lawrence. In some previous lists it has appeared as B. cretacenm, Reeve, which seems to be an error. Chn/sodnmus Spitzbergensis, Reeve. Fossil — Montreal (small and rare. ) Recent — Murray Bay to Gasp^ ; also Spitzbergen. and probably Sea of Okotsk. Only one specimen occurred at Montreal, and was an uuknowu DAWSON — POST-PLIOCENE. C5 m form Until T fortunately dredjied a few specimens at Murray Bay. It is a beautiful species, evidently quite distinct from C. Istnndiats. From Middcndorffs description and figure, I think it not improbable that it may be the same with his Tri- timium Schauta rlcnm, from the Sea of Okotsk. I was not aware that it had been found on our coast, except at Murray Bay, until these sheets were going through the press. Young specimens are remarkably like in form and sculpture to Fasciolaria h'gata, which is found with it at Murray Bay. Reeve's figure in Belcher's " Last of the Arctic Voyages," well represents our specimens, though perhaps a very little coarser in sculpture. Chvffsodomus tornatus, Gould. Fossil — Montreal j Quebec; Riviere-du-Loup ; Mui/ayBay; Labrador (Packard). Recent — Gaspe Bay, large specimens (Whiteaves; Labrador (Packard). This shell is not uncommon in the drift, and owing to its dense texture is generally in good preservation. It ranges from the typical C. tomatiia of Gould to Fnsus deapcctus of Lin- naeus, as described by Fabric! us, from Greenland, and shells of similar form from the British Crag are considered by S. Wood as varieties of F. ontitiuus.'^ Dr. P. P. Carpenter thinks that this and the British F. antiquus may prove to belong to one very variable species. The C. despectus is an Arctic form, and is found fossil in Canada. The C. tomotus is also fossil, and is the form now found in the Gulf. C. decemcostatus is more southern. ChrysodomHs decemcostatiis, Say. Fossil — Portland, Maine. Recent — Magdalen Islands and Gasp^ Bay (Whiteaves) ; coasts of Nova Scotia and New England. This species has not yet been found in the Post-pliocene of Canada, where it is represented by C. tornatus. There are still two opinions as to whether Say's species is identical with C. li/ratiis, Mart. - Middemiorjfii, Cooper, from the Pacific coast. The latter is variable, and graduates towards tornatus, Gould, but the living New England shells are tolerably constant in character. • The V. ilenpeclus of Reeve, however, ia a very ditfercnt species, from the Arctic regions of the North Pacific. ■\i m DAWSON — POST- PLIOCENE. Trophon scalari/onne, Gould. Fossil — Montreal; Murray Bay; Rivi^re-du-Loup ; Labrador. Recent— Greenland (Hayes) ; Murray Bay ; Nova >'cctia (Willis) ; Gaspe and North Shore (Whiteaves). It is a rare sliell in the Post-pliocene, but of large sizv, a'n" in good condition. Ti'ophoii clathr'JfKs, Linn. Fossil — Montreal ; Murray Bay ; Rivit^re-du-Loup ; also gla- cial beds of Europe. Recent — Greenland and Arctic seas generally; Labrador; Gulf St. Lawrence (Whiteaves). The allied species or variety, T. gurintri, has been found living at Ga.«(pe by Whiteaves, but not fossil as yet. 1 i I 1-4 SUB-KINGDOM ARTICULATA. Class I. — Annulata. Serpula vermiculnris, Linn. Fossil — Montreal ; Murray Bay ; Riviere-du-Loup. A small species of Serpula, apparently the above, though per- haps the determination may be regarded as uncertain. VenniUa serrnla, (Stimpson.) Fossil — Riviere-du-Loup, on shells. Recent — Gulf St. Lawrence. It is quite likely the Greenland species identified by Fabricius with Serpula triqitetra. Splochcetopterus ti/pus, Sars. Fossil — Labrador, (Packard). Recent — Labrador (Packard) ; Norway (Sars.) Spirorhif glomernta. MuUer. Fossil — Riviere-du-Loup; Labrador (Packard); Greenland (Fabr.) ; Gaspe. Spirorbis vitrea, Fabricius. Fossil — Montreal; Quebec; Rivi6re-du-Loup ; Murray Bay Very common on stones and shells. Recent — Greenland (Fabricius) ; Gulf St. Lawrence. Spirorbis Spirillum, Lin. Fossil — Rivi^re-du-Loup, on shells. Recent — Gulf St, Lawrence ; Greenland ; Fabricius. DAWSON — POST-PLIOCENii. 97 Splrorhi's suii'strontif, Moiitiiguo. Fossil — Rivierc-tlu-liOup, on the inside of shells. Recent — Gulf St. Liuvrence; Fishing Banks, American Coast (Gould.) Spirorbin rurlmitu, Montague. Fossil — Riviere-du-Loup, on shell?. This is a Spirorbis with one carina, found also in the Gulf of St. Lawrence, and possibly the same with the S. contortuplicata of Fabricius from Greenland. The beautiful Spirorhlii concelhtta of Fabricius, so common in the Modern Gulf of St. Lawrence, and also in Greenland, has not yet been found in the Post-pliocene. Class IL — Crustacea. The most abundant species arc bivalve Entomostraca, which occur in great numbers in the Leda clay, associated with Forami- nifera. The s|»efies in my collection have been kindly deter- mined by Mr. J. S. Brady, who enumerates the following: Cy there MncChcsiinji, nov. sp. " Dawsoni (Brady). " ylohiili/era (Brady). " Logan i, nov. sp. Ci/ flier idea papilUmx (Bosquet). " ptoictiildta (Brady). Ci/theridea SitrJit/nna (Jones). Cijthernra Rabertsoul (Brady). Ci/theropfcron eoniphinatiim, nov. sp. '' injintum (B., C, and R., MS.) " avgiilatum. (B., C, and R., MS.) Eiiri/there (trgus. As the paper was re-printed in the Cunadlan Naturalist (Vol. v., N. S.) it is unnecessary to notice these species further here, except to state that out of twenty-nine species of recent Cstracods obtained by Mr. Brady from uiaterial from the Gulf St. Law- rence, furnished by me, thirteen have been recognized in the Post-pliocene of Canada and Maine, though only three of these occur in the list above given. It is further remarkable that out of thirty- three fossil species from Maine and Canada, no less than twenty-three occur in the Scottish glacial beds and twenty-five are living in the British seas, while six are new species. ■I 98 DAWSON — POST-PI.IOCENf:. I*. I m i: E<> Bahniitit Ilameri. Ascfinius. Fossil — Montrojil ; St. Nicliobis ; Qiu-boc ; Rivii'redu-ljoup ; iil.-o, rddt viillii ; Russin (Miirt'liisoii) ; Groenlaud (Spongier). Hccont — (^ast of Novii Stntiji. T have obtained specimens from 31 r. Downes of Halifax, but have not elsewhere seen the species recent. It is B. luhfcmif/euHi's of lists of Scandinavian fossils and B. tidipa ol' Mullor. Tt is a widely diflfu.sed Arctic and North Atlantic species. This Acorn-shell is very abundant at lliviere du-Loup, and tine specimens are found entire, attached to stones and boidders in the Jiould"r-clay. Bnlnniis jjorcatiis, DaCosta. Fossil — Beauport; glacial beds of Europe. Recent — Gulf St. Lawrence, and coast of New England ; Labrador (Packard) ; and Arctic and northern seas generally. It is no doubt Le/jas huhoiiis of Fabricius from Greenland. Much more rare in the Post-pliocene than the preceding- species. Balanus creiiatiin, Brug. Fossil — Montreal; Quebec; Riviere-du-Loup ; St. John,N,B. (Matthew); Labrador (Packard); Portland, Maine; glacial beds of Europe. Recent — Arctic and northern seas, Greenland; Gulf St. Law- rence and American coast. It seems to be Lepas bahinarin of Fabricius. Greenland. IJitpagitriis Binikarilus f Fabricius. Fos.sil — Riviere-du-jjoup. A small speciinen in a Turrltella may be tl'e young of this common species. IJi/(is aMirctdftt, Leach. Fossil — Riviere-du-Loup. A few claws only found, but evi- dently of this common Gulf of St. Lawrenct; species. S U B-K I NG DO M V ER T E B R AT A. The vertebrate animals of the Post-pliocene are few, and may be summed up as follows : MaUottts villoms, Cuvior The common capelin is found in nodules at Green'.8 Creek ou the Ottawa. DAWSON — POST-PLIOCENE. 99 Cydopterus bimpus, Linn The lump suc'-er occurs in uodules at the same placi, Gasterostens. In nodules at the same place, found by Sheriff Dickson, It 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 Rivit^re-du-Loup, and a bird's feather io a nodule on the Ottawa. The Mammalia are represented in the marine Post-pliocene of Canada by Phoca Gricnlandica, Muller, found in the Leda clay at Montreal, and Beluga Verinontana in the same situation, and also in the Saxicava sand at Cornwall (Billings). The latter I believe to be iusntical with the modern Beluga of the Gulf St. Lawrence. In the isuperficial 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 onlv locality where fossil plants in any considerable num- ber 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 importance has come into my hands. The species recognized are : Drosera rotandi/oh'a, Linn. Acer spicatum, liamx. Potent'dla Canadensis, Linn. Gaylussacia resinosa, Jones. Populus balsami/era, Linn. i4i: "fi 100 DAWSON — P08T-PLI0CK!*!:. ili il ■ I* ■■■ Thuja occidentaUs, Linn, (found at Montreal.) Pofanwgeton perfoUatns, Linn. Equisetum, scirpoides, Michx. Carici'g and gramlnefn, fragments. Fonthalis, up. Algae. These plants occur in the marine Leda clay, containing its characteristic fossils, and were probably washed from the neigh- bouring land by streams. They indicate to Konie 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 ex- tract 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 iu the central part of Canada, near to the parallel of 46°, and an accidental selection from its present flora, though it might con- tain the same species found in the nodules, would certainly include with these, or instead of some of them, more southern Ibrms. 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° nortli. If a stream flowing to the north it might deposit these plants in still more northern latitudes, as the McKenzie Kiver 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 tlierefore safely assume that the refri- geration indicated by these plants would place the region bor- dering 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 occur- ring in Labrador, should perhaps induce us to infer a somewhat more mild climate than this." The climatic indications afibrdcd by these plants are not dissimilar from those furnished by a consideration of the marine fauna of the period of the Leda clay. DAWSON — POST-PLIOCENE. 101 Addenda to Echinodermata . Mr. T. Curry of Montreal has been so fortunate as to find in the Loda clay near that city, in addition to fragments apparently of an Ophiogh/phd, a spi-cimon probably of Ophiacinifhd spina- losd, Muller and Tr., and one of Solnsfer pupposa, 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 : Plants 10 Animals — Radiata 24 MoUusca UO Articulata 26 . Vertebrata 5 205 The whole of these, with the three or four exceptions, may be affirmed to be living Northern or Arctic species, belong- ing in the case of the marine species, to moderate depths, or varying from the littoral zone to say 200 fathoms. The assem- blage 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 typo, whereas that of the Post-plio- cene 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. t 102 DAWSON— POST-PLIOCENE. It C'nnot bo npsumed that the fauna of the older pnrt of the Ciiniidi.in Post-pliocone is difpTcnt to nny pretit extent from thtit of the more modern pnrt. Such difforeneo iis exists seems to depend merely on n priduil iimeliorfition 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 , ndoubtedly 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-bearini; 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 summevhcat 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 south- west over the lower levels of the continent. Still the cold Arctic currents entering by tiie Straits of Belle-isle and the accumula- tion of ice and snow in winter, are sutficient 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 Gasp^. South of Gaspd we have the warmer New England fauna of Northumberland Strait. I may add that .some of the peculiaritien 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 it DAWaON— r08T-PLI0CENE. 103 any of the 205 species of the above lists. This appears to me a fact of extreme Hi-riiificance with reference to theories of the mt lification of wpccies in geological time. No geolosjist donht'-- 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 bods of sediment, all testify to the lapse of time. The ehaii);es which occurred were fruitful in modifications of depth and temperature. Deep waters were shallowed, and the sea overflowed areas of land. The tempera- ture of the waters chanjred greatly, so that the geographical dis- tribution of marine aTiimals was materially affected. Yet all the Post-pliocene species survive, and this without change. Even variable forms like the species of Bnccinum and Asttirte .show the same range of variation in the Post-pliocene as in the mo- dern, 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 con- tinuously occujiied the North Atlantic area, and we have great abundance ol' tliem lor comparison both in the Post-pliocene and the modern seas. It is also iniker, on the outside of which large travelled boulders were deposited, probably by drift ice, while in the swamps within, the coal flora flourished and fine mud and coaly matter were accumulated.! A second indication of the existenc ofinitense frost in ancient geological periods, is aff'orded by the occurrence of angular frag- ments of hard rocks cemented together. Such beds of angular Iragments and chips, occur locally at various horiznis, for ex- ample in the Upper Silurian and Lower Carboniferous in Nova Scotia, and the material of which they are composed seems pre- cisely similar to that which is at present produced by the disin- tegrating action of frost on hard and especially schistose and jointed rocks. Such deposits may, I think, f lirly be regarded as evidence of somewhat intense winter cold. v., Supplementary Note. — A visit to Nova Scotia while these sheets were going through the press enables me to add the follow- ing facts: (1.) The discovery by Mr. (i. F. Matthews of shells of Tellina Groenlaudic:i in the Post-pliocene gravel at Ilorton Bluff", Nova Scotia. (2.) The occurrence of Laurentian boul- ders, probably from Labrador, in the Carboniferous region of Nova Scotia. I may specially mention a very fine boulder of Labradorite near the mouth of Carribou River, Pictou County. In Nova Scotia, however, as well as in Prince Edward Island, native stones predominate in the lower Boulder-clay, and the foreign blocks appear more toward the surface ; where also, in many cases the greater part of the blocks derived from neigh- bouring heights are collected. I had occasion often to notice the . fact, referred to above, of drift from the south as well as from the north, and also the great frequency in the boulder deposits of glaciated stoues. • Can. Nat. II, p. 6. t Acadian Geology, p. 324. PI. YII. Critical and Rare Post-pliocene Species, ( Canadian Naturalist. !0, m igh- the trora losits Drawa on Sione, by AXD TiEGGO&.C?UUi..Montreal. Z ^j-/^ CIS ■3 i /^y.^ .*% »-u.«. Group of Common Foraminifera from Montreal, (magnified.) /Wv- slomel/a cr.spa; Qumqueloadimi seminulu,,,; Polymorphina lacUa, two varieties; Entosolema glohosa and E. costata. Truncatulina lohulata. (magnified.) A^<7«w///«rt jM//4rt._Var. /r/(im/mV-<7. (magnified.) Ophioglypha Sarsii, Duck Cove, St. John, N. B. wmmmrmmmm IV. POLYZOON, BRACHIOrODS, AND LAMKLLIBRANCllIATKS (Post-pliocene — Canada.) Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 5. Fig. 7. Fig. I Fig, Fig Fig Fig, Fig, Fig, Fig. 8 Lepralia ijitadricorniita, Montreal (magnified). Kkyncfionella psittacea, Riviere-du-Loup. Terebratella Spitzbergeiisis, Riviere-dii-Loup, Mya truncata — Var. Uddeiallensis — Montreal. Mya truncata — Var. communis — Portland. Panopea Norvgica, Riviere-du-Loup. Saxkava rugosa — V,ir. Arctica — Montreal. Astarte Laurentiana, Montreal. I ■01 111 V. LAMKLMRRANCIIIATA. (Post-pliocene— Canada.) Fig. 1. Vh^. X Fig. 2. Fig. 5. Fig. 6. Fig. 9. Fig. 10. Fig. 7. Fig. 8. Fig. 11. Fig. I Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8, Fig. 9 Fig. lo. Fig. II. AfoJio/ana nigra, Portland. Mytilus edulis — (Var. flegans) — Montreal. Miuoma caharea, Kiviere-tlu-Ix)up. Alacoma Granlatuiica, Riviere-du-Loup. Macoma inflata, Riviere-du-Loup. Leda pernula — (Var. tenuisculata) — Riviere-du-Loup. Leda pernula — (Var. buccata) — Riviere-du-Loup. Leda mintita, Riviere-du-Loup. Leda (Portlandia) glacialis, Montreal. Nucula expansa, Riviere-du-Loup. Leda {YoldUt) limatula, Riviere-du-Loup. 1! 1! VI. GASTEROPODA. (Post-pliocene— Canacl.i.) Fig. 1. Fig. 2. Fig. 6. Fig. 9. Fig, 11. Fig. 8. Fig. 12. Fig. 3. Fig. 4. Fig. 5. Fig. 7. Fig. 10. FIG. 1. Ilaininea solUaria, Montreal. 2. I.epeta caca, Montreal. 3. Plates of Amiiiila Emerson ii, Montreal. 4. Trkhotropis arctka ? Montreal. 5. Vi'liitina zonata, Montreal. 6. Natica clausa, Montreal. 7. Admete riritliila, Montreal. Fig. 13. FIG. 8. 9- 10. II. 12. •3- Fnsits torttatNSf Montreal. Fusiis toHuittis (Var.), Quebec. Sip/10 Kroyeri (recent specimen, after Packard). Scalaria Graitlandka, Kiviere-du- Loup. Aiirsa Eschrkhtii, Quebec. Gasterosletis, Green's Creek, Ottawa