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anything satisfactory could be determined. The examination of the district, however, shows that the conclusion of Dr Singer, though correct theoretically, is really incorrect; for it is evident at the various junctions of the formations, as in the Newton, Hartfell, or Frenchland Burns, that the unconformable sandstone rests immediately on the upturned edges of the Silurian strata.

The occurrence of the black, coal-looking, anthracitic Silurian shales in many localities, has led to the belief that coal existed in their neighbourhood, and has caused several abortive attempts to reach it to be made, in opposition to the published opinions of the Busbys, Jameson, and Singer. It is remarkable that landed proprietors in every Silurian region have been induced to spend their money in vain attempts at searching for coal, where these anthracitic shales occur, on the recommendation of empirics, and generally in opposition to the published or known testimony of scientific men.

The Trap Dyke.

The Trap Dyke has been quarried for some years at a point where it projects on the surface near the summit of the Lochhouse Hill. It supplies the bluish stone which has been extensively used in the recent buildings in Moffat. Its relation to the strata, through which it is intruded, can be best seen in the bed of the Evan, a little above Longbedholm Cottage. Its direction is N.W. by S.E. Beyond the point where it crosses the Evan, it may be traced in a N.W. direction until it crosses the line of the Caledonian Railway. In the opposite direction it has been quarried on Evan road side. It pushes out into considerable prominences in several places on the Coates Hill. It is also quarried, as has been said, on the Lochhouse Hill, and again in a plantation on the farm of Woodhead. Mr David Stewart has observed quarries in it in Dryfesdale and Eskdale. I believe it to be the same dyke that occurs again at Langholm.

It is a compact, fine-grained greenstone, distinctly crystalline in the centre, and becoming compact and amorphous at the edges. It is 32 feet wide at the quarry on the Evan road.

It is difficult to determine positively the age of this dyke from the strata in this district. If the position of the sandstone on the sides of the Coates Hill tells, as it seems to do, that this hill was elevated subsequently to the majority of the hills around, then this trap dyke must be either a contemporaneous or subsequent intrusion.

The Boulder Clay.,

The boulder clay is a light-coloured clay, containing small boulders, many of them having the rubbed and polished appearance peculiar to and common in this deposit. It covers. the Gallows Hill. The only section of it that I have seen is in a gully in a narrow plantation running down from the Old Well road; but this is of no great depth. It is exposed in the Whins, where it is sometimes dug for use in the village. The shoulder of land between Moffat and Annan Waters, forming Aikrigg farm, seems to consist also of boulder clay. A few of the large boulders here lying on the surface are from the Trap Dyke, which passes through the fields in this locality, although it cannot be detected on the surface.

Gravel, here and there intermingled with sand, occupies the bottom of the valleys. At Granton, on the Dykefarm and in other localities, it exists in considerable masses. presents no peculiarities requiring particular notice.

It

The sides of the hills are covered with angular shivers― fragments of the underlying rocks-mixed with soil.

Peat is abundant in the district. The flat summits of the mountains are covered with hill peat formed of, and now forming from, the mosses, lichens, heather, and rushes which cover the hills. It is a friable peat, wanting coherence, and is generally intersected by innumerable gashes (moss-hags), formed by the draining of the rain-water. The peat in the low grounds, as at Lochhouse, contains the trunks of trees of species similar to what still grow in the district,—fir, hazel, and birch.

391

Wednesday, 23d April 1862.-JAMES M'BAIN, M.D., President, in the Chair.

The following gentlemen were elected members of the Society :

Peter Waddell, Esq., Claremont Park, Leith; James Crichton Browne, M.D., Dumfries.

Committees were appointed for special investigation during the sum

iner.

The following Donations to the Library were laid on the table, and thanks voted to the donors :

1. Bibliographia Librorum Entomologicorum in America Boreali editorum. Auctore Guil. Sharswood.-From the Author. 2. Jahrbuch der Kaiserlich Königlichen Geologischen Reichsanstalt 1860. XI. Jahr

gang, Nro. 2. April-December. Wein.-From the Imperial Geo

logical Society of Vienna. 3. Report of the Commissioner of Patents for the year 1858. Agriculture. Washington, 1859. 4. Report of the Commissioner of Patents for the year 1857. Agriculture. Washington, 1858. -From United States Patent Office.

The Communications read were the following:

I. Observations on the Phocide of the Greenland Seas. By JOHN WALLACE, M.D. Edin. (Communicated by ROBERT BROWN, Esq.)

In this memoir, Dr Wallace described minutely the characters of the four species of seals which form the source of the fisheries in the Arctic seas, and entered at length into an account of their habits and history-a subject regarding which little or nothing is known, and that (from the remote and almost inaccessible regions which the animals frequent) in a very contradictory and confused state. He prefaced his observations on the species with some general remarks on the anatomy and physiology of the group. The length of the intestine, according to his measurement, varies between fifty and sixty feet. The livers have no poisonous properties, as has been alleged regarding those of Nova Zembla and the Southern seas. (Anson.)

In the young seals the lymphatics of the neck are subject to a disease, which appears to be analogous to, if not indeed true scrofula.

Many theories have been adduced to account for their capability of remaining so long below the surface of the water with impunity, though that of Buffon and the physio

VOL. II.

3 E

logists of his time, and of Blumenbach and Houston in more modern times, are the most celebrated. The first is untenable, as Dr Wallace found the foramen ovale unclosed in only one of the many hearts which he examined; and in regard to the venous sinuses said to have been found by the latter anatomists in the liver and neighbouring parts, he had seen nothing which deserved the name. The venous system on the whole, and not in any particular part, unless in the vena cava, from the pressure exerted on its walls, is greatly enlarged, but this arises from the great quantity of blood these animals possess. Moreover, supposing these sinuses to exist, they could not contain the full quantity of blood that may return in that period from the capillary system. Their power of remaining so long below the water is to be referred to a cause physiological, and not structural.

Their expertness in swimming is not acquired from birth, but only as an innate instinct. On first taking the water, they swim about in the smooth pools among the ice, and then swimming slowly and quietly about, seldom remaining longer than a few minutes below the surface. This training, coupled with the enormous quantity of blood which they contain, and their slow respiration, will account for their capability of enduring pro tempore a sub-aquatic life.

1. Phoca Grænlandica, Mull. (The "Saddleback" of the northern sealers.)

The most common length is five feet and a-half. The author had noticed some which differed so much from the typical specimens as to have led to the belief by the sealers of their being different species.

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Lepechin's description of his Phoca oceanica is about the best description of the present species extant. The colour of the young at birth is a pure white, which gradually assumes a beautiful yellowish tint; they are then called white-coats," and they retain this colour until they are able to take the water (when about fourteen or twenty days old). The colour of their hide changes at the same time to a dark speckled and spotted hue. Such are denominated "hairs" by the sealers. This colour gradually changes into a dark

bluish colour on the back, while on the breast and belly it is of a dark silvery hue.

Young seals retain this appearance throughout the summer, and are termed "blue-backs." The next and last stage is into the mature coats of the male and female adult. Three summers will be nearly the time required for these changes. The "saddleback" has a wide distribution, influenced greatly by the nature and distribution of the ice, and performs a migration north in the spring, and south in the winter. Dr Wallace gave numerous additional details regarding its natural history, from personal observations in the Greenland seas during the year 1860.

2. Phoca leonina, O. Fab. (The "Bladdernose" of the English sealers.) No sealers, as far as he was aware, had ever seen such a seal as that described by Otho Fabricius in his "Fauna Grænlandica," viz., with a straight line of brown on its back, as that author describes this seal in its second year. Crantz and Fabricius disagree regarding the localities which it frequents; the one affirming that it is found mostly on great ice islands, where it sleeps in an unguarded manner, while the other states that it delights in the high seas, visiting the land in April, May, and June. Both authors are correct, though not in any exclusive sense. The "Bladdernose" is found all over the Greenland seas from Iceland to Spitzbergen. and Nova Zembla.

3. Phoca hispida, Mull. (Phoca fœtida, O. Fab. Netsik of

Greenlanders.)

The smallest seal in the Greenland sea. It is chiefly seen, and taken as a curiosity, by the whalers, who call it the "Floe-rat," as it is always found on floes of ice, or quietly swimming about in the floe waters.

They appear to be confined to high latitudes, and especially to the parallels of 76° and 77° north latitude in the Greenland and Spitzbergen seas, and it is in those latitudes that the whalers find them.

4. Dr Wallace described a fourth species of seal, which forms a considerable source of the Greenland seal fishery,

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