above the chord is sometimes as much as an inch and three quarters. It is often somewhat pointed, and the highest part is not always in the middle between the parallel side ridges (Fig. 4). The concave side of the curve is always on the steeper side of the tranverse ridges.

There runs along the track a ridge intermediate between the two parallel side ridges, (Figs. 3-4-5), and though it is not so conspicuous as these, it is seldom altogether wanting, but appears to be, most obscure when the transverse ridges, or rounds of the ladder, are straight. This intermediate ridge does not keep parallel with the side ridges, but occasionally runs in sinuous sweeps from within an inch and a half of one side (Fig. 5) to the same distance

ges. The course of the intermediate ridge appears in general to coincide with the successive most salient parts of the transverse ridges when these are curved, but this is not always the case (Fig. 4). The intermediate ridge appears most conspicuous where it crosses the transverse furrows, yet its crest or line of summit seems to undulate with the ridges and furrows, though not to so great a degree.

The inner flanks of the side ridges appear to be continuously even surfaces, making an angle of 155° with the plane of the intermediate spaces, and against these sloping flanks the surface of the transverse undulations forms a decided, though very obtuse set of angles, just like waves rolling along an inclined plane in the direction of its strike. The side ridges are rounded at the top, and while their exterior flanks are more precipitous than the interior

My naturalist friends to whom I have exhibited the specimens, appear disposed to consider the tracks those of some species of gigantic mollusc, and I am given to understand there is now living some small mollusc, whose track presents a series of transverse ridges and furrows, without, however, the longitudinal ones. From the resemblance of the track to a ladder, the name proposed for it is Climactichnites Wilsoni, the specific designation being given in compliment to its discoverer, Dr. Wilson.

ARTICLE XL.-Notes on the Coal Field of Pictou. By H. POOLE, Esq., Superintendent of the Fraser Mine.

(Communicated to the Natural History Society by Principal Dawson.)

[The facts contained in the following communication, may be regarded as supplementary to those noticed in my Acadian Geology, and in a paper by Mr. Poole and myself, published in the proceedings of the Geological Society. The coal measures of the Albion mines, dipping to the N. E., at an angle of about 189, contain the great main seam, 36 feet in thickness, and 157 feet below this the deep seam, a bed of inferior but still great thickness. To the north-west these coal measures are apparently cut off by a great bed of conglomerate dipping north, beyond which occur other coal measures, also with northerly dip. For rea

sons stated in the publications above mentioned, I regard the great conglomerate of New Glasgow above referred to, not as a recurrence of the Lower Carboniferous conglomerate, but as a bed of the date of the coal formation, a contemporaneous shingle beach, which shut off the Albion Mines coal area, and occasioned its exceptional character. In connection with these facts and views, Mr. Poole's observations bear on the following points; (1). The character of the coal measures below the deep seam, previously little known. (2). The sudden bending of the outcrops of the coal seams to the southward, west of the Albion Mines, so that they assume northerly dips for some distance, though they appear to return to a N. E. dip further to the westward. (3). The occurrence of a narrow and abrupt synclinal immediately to the N. E. of the Albion Mines, succeeded by an anticlinal, near the axis of which in this locality is the outcrop of the great conglomerate. (4.) The results of explorations made in the measures north of the conglomerate, confirming apparently the difference of these in character, from the great coal measures south of the conglomerate. (5.) The frequent occurrence, as at the Joggins, of scales of fishes, bivalve shells, Cypris and Spirorbis in connection with the beds of "Oil Shale," and coal. I have added a notice of these fossils to Mr. Poole's paper. J. W. D.]

The operations of the Fraser Oil Coal Company were carried on during the past year in a seam of coal and bituminous shale situated upon the Coal Brook, and underlying the seams of bituminous coal worked by the General Mining Association.

The respective out crops of the deep seam and the Fraser oil coal being 528 yards apart on the surface, and the general dip N. 42° E., at an angle of 18 degrees, or 1 to 3, the oil coal will underlie the deep seam 528 feet in perpendicular section.

It is situated about 60 feet below the tabulated section given in Haliburton's History of Nova Scotia, which distance is chiefly occupied by strong bands of sandstone, whose actual thickness is not yet proved, thin soft shales with bands of ironstone, Stigmaria with Sigillaria and a few detached fern leaves (Neuropteris), in such soft shale that I have not been able to preserve any good specimens. Immediately above the oil coal are fourteen inches of bituminous coal, but only the lower four inches are of good quality, the upper part being of a soft friable nature, producing a great deal of ash.

The oil coal has a smooth regular parting at top, next to the

coal, as well as at the bottom, next to the oil shale, but varies in its thickness from a few inches up to twenty. Throughout its entire thickness it has a curled and twisted structure, many of its fractures look like the casts of shells, and the sharp edges are polished and stickensided. No fossils that I am aware of, have hitherto been found in the "curly" oil coal, but scales of calcareous spar are often met with in the joints. The oil shale next below is nearly two feet thick, of a homogeneous character with a shaly cleavage of various thicknesses. In this band a few scattered ganoid scales have been found, and two or three varieties of lepidodendron beautifully preserved, also leaves of Cordaites of various lengths and breadths, which have undergone so little change, that pieces from four to six inches long, and in breadth about a quarter of an inch, could be removed when the shales were first split, and were so elastic that they could be bent considerably without breaking. In the argillaceous shales below are bands containing innumerable Cypris and Spirorbis shells. The crop of a small seam of coal which must underlie the oil coal about thirty feet is seen in the brook. There are surface indications of the coal measures continuing for a considerable distance towards the south-west, and this has been proved to be the case by Robert Culton, who is opening up a seam of coal upon his farm upwards of one mile and a quarter distant, to the rise of our mine, which will be alluded to hereafter.

There are numerous small faults running across the measures in the Fraser Mine, which are uniformly downthrows to the west: and I may here mention that I observed some years ago in the deep seam several faults of from four to ten feet each, which could not be found in the main coal workings above (the distance between the two seams is 157 feet), which shows that the disturbances must have taken place previous to the formation of the main coal seam ; a fact which should not be lost sight of in investigating this extensive coal-field.

The oil coal has been traced from the Fraser Mine eastward as far as the main road, but from thence down to the East river there is a great thickness of drift which appears to have cut off the crop. It has not been traced on the east side of the East river, and, although a bed of oil coal has been found and worked by A. Patrick on the McLellan Brook, I am inclined to think it is not a continuation of the same seam, but-from the fossil-sof one much lower down in the coal formation.

To the west the oil coal has been traced for half a mile, with a line of strike parallel to the deep and main seams, or a course about N. 500 W. to the top of the hill, where there is evidently some disturbance, the sandstone appearing on edge and dipping in different directions. It was next found in the McCulloch Brook at a considerable distance up the brook, or to the south of the general line of strike, where it was found to dip 13 degrees, N. 67° W. The oil coal is here of a much richer quality than at the Fraser mine, and from the free way in which it burns, throwing off stars or sparks of light, it has been named Stellar coal to distinguish it, and an adit is now being driven in it back towards the Fraser mine. It also varies in thickness from two to twenty inches, and as the coal roof is regular, I should infer from the twisted appearance of the oil coal that it has been in a pasty state and subjected to great and unequal pressure.

1600 tons of two qualities were shipped to Boston, in 1859, from the Fraser mine, the top seam of curled coal yielded in the D retorts 63 gallons per ton, and the second quality of shale, 45 gallons per ton of crude oil. A small sample of the stellar coal gave 77 gallons per ton of crude oil. I am told that the rotating retorts produce 30 per cent more oil from the same material than the D retorts. Some picked samples from Duncan McKay's adit tried in Boston gave 199 gallons per ton. Torbane Hill mineral yields 125 gallons; the Albertine coal of New Bruns wick gives 100 gallons, and the Lesmahago Cannel of Scotland gives 40 gallons per ton of crude oil.

Professor How of Windsor has sent me the following analyses of these coals.*

Two small trial holes have been made by Mr. R. Culton in the bank of the McCulloch Brook at 124 chains distance from the

* Professor How has since published these and other analyses in a paper in the Ed. New Phil. Journal, and Silliman's Journal.