In the GeologicalMagazine for 1877, Dec. II. Vol. IV., pp. 410, 456. there is an article on the “Geology of the Isle of Man,” by Mr. Henry H. Howorth, to which I desire to call attention. Most geologists are aware that the late Rev. Joseph G. Cumming, M.A., F.G.S., wrote a work entitled “The Isle of Man,” in 1848, and that it contains a geological description of the island. In this work, and in a papaer by the same author, published in the “Journal of the Geological Society” for 1846, vol. ii. p. 317, there is a minute description of the Carboniderous formation developed at the south of the island, near Castleton, illustrated by maps and sections.

Capping a small patch of London Clay on the highest part of Bostall Common (234 O.D.), there is a ‘drift’ that presents peculiarities identical with part of the gravel on Shooters Hill (2 miles distant) at 424 O.D.

Over the area in question the total thickness of the Chalk (where it can be measured from top to bottom, or nearly so) varies from 623 feet at Streatham to 1146 feet at Norwich, and in the latter case the topmost beds are absent; so that the full thickness, in some parts of Norfolk, may be 1200 feet or more. This figure, however, is exceptional, the nearest to it recorded being 890 at Harwich [this should probably be 895, the Glauconitic basal bed having been called Upper Greensand]. At East Horsley, in Surrey, a thickness of 817 feet has been proved, but generally speaking we find less, and over a large area 700 feet is not reached. It seems that the Chalk thins toward London (where 650 feet may be taken as about the usual thickness), not only from north and south but also from east and west. [It may be well to add the thicknesses proved by other borings outside London. These are as follows, where the borings have passed through the whole formation, from the overlying Tertiary beds to the underlying Upper Greensand or Gault:—Loughton 651 feet, Richmond 670, Cheshunt 681, Chatham and the neighbourhood 680–684, and Winkfield, near Windsor, 725. In sundry places where the topmost beds are missing we have the following:—Bushey (Herts) 686, Chartham (Kent) 735, and Coombs (Suffolk) 817, which last-mentioned should probably be over 820, for the same reason as given above, for increase at Harwich.]

Those who have carefully studied the crystalline schists cannot fail to have noticed that a community of structure—a sort of family likeness—prevails throughout any one group of rocks, while those which occur apparently at different horizons exhibit dissimilar structures. Thus the marbles associated with any group of crystalline schists are coarse or fine in grain, according to the structure of the latter. But to this rule exceptions appear, at first sight, not infrequent. For instance, in the Alps, we find not uncommonly, in that group of schists which seems to occupy the highest position, marbles which present an abnormally compact aspect. On closer examination they prove indeed to be crystalline in structure, but the crystals seem so small, the general structure so compact, that until we find them graduating into typical mica or other schists, we can hardly feel satisfied we are not being duped by infolded limestones of Mesozoic or Palæozoic age.

Kames, åsar, and minor topographical features.—Kames and åsar are usually found associated. Indeed, the one class of elevations shades into the other so gradually that it is sometimes impossible to draw the line between them. Though the kames may occur singly, they are often in ranges of several, perhaps extending for miles. Each is usually elliptical in outline, and its longer axis corresponds in direction with the range. The åsar are frequently intercepted by channels of erosion, by which they are divided into ranges of oblong hills, the direction of which is very nearly the same as that of the kames proper. In Dubuque county, Iowa, where these features have been most thoroughly studied, this direction is about S. 75° E. Within 40 miles south-west from there the direction changes to abut S. 45° E., and in the next 50 miles the direction becomes a trifle west of south; and this is the general direction over the greater part of the region examined.

Sp. Chars.—Tooth bidentioulated with a re-entering angle between the denticles; sides sloping down to the lateral angles; anterior profile convex; posterior profile concave. The most prominent portion of the anterior surface is at the centre of the inferior margin of the crown, where it becomes bowed-out, whence the surface gradually recedes to the cutting edge of the crown on the one hand, and more rapidly towards the root on the other.

Knowledge about marine reptile diversity and disparity during the Late Jurassic is increasing. This contribution describes marine reptile skeletal elements (ichthyosaur and plesiosaur) from Kingofjeld mountain in NE Greenland. The assemblage is early Late Oxfordian (Late Jurassic) in age, and consists of c. 100 disarticulated skeletal elements. The location is of biogeographic importance as it was at the time situated between the Boreal realm and the Tethys Sea and is promising in terms of future prospecting.

The question of the origin of the Archæan rocks is one of such great interest that it will not be thought unimportant on the one hand to record any facts that may bear upon it, and on the other to examine somewhat severely all the evidence that may be from time to time brought forward on the subject. Among the facts which may be adduced in support of the view that the Archæan rocks are altered sedimentary strata, the occurrence of breccias and conglomerates may well claim a foremost place; and a vast amount of superincumbent theory must rest on a very shaky foundation if there be any doubt whether some of those ancient fragmental beds be true conglomerates or not. The manner of occurrence, the mode of formation, and the character of pseudo-breccias and pseudoconglomerates become therefore questions of first importance.

It will, no doubt, be admitted by all, that it is highly conducive to the advancement of any science, that some one of its votaries, more courageous than his colleagues, and endowed with a more generalizing turn of mind, shall, by the comprehensive and exact study of accumulating observations, endeavour to elevate himself above the level of the more plodding but invaluable collectors of facts, by attempting the arrangement and organization of such data, and the deduction therefrom of the laws which regulate their existence and govern their movements.

A small mass consisting of three intrusions of fine-textured acid rocks occurs within the basaltic agglomerates of the Kilchrist Vent of Tertiary age. One of the intrusions comprises flow-layered rhyolite and ignimbrite. It is thought that the rock-types represent two distinctive eruptive waves. A form of ovoidal structure not seen elsewhere in the Kilchrist area occurs in another rhyolite intrusion.

The descriptions of two of the species enumerated in my paper on the Tertiary Fossils of the West Indies having been accidentally omitted, the defect is now supplied.

IN December of 1932 a paper was published in the Geological Magazixe (1) dealing with a number of Tertiary orbitoidal foraminifera from N.W. Peru, which had been presented to the British Museum. During the examination of the material it was noticed that there were no forms present comparable to Lepidocyclina R. Douvillei Lisson in regard to the size of the embryonic apparatus, although a large number of the specimens had been collected from Lisson’s type locality. All the forms examined from Mount Organos and from contemporaneous deposits in the neighbourhood proved to have a much smaller apparatus and were found to be identical with Lepidocyclina peruviana (Cushman) when compared with the type material in the Sedgwick Museum, Cambridge.

In the former notes “On the growth of soil,” I omitted to speak of the labours of the ants—these workers, although such pigmys in this country, and, therefore, compared with the earth-worms, less capable, individually, of work, are so numerous and energetic, that in the special places to which they resort, their yearly work is much more conspicuous than the annual worm-work; but the animals operate in different places, for while the earth-worm luxuriates in rich highly-cultivated land, the hill-building-ant loves a dry, sandy or peaty soil. In the spring the ants may be observed beginning their work, and from that time they carry on their operations all through the summer, to the late autumn, or early winter. On a moor they raise hillocks scattered promiscuously about over the ground, getting closer and closer together as the colonies increase. But where the ants are most useful is in places where crags and large stones are mixed up with patches of sandy peat. In such a locality they will always build on a rock, the foundation of their habitation being at its junction with the soil. These ants seldom raise their structures as high as the moorland ants, but they make up in extent for absence in height, and by this means the rocks are gradually covered with soil and vegetation; for, on account of the season of the year at which they build, the growth of the plants keeps pace with the formation of the ant-soil, and protects it in a great measure from “Meteoric abrasion.” During the winter, however, the shape of the ant-hills is somewhat modified, but the matted roots of the plants preserve the major part of the soil which will thus remain, forming an envelope for the rock.

On the Graptolites of Gothland (Om Gotlands Graptolither). By G. Linnarsson. Ofv. af. Kongl. Vetens. Akad. Förh.; 1879, No. 5, pp. 12.

The island of Gothland, so rich in all other Silurian fossils, is remarkably poor in Graptolites. Angelin and Lindström simply noted the fact of their presence, but did not attempt their identification. At Dr. Lindström's suggestion, Mr. G. Linnarsson here describes and figures the two species that have been procured from these strata, from examples now in the Riks-Musei of Stockholm.