The history of this gigantic rodent began to be written in 1809, when M. Gothelf Fischer described a skull from a sandy deposit on the borders of the Sea of Azof, to which he gave the name of Trogontherium. Since then, at varying intervals, to the present time, new chapters have been added to this history by both Continental and British workers, describing specimens of a more or less fragmentary character which have from time to time been discovered. The English specimens have been chiefly obtained from the ‘Cromer Forest Bed,’ that rich and remarkable series of beds occupying a position in time between the Crags and the Glacial deposits of East Anglia. The ‘Forest Bed’ specimens were first made known by Sir Charles Lyell in 1840, but were more fully described by Sir R. Owen in 1846 and referred to Fischer's Trogontherium Cuvieri. It will not be necessary at this time to refer specifically to each of the additions to our knowledge of this animal or to detail the varying opinions as to affinities and nomenclature, as these particulars will be found in the Memoirs of the Geological Survey of the United Kingdom. Although most of the British specimens of Trogontherium Cuvieri have been found in the ‘Cromer Forest Bed’ a few examples have been met with in the Norwich and Weybourn Crags. The smaller species, which has been called T. minus, was obtained from the nodule bed below the Red Crag of Felixstowe, and an incisor tooth from the Norwich Crag was referred to the same species.

Among the collections received from the Egyptian Survey for determination is a number of vertebrate remains, chiefly mammalian, from the Wadi-Natrun, whence they were obtained by Captain Lyons, the Director-General of the Survey, and by Messrs. Beadnell and Blanckenhorn, members of his staff. Last year, on my return from Mogara with Mr. T. Barron, I was able to collect for a few hours on the hill called Gart-el-Moluk, from which most of these fossils were obtained, and found a few additional fragments. Finally, Dr. Studer, of the Berne Museum, has very kindly lent me the collection he received from the same locality, and has himself described in some detail.1 I believe, therefore, that a great part of the specimens from this locality are now in my hands. Unfortunately in most cases the remains are in a very fragmentary condition and little can be made of them, but there are a few well-preserved teeth and limb bones which indicate the existence of a fauna of considerable interest, and are sufficient to show that the locality will probably yield good results to a systematic search. At present the collections include remains of a small Hippopotamus, a Hipparion, a small pig-like animal, and various Antelopes. In the present note I propose to give a short account of the more important of these specimens.

The Isle of Purbeck possesses numerous points of geological interest, and its coast scenery has been celebrated, in conjunction with that of Lulworth, by many writers and artists. The classical work of Sir Henry Englefield, assisted by Webster, in the early part of the last century, served to make known some of the most interesting features of the coast, such as are more or less obvious to all who venture to sail beneath its cliffs. Of late years the geology of the Isle of Purbeck has attracted the attention of the officers of the Geological Survey, and has come in for a considerable amount of description at the hands of H. B. Woodward, Aubrey Strahan, and Clement Reid, in their respective departments. The zones of the Chalk in this region have also been admirably described by Dr. Rowe and his coadjutors, mostly from coast sections.

There are eight specimens (a 314) to which Salter gave this name. All are from the Wenlock Limestone of Dudley, and belong to the Fletcher Collection. Only one shows any part of the upper surface.

The Himalayas, with the help of that singular replica of the more mountainous region known as the Salt Range, have afforded to the palæontologist, in one place or another, a fairly good series of the several Palæozoic horizons.

In my “Notes on Drepanaspis Gemündenensis, Schlüter,” published in the Geological Magazine for April, 1900 (pp. 153–159), I described a paired plate of a trapezoidal form occupying a position on each margin of the under surface of the head, a little behind the mouth, and to which I gave the name ‘sensory’ plate, as it is perforated by an opening which, if not orbital, evidently marks the place of an organ of sense of some sort. With this opening I also identified a depression seen in some specimens in a similar position on the dorsal aspect, and came to the conclusion that its position was marginal, being seen in some specimens on the ventral and in others on the dorsal surface of the head. I was also much puzzled to find that in some specimens this pit or depression seemed to have a floor, covered with tubercles like those of the rest of the surface, a condition which apparently militated very decisively against the idea of its being an orbit.

Having some time since been favoured by Mr. and Mrs. Coomáraswámy (Miss Ethel M. Partridge) and Mr. Joseph G. Hamling, F.G.S., of Barnstaple, with the loan of their collections of Culm Trilobites from Coombe Wood, etc., near Barnstaple, I feel it incumbent to add a few notes to those already published by me in the Appendix to Messrs. Hinde & Howard Fox's paper (Quart. Journ. Geol. Soc., 1895, vol. li, pp. 646–649, pl. xxviii, figs. 1–8).

The skeletou of a Hippopotamus Madagascariensis, Guldb., in the British Museum (Natural History) has been mounted from materials excavated by myself in the marshes of Sirabé (Central Madagascar) during the year 1895. The skull, lower jaw, several of the vertebræ, and presumably some other bones belong to the same individual.

The common English classification of the Palæolithic Period into the epochs of the River-Drift Men and the Cave Men hardly conduces to clearness of thought. The implements of the River-Drift men are often found in the caves, and those of the Cave Men are very common in the river drifts. Although the caves and rock shelters bring us down to a later period than is usually represented in the river drifts (there appear to be exceptions to this), yet the general succession in the two classes of deposits is the same, and they cannot be separated.

Salter's original specimen comes from the Wenlock Shale, Builth Bridge, and was described (Salter, loc. cit.) as having “much narrower whorls than Phr. nautileum.” The specimen consists only of the greater portion of the outer whorl, including the body-chamber, and it shows the aperture and ornamentation very well preserved. It agrees with Blake's species Tr. striatum in shape, rate of increase, characters of body-chamber and aperture, degree of obliquity of the transverse ribs, their absence on the body-chamber, the fine lines parallel to them on the rest of the whorl, the epidermids, and the shape, position, and distance apart of the septa. The stratigraphical horizon on which it is found is also the same, and there can be no doubt that the species are identical, as they agree in all the essential characters and even in every minute detail.

The accompanying section (Plate XXII) will serve to show, diagrammatically (after Dr. Ami), the succession of the Cambrian rocks at Mount Stephen and Mount Field, B.C., and the position of the Trilobite bed on the flanks of Mount Stephen (referred to on p. 503) from which Mr. Whymper's collection was obtained.

In the year 1886 the late Dr. G. M. Dawson gave an account of a syenitic rock, rich in a beautiful blue sodalite, which he had discovered when exploring the district near Hector Pass, on the watershed of the Canadian Rocky Mountains, and an analysis of the mineral was afterwards published by Professor Harrington. The place was visited last Summer by Mr. E. Whymper during his examination of the district south of the Canada Pacific Railway, when he collected a number of specimens, which he showed to me on his return. The rock is hardly less beautiful than lapis lazuli, and as no description of its microscopic structure has been published, as far as I can ascertain, I give the results of my examination, together with a condensed account of its mode of occurrence. I am much indebted to Mr. Whymper for placing his specimens at my disposal, to Mr. L. Fletcher, Keeper of the Mineral Collection in the British Museum, for the opportunity of examining specimens of sodalite rock not in my own cabinet, and to Mr. L. J. Spencer, of that department, for giving me his kind assistance and valuable references to papers about the mineral.

This species is fairly common in the Alveolina-limestone of the present series, occurring both in the powdered rock and in thin sections. For the previous occurrences of the species in Egypt see Geol. Mag., 1900, p. 7.

There is only the one poorly preserved and imperfect specimen in the Woodwardian Museum on which Salter founded this species. It comes from the Wenlock Limestone of Dudley and belongs to the Fletcher Collection. Salter says of it (a 827): “Strongly costated and marked with lines of growth which decussate the ribs. Twice the size of the common Ludlow species.” The material is so poor that the specific description must necessarily be incomplete.

The interesting paper on “The Connection of the Glacial Period with Oscillation of the Land,” by Dr. Holst, while reinforcing the quite probable theory that areas loaded with glacial ice sink under the burden, and after the ice has been thawed rise again, goes out of its way to deny the existence of Interglacial periods, probably with the idea that there was only one important sinking and rising in the Pleistocene, and hence no opportunity for Interglacial times. However that may be in Sweden, the evidence in favour of at least one important Interglacial period in North America is too strong to be set aside for any mere theory.

Several Arachnida allied to Eophrynus prestvicii have been discovered in beds of Carboniferous age. Of these the only species known to me as belonging unquestionably to the genus Eophrynus that has been properly described and figured is the form from Silesia named Eophrynus (in error written Euphrynus) salmi by Stur. The type is 27 mm. in total length, the prosoma being 8 long and the opisthosoma 19 long and 14 wide. The last-named region is thus considerably narrower in relation to its length than it is in E. prestvicii. Apart from this, it is noticeable that the admedian dorsal tubercles, except on the second and third terga, are much smaller than the laterals.

The fossils described by Mr. Hudleston, F.R.S., in Part II of this paper, were found by Captain B. E. N. Gurdon, C.I.E., D.S.O., Assistant Political Agent, Chitral, on the right bank of the Chitral river, between Chitral and Mastuj. The spot where they were collected is indicated by a small cross marked on the accompanying sketch-map (Fig. 1), which has been based on the map of the Pamirs compiled under the direction of the Right Hon. G. N. (now Lord) Curzon to illustrate a paper by him published in the Journal of R.G.S. of 1890. My son, Major A. H. McMahon, C.S.I., C.I.E., F.G.S., in company with Captain Gurdon, visited Mastuj in October, 1900.

The genus Peripristis was established in 1870 by Orestes H. St. John for the reception of two species of Carboniferous fish-remains, one of which had been previously described by Newberry & Worthen under the name of Ctenoptychius semicircularis, and was selected as type of the new genus. The other was known in collections and printed catalogues under Agassiz's manuscript title of Pristodus falcatus, but this name did not acquire validity until J. W. Davis adopted it in his monograph of 1883. As there can be no question that the two species are congeneric, it follows that St. John's appellation of Peripristis has priority over Davis' term, and the type species becomes P. semicircularis (N. & W.) instead of P. falcatus, Davis.

The species Nautilus robustus was founded by Dr. Foord and myself upon three examples in the British Museum collection, bearing respectively the register numbers 37,010, 37,005, and C. 1,944.