The remarkable frontal spine of Squaloraja has always been described as a dermal structure by those who have referred to it, and has been classed with the shagreen-granules and dentition. After the systematic position of the genus had been determined, its frontal spine was rightly recognized as identical with the spine-like frontal process in Chimæra and fossil Holocephala, with which it was formerly compared by W. Davies and A. S. Woodward. Both these processes were regarded as dermal structures by von Zittel, Jaekel, and A. S. Woodward, and treated as true ichthyodorulites, i.e. as if consisting of dentine or vasodentine. In 1890 the present writer briefly pointed out that the frontal spine of the Jurassic Chimæroid, Ischyodus avita, consisted of extremely calcified fibro-cartilage, resembling that of the so-called “claspers” of all male Elasmobranchs. The microscopical structure of these parts differs conspicuously from that of the calcified granules in the common (hyaline) cartilage of the internal skeleton, and its ontogenetic development is different.

The great group of the Ammonites (using that term in its general acceptation) is distinguished from all other kinds of chambered shells of the Cephalopod type by the complicated foliations of the margins (sutures) of the partition walls or septa into which such shells are subdivided. Though typically coiled, much in the manner of the flat pond-snail, Planorbis, there are straight and variously curved Ammonites; but all have the common character of a highly foliated “suture-line.”

Since the publication of some notes on the English Purbeckian Fishes a few months ago, the writer has been favoured by the Rev. P. B. Brodie, M.A., F.G.S., with the opportunity of re-investigating and comparing the original specimen of the small problematical fish Ceramurus macrocephalus, briefly described by Egerton from the Purbeck Beds of the Vale of Wardour. Most of the early descriptions of fossil fishes are inadequate for present needs; and no genus and species could be less satisfactorily characterized than that just referred to. A new attempt to elucidate the fossil, in the light of modern knowledge, is thus very desirable, more especially as no other specimens of the same fish have hitherto been recognized.

Leaving those local matters, there is a point of some general interest, suggested by several passages of Dr. Geikie's work, which we should like briefly to notice before laying it aside. It is in regard to those repeated depressions and re-elevations of the land which he still favours in connection with the Glacial epoch. Dr. Geikie's latest “scheme” of that epoch seems to include at least five Glacial and four inter-Glacial periods, accompanied by submergences and re-elevations to the extent of between 500 and 600 feet—the maximum being for the present restricted to that amount. Frankly, we confess ourselves unable to see the proofs for so many Glacial and inter-Glacial periods, of which, if they did occur, it would apparently be impossible—on the author's own premises as to glacial erosion—now to discover any traces. Apart from this, we might remark on the inherent improbability of such extensive oscillations of the earth's crust having happened in recent geological times, without leaving more distinct evidence of themselves than the very scanty and doubtful deposits which we have been considering.

In Professor Prestwich's important paper on the Raised Beaches of the South of England the following passage occurs: “In Torbay there are small portions of a Raised Beach near Paignton…” As on the strength of this statement the line of Raised Beaches is carried in the map round the extreme present limits of Torbay, and the hitherto universally accepted doctrine, that Raised Beaches do not occur in the softer parts of the coast-line, is thus controverted, the assertion is one of considerable importance.

Although, ever since the classical researches of J. D. Forbes on the phenomena presented by the Swiss glaciers were published, it has been recognized that glacier-ice behaves like a viscous liquid, and flows from high to low levels much in the same way as does a river of water, it is apparent that many who have interested themselves in the subject of glacier-flow, and have written rather dogmatically on the subject, have not clearly realized the nature of the phenomenon. Very contradictory and erroneous conclusions have consequently been arrived at, with the result that it is now somewhat difficult for those who have not made a special study of the subject to distinguish what may be fairly regarded as ascertained fact from that which is purely matter of opinion.

After a recent visit to Trinidad I am led to add my testimony to that of the numerous observers, who for more than a hundred years have written concerning this remarkable phenomenon.