Disk small, membranous, often indistinct, a character which separates this genus from Ophiura. Rays very long, slender, depressed, formed of circles of plates, four in each circle; the lateral plates are the largest, most prominent, and provided with long spines; the basal plates are small and spiniferous, and the dorsal smooth and without clothing. Mouth plates small and triangular. All the species known have been found in the Jurassic rocks.

The present communication is the result of the examination of a considerable number of small Silurian Corals, from Wenlock and Colwall, made as long ago as 1883, and it was written with the intention of its being communicated to the Geological Society. I very much regret, however, that circumstances have arisen which render it extremely difficult, perhaps impossible, for me to place myself aga in incommunication with that body. The paper appears therefore in the pages of the Geological Magazine, a medium for publication which I hope from time to time to have recourse to.

So little is known of the extension through later Mesozoic deposits of Selachian teeth belonging to the familiar type of Acrodus, as represented in the Lias, that any additional evidence upon the subject is invested with considerable interest. It is impossible, of course, from these isolated relics, to determine whether the original Sharks were as closely allied as the resemblances in their dentition might at first lead one to suspect;inone case, indeed, it has been proved that the complete fish differs much from the Liassic species; but the persistence of the dental type is at any rate of some significance, and it may therefore be acceptable to offer a few notes upon the undescribed Jurassic and Cretaceous Acrodonts preserved in the British Museum. These specimens furnish evidence of at least two new specific modifications, and they are also suggestive of novel points in regard to some of those already known.

From Mr. Newton's letter in the February Number of the GEOLOGICAL MAGAZINE, I am inclined to think that he has somewhat misunderstood my meaning where I referred to the fauna of the Norfolk Forest Bedinmy paper in the December Number. Prof. Hughes had stated in his paper that the bones from the caverns “belong to the newer group of animals found elsewhere in undoubtedly Post-Glæial river deposits.” As Mr. Newton admits “that most of these species have been found in the Pre-Glacial Forest Bed of Norfolk, and it is probable that others of them will yet be found,” it is clear that I was correct in my contention that “a very large proportion of the animals occur in the Norfolk Forest Bed.”

The Gelinden Flora, described by Saporta and Marion (Mém. de l'Acad. de Belge, t. 37; and Révision de la Flore Heersienne de Gélinden, ibid., t. 41), has assumed an immense importance owing to the fact that it alone, among Tertiary fossil floras whose age is definitely ascertained on stratigraphical and palæontological grounds, contains certain remarkable types of leaves which are common to it, to the inter-basaltic beds of GlenarminAntrim, and to Atanekerdluk in Greenland. Two of these are long lanceolate leaves, with three or more parallel mid-ribs.

The chief object of this paper is to describe an unmapped outlier of Bagshot Sand, inwhich the pebble-bed, frequently met with at this level, exhibits an extraordinary thickness and compactness. It is situated at Bearwood, on the estate of John Walter, Esq., who has kindly given me every facility for investigating it. The extent of the outlier may be said to coincide approximately with the space enclosed within the 250 foot contour-line of the Six-Inch Ordnance Survey Map.

When I noticed this species in the January Number of the GEOLOGICAL MAGAZINE (pp. 1–10, Plate I.), I had not prepared a figure of the original specimen from the Hope Collection at Oxford, which had been kindly lent me by Prof. J. O. Westwood for that purpose.