Through the kindness of Dr. Flett there has come into my hands an interesting boulder of nepheline-syenite belonging to Sir John Murray, dredged during the expedition of the Michael Sars(1) from the Atlantic Rise at a depth of 1,750 fathoms at a place about 150 miles south-west of the south-western corner of Ireland (Station 95 of the Reports of the Michael Sars Expedition). The slices examined were slides Nos. F 2092 to F 2095 from the Geological Survey Collection and two belonging to Dr. Peach. It is a boulder of remarkable freshness, and so entirely unlike any other specimen as yet recorded from the floor of the Atlantic that the question of its origin is of some interest. The fact that no other fragments of the same type were obtained in this dredging militates against the view that it is part of a mass in situ on the sea-bottom. Its companions from the same station, and in fact all the specimens collected by the Michael Sars, have been recognized by Dr. Peach and Dr. Flett as similar to rocks occurring commonly in Ireland, the North-West Highlands, and the Southern Uplands of Scotland, and not one among them is closely related to the nepheline-syenite. Bocks of Irish types have also been described by Professor Cole and Mr. Crook (2) as a result of earlier dredgings of the Atlantic floor, and again no specimen has been found remotely resembling the subject of this paper.

On looking over a small collection of rodent remains from the Pleistocene cave-deposits of Crete, Mr. Oldfield Thomas drew my attention to one specimen which appeared to be of special interest. It consists of an imperfect right mandibular ramus still in the matrix, and which contains the base of the incisor in a fragmentary condition, and the first and second molars in a perfect state of preservation. The third molar is missing. This specimen was obtained from a cave-deposit on the south side of the little bay of Sphinari on the west coast of Crete. The deposit is almost totally destroyed and is still partially submerged; a few fragmentary remains of an ungulate were also observed and appeared to be those of the Cretan deer Anaglochis cretensis of Simonelli, which occurs in so many of the cave-deposits of the island.

Zoarium small, highly conical, slightly compressed in one direction, very fragile.

Zoœcia rather bluntly hexagonal, subradially arranged in straight rows which from time to time diverge to admit a new row, length ·35–·4mm., width about the same; the area varies from distinctly elliptical to practically circular; maximum length ·33 mm., breadth ·3 mm.

In two previous papers in this Magazine (Hawkins, 1910 and 1911) I have dealt with some features in the comparative anatomy of the ambulacral and interambulacral areas of the Holectypoida. The only other structure of the test for a comparative study of which sufficient material is available is the apical system. The present paper deals with this structure. I intend to summarize the results of my researches in a scheme for the classification and evolution of the group in a paper already partly prepared.

It is remarkable that in English geological literature and in our Universities so little attention is given to this important branch of geology. Probably it is because in this country petroleum occurs only in small quantity; nevertheless, in many parts of the British Empire petroleum mining has become a great and increasing industry, and is one of the chief directions in which geology is of practical use to-day. The writer therefore hopes that an orderly summary of present knowledge may be useful.

The distribution of the Rhætic rocks in Warwickshire is not represented on the existing Geological Survey maps because at the time that the survey was made their distinctness from the Lower Lias was not appreciated, and therefore they were represented by the same colour.