Zoarium unilaminate, adherent.

Zoœcia fairly large, with very little external front wall; areas widely elliptical, flattened for a short way at the upper end and surrounded by a slender rim, average length ·5 mm., breadth ·35 to ·4 mm.

One of us has been engaged for some years in the study of the Pleistocene gravels and associated deposits of the Cambridge district, and eventually proposes to give a full account of the results obtained. Meanwhile, considering the importance of noting the conditions under which Pleistocene floras are preserved, in order to draw attention to their probable occurrence under similar conditions elsewhere, it is thought advisable to give a preliminary account of the discovery of an Arctic flora of this date in a pit at Barnwell, a suburb of Cambridge, long noted for its Pleistocene deposits.

Early in January, 1916, Dr. O. P. Hay, of Washington, D.C., referred to me for description the fossil bone of a large bird that had been discovered in the eastern part of South Carolina some time previously. This specimen I at once recognized as the lower extremity of the right femur of some bird belonging to a species much larger than any existing form in the United States. I find this specimen to be thoroughly fossilized and of a dull-black colour, the edges of both condyles being considerably chipped off. On the antero-internal aspect the shaft appears to be cut away as if by some shaving implement. This, and where the shaft is broken nearly squarely across above, exposes a filling of a dense, very hard, pale-grey matrix, with a grain as fine as clay. Judging from this there should be no doubt but that this femur was a thoroughly pneumatic one in the living bird, and that the thickness of the osseous wall of the shaft was by no means great, as may be appreciated by examining the figures on the accompanying Plate XV.

This, perhaps the most complex crystalline area of the Piémontese Alps, is also eminently sui generis, for it forms a unit of rocks outside, and different from the great calc-schist horizon with pietre verdi of secondary composition. As previously stated, it is the continuation of the mica-schist and minute gneiss belt which skirts the Po Valley from the Rocciacorba group to Avigliana, Monte Musiné, and Lanzo, and, extending from Lanzo to Ivrea, Biella, and Val Sesia, reaches beyond the latter into Lombardy to Lakes Orta and Maggiore. Within the Piémontese Alps, viz. from Lanzo to Val Sesia, it is bounded on the north by the calc-schist and pietre verdi fringe which skirts the Monte Rosa gneiss massif, and on the south by the Pliocene and Pleistocene deposits of the Po Valley, its superficial area being roughly 90 by 15 kilometres or 1,350 square kilometres, equal to over 500 square miles. The lower hills of the southern margin vary from 600 to 900 metres in altitude, which in the centre of the area increases to 1,000 and at the northern margin to 2,500 metres. In its general direction south-west to north-east, the area is intersected more or less at right angles by the following affluents of the Po: Stura di Lanzo, Malone, Orco, Chiusella – Dora Baltea, Elvo–Cervo, and Sessera–Sesia. The valley floors vary at the lower limit of the crystalline area from 300 to 500, and in their upper parts from 600 to 1,000 metres in altitude.

I have just finished the revision of the Neogene Echinids of Egypt preserved in the collections of the Cairo Geological Museum. Before the publication of this work, which will form the fourth fascicule of the Catalogue of the Fossil Invertebrates of Egypt, it has seemed to me that it might be useful to consider the fauna as a whole, drawing from it some conclusions as to the palæobiology of the Neogene seas of Egypt. I wish further to ascertain if the Echinids of this region can be of some aid as regards the stratigraphical divisions, and in synchronizing these with the divisions already established in the other regions of the Neogene basin of the Mediterranean.

A study of the local stratigraphy, tectonics, petrography, and palæontology leads to some conclusions as to the physiography of the epoch in this district. Even studied as a detached area it may be noticed that the Bunter or pebble deposits are west of the sandstones and marls. From the fact that the eastern limits of the first two are west of the marls, and the second (sandstones) west of the pebbles, and from the evidence of other areas, it appears that this purely local west to east succession is applicable to the whole British area, and it is well known that each member thins from north-west to south-east (as a whole). This is the sequence typical of aqueous deposits, and particularly of delta deposits, and at the same time indicates (in part) the direction from which the sediment came.