Zoœcia large and pentagonal, average length about 8 mm., markedly crater-shaped (i.e. with side walls sloping inwards to a deep-lying areal opening): areas sub-pentagonal as a rule : side walls wide, sloping inwards practically all the way from the zooecial margin, the slope gentle in the lower half, then changing gradually to quite steep at the upper end; the two upper corners are occupied by a pair of stumpy perforated tubercles; just below the summit of the steep inward slope at the upper end of the arc, close to the corners and probably communicating with the external tubercles, are two pores so faint as to be hardly visible in full light.

The question of the age of the Maitai Series is one of the most important which concern New Zealand geology, and one which has aroused the greatest controversy and uncertainty. F. von Hochstetter, before any distinctive fossils had been found in these rocks, considered that the “Maitai Series”, which form the hills bounding on the east and south-east the strip of fossiliferous Trias of the Nelson area, were of Triassic age, and underlay the sandstones with Monotis salinaria. In 1873 F. W. Hutton referred the Maitai to the Jurassic on the supposed occurrence of Inoceramus. A. McKay in 1878, during the survey of the Nelson district, found several fossils, obviously of late Palæozoic age, in the Maitai Limestone of the upper part of the lower Wairoa Gorge opposite a place called Martin's Saw-mill. Sir J. Hector identified these as Spirifera bisulcata, Productus brachythærus, Cyathophyllum, and Cyathocrinus. McKay also surveyed and collected from the Maitai slates and argillites at Wooded Peak, on the Dun Mountain Tramway, some five miles east of Nelson. A large bivalve shell having the prismatic structure and general outline and concentric plication of Inoceramus occurs here. McKay, however, in his report adds that “there are material differences between this shell and the ordinary forms of Inoceramus which may warrant its being considered the type of a new genus”.

Mr. G. W. Bulman, in an essay on “Chalk Flints and the Age of the Earth”, states that Professor Owen regarded the layers of flint in chalk as “the remains of successive crops of sponges which grew again and again according to some periodic law”. Mr. Bulman then observes that the only periods affecting rock-formation are annual, and he suggests that sponge-growth might be rapid during the summer months and that free-swimming reproductive spores might be liberated towards winter, the old sponges then dying off. This implies that the water at the depths in which the sponges lived in our Cretaceous seas was responsive to climatic change, and that the sponges were equally responsive. The suggestion breaks down, however, on another ground, when its author points out that it demands the deposition of 3 or 4 feet of chalk in a year, so that the whole of the English strata above the Albian might have accumulated in about four centuries. Mr. Bulman thereupon remains hesitant and enquiring.

At a time when the resources of every branch of science are being devoted to the furtherance of the War, it is not inappropriate to consider in what way geological research is being turned to account. At first sight it might appear that the work of the stratigraphical geologist, the palaeontologist, or the petrographer might be of domestic and academic interest, but would be unlikely to influence the course of a worldwide war. Such researches have received a respectful toleration in this country, but have been regarded as a luxury, to be abandoned first among luxuries in time of stress. I venture to hope, however, that it will not be so necessary in the future as it has been in the past to expend energy in urging the claims of science. In the foundation of the Imperial Trust for Scientific Research we may recognize that at least one good result has arisen from the calamity of war.

When fish-remains were first discovered in the Ludlow bone-bed and other horizons of the Upper Silurian series, some of the fragments were regarded as toothed jaws by Agassiz, who described them under the names of Plectrodus mirabilis, P. pleiopristis, and Sclerodus pustuliferus. The same fossils were afterwards considered to be of Crustacean origin by M'Coy, but definitely proved to be fish-remains by the microscopical examination of Harley, who pointed out that while they could not be teeth or jaws, they appeared to him to be “the posterior spines of the cephalic plate of some Cephalaspidian fish”. The latter view was adopted by Lankester, who treated the specimens as parts of the cornua of a small Cephalaspidian headshield which he named Eukeraspis pustuliferus.

B. Pre–Cambrian, Rhyolitic Series.—(i) At the south–west end of the Craig–y–Dinas mass we find exposed a rock similar in every respect macroscopically to that which is found at Cil–y–Coed. Unfortunately it cannot be followed far, as the land is completely under drift, the top of Craig–y–Dinas itself being capped by a thick layer of drift.