A recent paper by Mr. A. R. Horwood on “Aragonite in the y Middle Lias” raises again the question of the condition of the calcium carbonate in fossil shells. Mr. Horwood speaks (p. 176) of Jurassic shells as being “preserved in aragonite”, and quotes Dr. Sorby as being of the same opinion. But is Mr. Horwood sure that his shells are still in the aragonite condition? Sorby, when he writes of “aragonite shells”, means as a rule shells that were formed of aragonite at the time of the death of the originating animal; but he describes how, in many of our fossiliferous rocks, such shells are represented either by hollow spaces or by pseudomorphs in granular caleite. He points out that oolitic grains, originally consisting of aragonite, have similarly been changed into calcite, the more stable form of calcium carbonate. Some oolitic grains, however, were thought by him to have consisted of calcite from the outset. Doelter, after summing up Linck's researches on calcite and aragonite, states that calcareous oolites now consist of calcite; and we have no doubt that the “recrystallized aragonite concretions”, quoted by Mr. Horwood from Sorby, were held by Sorby to be at the time of examination in the calcite state.

In the early numbers of the Geological Magazine the ‘Dragon-tree’ received considerable attention. It was thought to be a Monocotyledon and described as a species of Dracæna by Mackie in 1862 (Geologist, p. 401, pl. xxii). The specimen appears to have attracted an unusual amount of interest prior to 1870, and it is referred to by Mantell and other contemporary writers. Carruthers placed it among the British fossil Pandanaceæ in 1868 (GEOL. MAG., p. 154). Like other specimens from the sandstones of the Iguanodon Quarry (Lower Greensand of Maidstone), no internal structure appeared to be preserved, and the determination of its nature rested entirely on the external features.

As I could not give in this paper anything like a full account of my observations and the results of my studies concerning this question made during an expedition through Iceland in the summer of 1908, I must refer the reader to my special papers on this subject. Everyone will find there the reasons which have induced me first to suppose the independence of the so-called ‘Schild’ volcanoes in Iceland of pre-existing fissures. This idea is confirmed by collecting proof after proof on the subject in the field during my researches. Naturally I could not give all the details in a first short preliminary communication, a fact which, I am sorry to say, has caused Professor Schwarz to doubt the correctness of part of my observations and conclusions. I may therefore be allowed to discuss shortly the two main objections of Professor Schwarz to my theory.

The district under consideration embraces that part of the county of Kincardine which lies south of the Highland fault. Excellent maps on the 1 inch and ¼ inch scale have been issued by H.M. Geological, Survey, but no detailed description of the geology of the area has yet been published. Most of my vacations during the past three years have been spent in studying the geology of this interesting region, and although the work, which has included detailed mapping of the whole area on the 6 inch scale, is not yet complete, several points have been made out, the importance of which has led to the publication of this preliminary note.

The question as to the existence and characters of the jaws in Conulus albogalerus, Leske, has long been a subject of controversy. On prima facie evidence it seemed probable, so long as the genus was retained among the Holectypoida (the Galeritidæ of older authors), that jaws existed. Conulus appears as a successor to Discoidea among the Cretaceous Echinoids, and, with a few exceptions, all echinologists admitted that the latter genus was armed with a lantern and teeth. The truth of this assumption was proved by Lovén (Lovén, 1892, p. 53), and the details of the jaw structure were elaborated recently by myself in this Magazine (pp. 148–52, PL VI, 1909). That Conulus should be classed among the Holectypoida seems to be an established proposition, and it appeared in the early part of the Cretaceous period, together with Pyrina, probably as an offshoot from the Holectypus line of descent.

In the Geological Magazine for December, 1907, a brief account was given by Dr. Henry Woodward, F.R.S., of the work of a small committee of Littleborough and Rochdale geologists, who have for several years been engaged in an examination of the Arthropod Beds at Sparth Bottoms, Rochdale. At Sparth Bottoms several beds of greyish-blue shale, containing clay-ironstone nodules, crop out; the nodules have yielded to the hammer a surprisingly large number of new forms of Arthropoda, some of which have already been figured and described, and others still require further investigation. The beds exposed in the quarry are estimated by the author as 135 to 180 feet above the Royley Mine Coal Seam.

The United States Geological Survey has issued a paper, by Professor R. S. Tarr, of Cornell University, on the Physiography and Glacial Geology of the Yakutat Bay Region of Alaska. Here we have high coastal ranges, culminating in Mounts Cock and Seattle, from which descend great glaciers to the sea, and also other glaciers which come down to the waters of Russell Fiord. The whole region shows signs of intense glaciation during quite recent times, and on this account is an admirable area for the study of glaciers and their work.