Of the Swedish Graptolites up to this day but very little seems to be known in foreign countries. They merit, however, more attention than has hitherto been bestowed on them—chiefly perhaps because of the scantiness of the literature. The Graptolitic faunæ of Sweden have many analogies to those of other Silurian districts, and are therefore of great importance for the identification of the strata. An acquaintance with them is also required if one wishes to obtain a somewhat accurate knowledge of the vertical and horizontal range of the various types. A short account of them might therefore possibly have some interest even to an English geologist.

The foregoing paper was sent to me by Dr. Linnarsson, along with a fine collection of Swedish Graptolites; and I am happy to be the medium through which his interesting observations appear before the English public. With singular acumen, the distinguished Swedish geologist has unravelled the intricacies which beset the study of the distribution of the Graptolites in past time; and his results are of peculiar importance and value. Some of these results, in so far as they especially bear upon British Geology, may just be indicated here.

Igneous Action and Metamorphism.—I have already referred to the fact that igneous eruptions were frequent during Palæozoic time. As far as there is any evidence at present, they do not appear to have taken place during the Cambrian Epoch either in Europe or in North America. In Europe contemporaneous tuffs or ashes are found for the first time in the succession in the Arenig rocks; and in America about the same period, or perhaps a little earlier. By referring to the Table, p. 156, it will be seen that the contemporancous traps also occur only in the areas which had undergone most depression, or where the greatest amount of sediment had accumulated. Sir J. Herschel has urged as a reason for this that the crust after a continued period of depression would descend to a point where the heat would be sufficiently great to melt it through, or to weaken it; and that as a consequence fractures would take place, and there would then be a corresponding rising of heat and fiery matter from below, to that of the accumulation of the sediments.

It is now more than eleven years since I ventured to take a part in the discussion then raised by Professor Ramsay having lately published his celebrated theory of the Erosion of Lake-Basins by the lower ends of Glaciers, where they may have formerly expanded over a more level country, beyond the confines of their parent valleys. It appears to be admitted that a great many lakes lie in positions where it would be natural to suppose them so formed, if only glaciers could have possessed the crosive powers necessary for the purpose. The positions of the deeper parts of the lakes also accord well with the theory.

Cretaceous Beds.—During our previous Expeditions we had not fallen in with any strata belonging to this period on Spitzbergen; but in the beginning of the Expedition of 1872 I had the good fortune to supply this missing link in the geology of Spitzbergen through the very unexpected discovery, in the immediate neighbourhood of the Taxodium strata at Cape Staratschin, of fossil plants, which had an unmistakable reference to the fossils which I brought home some years ago from Kome in Greenland (Lower Cretaceous). A closer examination by Professor Heer showed that this supposition was so far correct, inasmuch as the strata in question truly belonged to the Cretaceous series, though occupying a position more recent than the Kome strata in Greenland.

The above form I found a year or two ago in the Encrinital Limestone forming the upper bed of the Lower Limestone Shales which occur on the south side of Combe Down (overlooking Combe House), near its western extremity. I have also traced it in an outcrop of the same limestone in the plantation on the north side of Kings-weston Down, near its western extremity. At both these localities the fossil is associated with Zaphrentis Phillipsi, a small coral which is characteristic of the bed. Palæacis probably also occurs in the corresponding beds exposed in the Avon section, and elsewhere; but though tolerably abundant, is not likely to be observed, on account of its small size, except where the rock is well weathered. The accompanying are sketches of two specimens from Combe Down which much resemble those figured in the Geol. Report of Illinois (Meek and Worthen), vol. ii. p. 262, plate 19, fig. 1 a, b, c.

It may be worth while to record the occurrence of phosphatised carbonate of lime in Cave Ha, near Giggleswick, which has been explored by Prof. Hughes (see Journal of the Anthropological Institute for December, 1873, vol. iii.). The phosphatised material, which forms stalagmitic layers at the side of and interstratified with the other deposits, is leaden-grey in colour, weathering light brown outside, friable, and full of small holes. Portions of it yielded, on analysis, a large per-centage of phosphate of lime.

P.S.—Erratum.—There is an Erratum in my last communication which appeared in the Geological Magazine for April last at p. 149, 20 lines from foot of page, for “older than any metamorphic rocks of Scandinavia,” etc., it should read “older than any non-metamorphic or ‘clastic’ rocks, etc.—G.L.