Since the date of my communication to the Geological Society on the sections at and in the neighbourhood of Twt Hill, I have more than once visited the district, and have spent much time in working over the specimens which I have collected. The exact relation of these conglomerates to the granitoid rock on which they rest is a matter of great importance as bearing on theoretical questions relating to metamorphic changes in stratified rocks— questions at which for the last three or four years I have lost no opportunity of working. I should therefore, in all probability, have recurred to the subject, even if my attention had not been directed to it by my friend Dr. Roberts' communication and criticism of the above paper. In the latter, it may be remembered that we assigned the Twt Hill conglomerate to the granitoid series.

The country at the base of and forming the south-western slope of the Urals has been little visited by geologists from Western Europe, and deserves more attention than it has received. Several years' residence in it form my excuse for recording a few notes thereon. The area I have travelled over extends from Samara on the Volga in the W. to Preobrajensky and Bieloretzky in the E., and from Orenburg in the S. to the town of Ufa in the N. The formations met with within these limits are the Silurian, Devonian, Carboniferous, Permian, and Jurassic. The three former are the crystalline rocks of the Urals, the western edge or front range being composed of Carboniferous grits and limestones.

It is rather remarkable that the Theory of the Permanence of Continents and Oceans has passed so comparatively unchallenged by geologists. I long since attempted to show that Mr. Wallace's supposition that the Chalk was a shallow and littoral sea deposit was untenable. In comparing analyses of chalk, as he does, with Atlantic ooze, no allowance whatever is made for the loss of iron from the body of the chalk by crystallization, nor for the segregation of silica into flints. The Chalk may have undergone so great a change in addition, since its upheaval vast ages ago, through the removal of some of its constituents by percolating water, that comparative analyses can only be of value when these losses are taken into consideration.

The purpose of this communication is to supplement the author's paper on the “Classification of the European Rocks known as Permian and Trias,” which has appeared in recent numbers of this MAGAZINE. It is based on a short communication made to Section C. of the British Association at the recent meeting at Southampton, and has been expanded into the present paper at the request of the President of the Section, E. Etheridge, Esq., F.R.S.

In the Geological Magazine, November, 1881, I published a brief description, accompanied by a Plate, of a new species of spinose Homalonotus, which I named after its discoverer, H. Champernownei.

On the accompanying Plate IV. Fig. 3, 1 have given an illustration, of the tail probably referable to the above-named species.

On removing the superficial sand and soil to prepare for getting clay for brick-making, it is not unusual to find the surface of the Boulder-clay in this neighbourhood corrugated with tortuous channels. These channels are commonly filled with slutchy sand and gravel, which must be removed before the clay can be obtained.

At the present time there is an excellent example to be seen in Earle Eoad, Smithdown Road, Liverpool, next to the site of a new Board School that I am, as architect, superintending. The surface of the ground slopes rather quickly to the valley below, and the superficial strata consist of soil and a yellow subaërial quartzose sand, together from 4 to 5 feet deep, in which there are no stones or gravel. This sand we are using for mortar, it being what is called “sharp,” or consisting of angular grains. Below this the corrugations of the Boulder-clay are better developed than I have seen elsewhere, and give a clue to the origin of these channel-like depressions.

A correspondent of the “Coblenzer Zeitung,” dating from “Höhr, 27th December,” writes that on the preceding day two meteorites fell near the road leading to the former frontier, in the direction of Ballendar, and that the fall was attended by a very characteristic explosion. The editor of the above journal has been unable to gather any further particulars of the occurrence beyond the fact that the stones fell in a wood, and could not be discovered.

Dr. Divers has drawn attention to two Japanese meteorites, the property of a gentleman, Mr. Naotora Nabeshima, formerly Daimiyo of Ogi or Koshiro, in the province of Hizen, Japan. They are heirlooms in his farnity, and used to be in the care of the priests of one of the family temples in Ogi, called Fukuchi-inGomado. After the revolution the temple was closed. in the family archives there is a record of these stones having been entrusted some years after their fall to a priest named Jishobo, which is dated December 10th, 1744, and his receipt for them is also preserved; they must therefore have fallen about 150 years ago.

Mr. A. G. Nathorst, whose recent contributions to the Palæobotany of Sweden have been very valuable, has been turning his attention to the impressions found on the surface of schists, especially in Palæozoic rocks, which have been too readily accepted as impressions of plants. They find a place among the Algæ of Schimper's “Traité de Paléontologie Végétale,” and they are employed by Saporta and Marion in their recent work, “L'Evolution du Régne Végétal,” and are treated as Algæ, and employed as data in their account of the evolution of the vegetable kingdom. Mr. Nathorst, so long ago as 1873, called in question the plant origin of many of these markings, and he has recently published in the Transactions of the Royal Swedish Academy (vol. xviii. No. 7, Stockholm, 1881) an exhaustive treatise on the subject, with eleven phototypic plates of impressions which he obtained by the motions of different animals or the trails of plants on soft materials.

In a previous communication to this MAGAZINE I suggested that the Loess originated from the thawing and refrigeration, during the major and minor glaciations, of the upper layer of the soil, which, where it was unprotected by land ice, was permanently frozen to a great depth; such layer having a sliding motion which caused the material to accumulate in the hollows, and so expose continually to this action over the rest of the surface, fresh subsoil which had been previously permanently frozen. I now supplement this by a particular examination of the way in which such process appears to me to have acted in originating that part of the Loess which is represented by the ‘Limon,’ or briekearth, of Picardy.

In Two papers, read in 1881, before the meeting of the British Association at York, Prof. Prestwich has discussed the structure and distribution of certain deposits which he has called “The Mundesley and Westleton Beds.”inhis opinion they occupy an horizon “between the Chillesford Beds and the Lower Boulder-clay.”

My work on the Geological Survey in Norfolk has, however, led me to conclusions that differ in important particulars from those of Prof. Prestwich, and chiefly in the correlation of beds in several localities. As his papers have at present been published only in brief abstract, it is not possible to criticize them with justice to the author; but as a year has now elapsed since the conclusions were made known, I may be pardoned for submitting my own views for discussion at the present time.

Brezina points out that in the Catalogue prepared by Tschermak this iron is indicated as of, showing fine-ruled Wiedmanstättian figures. It differs, however, very much from other irons of this group, like that from Lion River, Jewell Hill, Charlotte Co., etc., while it closely resembles the Butler iron. While, however, in the latter case the chief walls of the skeleton inclose very large chambers, here they are very small, so that the skeleton-character is far less marked.

A few words of explanation are required to enable those not familiar with the Carnarvon district fully to appreciate the importance of Prof. Bonney's confirmation of the view respecting the age of the Twt Hill conglomerate first put forward by Prof. Hughes, and afterwards advocated by myself. The controversy possesses a general interest, apart from the fact that the stratigraphical position of a certain bed is now fixed, inasmuch as it shows how cautious it is needful to be in dealing with these ancient rocks without the most thorough and careful mapping of the whole area.

At Penyrhiwan, Clynnog, in the middle of fields, is a protruding boss of dark-coloured rock which has been well broken into, in order apparently to see whether it was available for making “sets” or pitching stones, which form the staple trade of the adjoining district. Its surface is well rounded, as if by glaciation. The boss consists of at least three varieties of rock. Most noticeable is a coarse-grained hornblendic one of handsome appearance, the glistening cleavage planes of the brown hornblende standing out from the remaining green actinolitic portion. a second variety is a fine-grained greenstone, which is separated from the preceding by a hard definite line, so that it may be taken to be of the nature of a dyke intruded into it.

Of the fauna of the Dyas Credner remarks that it is much poorer than that of Carboniferous times, and with the exception of a few reptiles and fishes, limited to the marine formation of the series. of all the lower forms Brachiopoda are by far the most prevalent, and furnish the most characteristic and most widely distributed of Zechstein remains. Lamellibranchiata assume, however, an importance unknown to them in earlier periods, and in their general character tend more towards Mesozoic than Palæozoic forms; he even suggests that Schizodus may be considered the ‘precursor (Vorläufer) of the Trigonia’

Having examined the various theories of the origin of the Loess, which have been current, and found them wanting, I would, with great deference, propose another which has not hitherto been suggested by any geologist, and which offers at least a probable solution of our untractable problem. In previous papers of this series, if we have not proved, as we think we have, that the evidence in favour of the Mammoth and his companions having been suddenly overwhelmed by a great diluvial movement is unanswerable, we claim to have at least shown a very strong á priori probability in favour of such a view.

If we now turn further east to Belgium and its borders, we shall find the same conclusion arrived at by inquirers. In the admirable memoir of M. d'Acy, already named, entitled “Limon des Plateaux du Nord de la France,” the author has examined in great detail and with care the composition of the loamy mantle that overspreads the other surface deposits of Belgium and Picardy. His sections and descriptions show very clearly how its texture, passing from coarse materials in its bottom layers and gradually getting finer and more pulverulent in its upper ones, is such as we should expect from the effect of gravitation acting upon great masses of mud, etc., borne along by a rapid flood.

In the Midland Counties the rocks mapped as Permian are considered on all sides, if Permian at all, to belong to the Lower or Rothliegende series; we need not therefore stop to discuss them at any great length here. The chief authorities are Mr. Howell and the late Prof. Jukes. In Warwickshire the case is a simple one: there is, according to Mr. Howell, a general unconformity of the rocks called Permian with the Triassic strata which lie above them. In the Staffordshire area the case is somewhat different. After a careful perusal of Mr. Jukes's Memoir, I fail to find that his survey of the district enabled him to furnish any direct evidence of the unconformity between the Permians and the Trias, in the existence of which he expresses his belief in the text.

In my former short communication on this subject, I referred only to the question of the age of the quartz conglomerate at Nebo, which Dr. Callaway mistook for a part of the granitoidite series, but which Prof. Hughes has shown to be Cambrian conglomerate. What Dr. Callaway says in reply may be seen at page 287. The second point which I stated I should deal with later, I now take up. Dr. Callaway wrote (GEOL. MAG. 1881, p. 423), as follows :—

As this subject has been a matter for considerable debate during the past few years, and the British Committee of the International Geological Congress have had the matter under their consideration, it may be useful if I attempt to place before the readers of the Geological Magazine the results of the investigations of our sub-committee. As is well known, the term “Poikilitic” has been proposed in some quarters as a comprehensive name for both series, some writers advocating the view that they ought to be regarded as one “system,” as indeed they were of old under the name “New Red Sandstone.”