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—__ I.—On tarce TERRESTRIAL SauRIANS FROM THE Ru@tTI0 Beps or Werpmore HILL, DESCRIBED AS AvatoniId SANFORDI AND Picrovon Herveri. By H. G. Szexey, F.R.S., Professor of Geology in King’s College, London. (PLATE I.) N 1894 Mr. W. A. Sanford described, in the Proceedings of the | Somerset Archeological Society (vol. xl, 1894, p. 284), the geological circumstances of the discovery of a large fossil reptile. - The fossil bones were found by the Rev. Sydenham H. A. Hervey and himself in the Rheetic beds in the parish of Wedmore, in the Vale of Glastonbury; and compared to Megalosaurus in its large size and carnivorous character. The remains were generously presented to the British Museum (Natural History) at South Kensington. I have now to redeem a promise made by Mr. Sanford in his paper that I would name and describe the specimens. The fossils comprise teeth, bones of the hind limb, dorsal and caudal vertebree, and ribs. The discoverer remarks upon the way in which the bones appear to have been broken, crushed out of form, and scattered in the deposit. These results are partly due to transport of the specimens at the time of deposition; and partly, apparently, to movements of the strata associated with the uplifting of the rocks in that part of England. _ Only two teeth were saved ; they indicate two distinct genera. One tooth (p. 2, Fig. 1) is of a generalized Megalosaurian type, and has the summit of the crown greatly worn with use, and rounded. The crown is broad and thick, 12mm. wide and 7mm. in thickness; but towards the base of the crown, the width from front to back increases faster than its thickness. The anterior margin is rounded from side to side, as well as convex from above downward. If any serrations were ever developed, they were in the proximal part, which is worn away. In type the tooth resembles Zanclodon and Euskele- saurus. Those types agree with JJegalosaurus in the limitation of the anterior serrations to the upper margin of the tooth in the lower jaw. Mr. Sanford states that the root of the tooth crumbled, and that portions of the lower jaw were found. Taken by itself the DECADE IV.—VOL. V.—WNO. I. 1 2 Professor H. G. Seeley—Dinosaurs Jrom Rhetic Beds. crown suggests affinity rather with Zanclodon than Megalosaurus. The serrations on the hinder border are at right angles to the margin. I refer this tooth to Avalonia, the fossil being found in Avalon, the district associated with King Arthur and his Knights of the Round Table. Fic. 2.—Tooth of Prerodon Herveyi, Seeley. Rhetic Beds: Wedmore (Vale of Glastonbury). The second tooth (Fig. 2) is also represented by an imperfect crown. It is from the lower jaw, but of a very different type. It is 4 inch long and +3; inch wide at the base. It is sharp-pointed and slender, and the only tooth which at all resembles it in form is one from the collection of the late Rev. P. B. Brodie, found near Warwick, now in the British Museum (Natural History), which I refer to the same genus. ‘This acuminate tooth, manifestly smaller than the tooth of Avalonia, and imperfectly preserved, is flattened externally and rather convex on the inner side, where there are ‘three or four short slight ribs towards the lower half of the crown, which some- what recall the ribs in the teeth of Suchosaurus, which the type resembles in form ; but the crown differs from that genus in being more pointed, and especially in having the anterior and posterior margins serrated. The anterior serrations are limited to the summit of the crown. Their general direction is at right angles to the curved surface, but they have a perceptibly greater upward tendency. The posterior serrations are also directed upward. ‘This constitutes a distinct resemblance to Thecodontosaurus and a difference from Megalosaurus, in which the serrations are at right angles to the cutting margins of the tooth, as they are in the short crown of Palgosaurus. ‘The nearest approximation to this kind of serration is made perhaps by the French genus Dimodosaurus. But the serrations, except for their direction, are similar to those of Megalo- saurus, and there is no median ridge running down the length of the tooth such as is figured by M. Gaudry. The tooth indicates the genus Picrodon. I have therefore no doubt that the remains of the skeleton preserved belong to two distinct though closely allied animals, of which the second was the smaller. The true nature of the larger animal, Avalonia Sanfordi, is indicated by the remains of the femur and other parts of the hind limb. The Professor H. G. Seeley—Dinosaurs from Rhetic Beds, 3 femur (PI. I, Fig. 1) is about 38 inches long. It is a moderately strong bone, compressed from front to back, with the proximal and distal ends in the same plane. ‘There is no trace of a sigmoid curve such as is seen in Palgosaurus, and to some extent in Megalosaurus and Dimodosaurus. The least transverse width of the proximal end is 94 inches and the greatest width 104 inches. Of this width, at least 24 inches is due to the inward direction of the convex articular surface, which measures 6 inches from front to back in the middle of the articulation, is flattened above, and is round from above downward as it extends inward. Below the proximal articulation towards the outer border, the front of the bone is impressed for a width of about 3 inches. This condition somewhat approximates to that seen in the corresponding part of the femur of Huskelesaurus Browni; only in that type the transverse expansion of the head of the bone is much less, and the shaft of the bone is nearly cylindrical, shorter, and relatively stouter. The lower border of this impression is an oblique ridge, which passes downward and outward, but is not appreciably elevated; it is 4 or 5 inches long, and is the only representative of the proximal trochanter of Megalosaurus, which is scarcely developed in Huskelesaurus and Palgosaurus, is almost lost in Massospondylus and Dimodosaurus, and passes away in some Zan- clodonts. This is one of the most distinctive characters of the bone. Below the termination of the ridge the external lateral contour of the bone is concave in length, and this causes the shaft to narrow from a width of 7 inches to 5} inches in its middle length, below which it widens again to 114 inches towards the distal end. The middle length of the inner lateral border is occupied by a trochanter, which is now broken away but had the backward direction seen in carnivorous genera of Saurischia. Its broken base is a foot long, is perfectly straight, and occupies the middle third of the length of the bone. Above the trochanter the concave inner border is approximately parallel to the convex external border. The widening of the distal end of the bone is similarly due to an inward extension of the bone below the trochanter in a concave contour. This inner side is flattened and inclines slightly forward, being supported by the large inner distal condyle. The length and position of the lateral trochanter are distinctive; in Huskelesaurus it occupies the middle of the bone, and in Massospondylus it is towards the middle, but in both the African genera it is relatively shorter, while in Palgosaurus and Megalosaurus the proximal position of the trochanter is as pronounced as in Zanclodon; so that this also is a distinctive feature of the bone. The distal end is about 114 inches wide. In front there is a slight concave longitudinal channel, slightly external to the middle width. The distal extremity is truncated. The larger inner condyle seen behind is 7 inches from front to back, and separated from the outer condyle by a moderately deep concave channel about 2 inches wide. The back-to-front measurement between the two channels exceeds 4 inches. The outer posterior surface external to the lesser condyle is oblique, and has the usual compressed aspect. 4 Professor H. G. Seeley—Dinosaurs from Rhetie Beds. The bone is manifestly that of a new Zanclodont Saurian, and the pelvis and other parts of the skeleton may be expected to conform to the types at Stuttgart and Tiibingen. The shaft of the femur is much straighter than in Megalosaurus, and the other characters all tend to remove the genus Avalonia from the types in which the pubic bones are slender and rod-like, and refer it to types in which those bones are flattened plates. Only 16 inches of the proximal end of the left tibia is preserved. The proximal end is greatly expanded, especially towards the anterior crest of the bone. The proximal surface is truncated in the usual way, and is triangular. It measures 12 inches from front to back, and 9 inches from side to side behind, indicating, as the femur is nearly a foot wide, that the fibula had the usual slender form. The inner side of the bone is smooth and convex from front to back; the fibular side has a shallow channel for the fibula. The posterior side is concave in the middle width at the proximal end. These characters are too few to greatly elucidate the characters of the animal, but they are in harmony with the proximal end of the tibia in the genera which have resemblances to the femoral bone. The hind foot is evidenced by digital and terminal claw phalanges. In all characters these bones are so remarkably like those which I have figured in Huskelesaurus (Annals Nat. Hist., ser. vi, vol. xiv, p. 332, 1894) that I can point to no differences between them. The transverse width of the claw phalange removes the animal from all allies of Megalosaurus. It is not quite so wide as the same bone in Cetiosaurus, and conforms to the type of Zanclodon preserved at Tiibingen. The digital phalanges are 252; inches long, as wide behind, narrower in front; 15% inch deep behind, depressed in front. The bone narrows superiorly, and has the trochlear ex- tremities completely ossified. The claw phalange exceeds 4 inches in length, being more than one-tenth of the length of the femur, and _ nearly twice the length of a penultimate phalange. Its articular end is trapezoidal, fully 2 inches deep, and as wide below the middle. The usual vascular grooves extend in arched curves along the sides of the bone, and are continued transversely beneath the articular end. The limb bones probably indicate an animal less than six feet high. The vertebre preserved appear to indicate two animals. The dorsal vertebre all agree in the anterior face being flattened and relatively small, while the posterior face is concave and much larger. In this they resemble the vertebre of Avalonia. But since one type has the centrum 5 to 5} inches long, with the anterior face 6 inches deep, while the posterior face is 8 inches deep, I conclude that it indicates a distinct animal from the second type, in which the centrum is 53 to 6 inches long, with the articular faces vertically ovate instead of circular, 44 inches deep in front, and 5 inches deep behind. After making all allowances for the effects of compression and distortion, J am compelled to refer the larger vertebra to the animal with the larger tooth, and suppose that the animal with the smaller tooth was represented by the smaller dorsal vertebra. The large size of the centrum exceeds Professor H. G. Seeley—Dinosaurs from Rhetice Beds. 5 anything seen in British carnivorous saurians, and is especially large as compared with the dorsal vertebra of Megalosaurus, in which the vertebre are as unlike the fossil as are the limb-bones. The large dorsal vertebra of Avalonia Sanfordi is somewhat crushed, and has the body of the centrum unusually constricted, both at the sides and the base. Above the middle of the side, and a little behind the middle length, is a concave impression, pinching the sides till they are about 3 inches apart. The flattened anterior face is not well preserved, and the margin of the deeply concave posterior face is rounded. The measurements indicate a moderate arching of the back. The neural canal is 25%; inches high in front and 2 inches wide ; behind it is wider than high. The neural arch has a strong elevated capitular facet 2 inches deep and 14 inch wide, vertical and flat, with the anterior border straight and the posterior border convex. It is an elevation upon and ex- pansion of the anterior buttress of the arch, just as the tubercular facet (which is lost with the transverse process) is supported by the posterior buttress, which is a narrow oblique ridge. Hence there is a concavity between the facet and the ridge, which extends under the transverse process. The large posterior zygapophyses extend back beyond the neural spine ; and the buttresses below them, which face obliquely outward and backward, are excavated for the reception of the pre-zygapophyses. The neural spine is compressed and vertical, about 38 inches from back to front and half an inch thick, though there is no certain indication of its height. The transverse width over the neural arch as indicated was ten inches. The height of the vertebree up to the summit of the neural spine may have been 20 inches. The transverse elevation of the capitular facet an inch above the base of the neural arch is a remarkable and distinctive character. The large size of the vertebra is somewhat Cetiosaurian. The ribs were strong: one fragment, more than 15 inches long, is 3 inches deep at the fracture towards the proximal end, where the external surface is reflected somewhat backward, and as the rib extends outward its plane becomes twisted, so as to present a wider and oblique lateral superior surface, the measurement being about 15 inch at the fracture at the distal end. The remainder of the vertebree are referred to Picrodon Herveyi. They comprise dorsal vertebra, with the body of the vertebree com- pressed from side to side, and relatively more elongated, but with the front of the centrum narrower than the back. There is a distinct suture between the neural arch and the centrum. And the neural arch has strong upwardly converging buttresses, supporting the transverse processes. The articular faces are deeper than wide; the width does not exceed 44 inches. A caudal vertebra, showing the base of the transverse process, has the centrum about 5 inches long, and the base of the transverse process 24 inches from front to back, by 14 inch deep. The articular face is about 5 inches deep, by less than 4 inches wide, but the preservation does not show whether chevron bones were developed at the hinder border. A later caudal, with the articular surface 6 Professor O. C. Marsh—European Dinosaurs. fully 24 inches deep and the centrum 4 inches long, has no transverse process, and shows no indication of a chevron facet, though the base of the articulation is somewhat thickened behind. A still later vertebra has the centrum 3 inches long, and the articular face 14 inch deep by 1;4;inch wide. The caudal vertebrae continue to diminish in length, and the neural arch becomes compressed from side to side, but remains well developed, and nearly an inch longer than the centrum. The pre-zygapophyses look obliquely upward and forward, and receive the wedge of the posterior zygapophyses between them. There appear to be faint indications of very small chevron bones in these latest vertebree. It is possible that the smaller caudal vertebra belong to Avalonia. These vertebral characters indicate an animal closely allied to Avalonia, but well distinguished by the lateral compression of the centrum, supported by the singular form of the tooth crown, obliquely serrated at the margin, and ribbed on the inner side. EXPLANATION OF PLATE I. Avalonia Sanfordi, Seeley. Fic. 1.—Anterior aspect of left femur. a, articular head ; 2, ridge representing the trochanter major ; ¢c, broken base of the inner lateral trochanter; d, inner of the larger distal condyle. Fic. 2.—Posterior aspect of a dorsal vertebra. Fie. 3.—Right side of a dorsal vertebra, showing (/) the capitular and (¢) tubercular facets, and the xygapophyses. Fie. 4.—Side view of claw phalange and penultimate phalange of hind foot. Fie. 5.—Articular end of claw phalange. Picrodon Herveyi, Seeley. Fie. 6.—Dorsal vertebra, posterior aspect. Fie. 7.—Same vertebra, lateral aspect. Fic. 8.—Early caudal vertebra, lateral aspect. Fic. 9.—Late caudal vertebra. Rhetic Beds: Wedmore Hill (Vale of Glastonbury), Somerset. See also note on some Rhetic Foraminifera from Wedmore, by F. Chapman, 1895, Ann. and Mag. Nat. Hist., vol. xvi, p. 306. I].—Recent OBSERVATIONS ON LHuropkan DINOSAURS. By Professor 0. C. Marsu, M.A., Ph.D., LL.D., F.G.S.; of Yale College, New Haven, U.S.A. URING the past summer, it was my privilege to attend the International Congress of Geologists at St. Petersburg, as an official delegate from the United States, and this gave me an opportunity to see a number of museums and collections in Europe which I had not before visited. I thus had the privilege of inspecting personally many interesting reptilian remains that I had not previously known, and of examining others which were more or less familiar to me from figures and descriptions. In the present paper, I have only time to speak of the Dinosaurs, in which I have long taken a special interest, and have endeavoured to study all the known specimens of importance, both in this country and in Europe, having in view the preparation of a series Professor O. O. Marsh—European Dinosaurs. 7 of memoirs on the different groups of this subclass of extinct Reptilia. London.—I began my investigations in the British Museum in London, a great treasure-house for fossil reptiles, to which I have long made frequent pilgrimages. This time the Dinosaurs were seen to better advantage than ever before, but of new or unknown forms I found that few had been added to the collection since my visit two years ago; and I consoled myself with the other extinct Reptilia, and especially with the new fossil birds and mammals from South America. St. Petersburg.—In St. Petersburg I hoped to find many Dino- saurian remains, as here had been brought together an abundance of fossil treasures from various parts of the Russian Empire, which I knew must contain many forms of this group. In the four principal museums of the city, however, I could find no bones of Dinosaurs on exhibition, nor could I learn from any of the museum authorities that such remains had been recognized among the specimens received, neither could I find any such fossils myself among the débris of the collections, so often a rich repository for new or inconspicuous specimens. This was true also of the smaller collections visited, and I was at last forced to admit that here, at least, the Dinosaurs of Russia, like the snakes of Ireland, were conspicuous only by their absence. Moscow.—This opinion was not changed by a visit to the rich geological collections of Moscow, which I examined with care ; although other fossil vertebrates, including many reptiles, were abundantly represented. I was assured, moreover, by various Russian paleontologists, that in other museums of the empire or in the known localities they had seen no Dinosaurian remains. This vain quest, however, only proves that the discoveries are yet to be made, and I confidently expect them at no distant day, since in almost every other part of the world Dinosauria have already been brought to light. In Northern Europe west of Russia, and in North America to the east, these reptiles were especially abundant, and the vast territory intervening must contain numerous Dinosaurs, including many new forms of the group. Vienna.—In Vienna I knew that my friend Professor Suess had a large collection of Dinosaurs in his museum to show me, and I spent several days there in their investigation. This collection was of special interest to me, as it was from the Gosau fresh- water deposits, which, as a student, years ago, I explored mainly in the expectation of finding Cretaceous mammals; and I was not without hope of still detecting such remains during my present visit, as here were the localities where they were, in my judgment, most likely to be found in Europe. The Dinosaurs I examined were from Neue Welt in this formation, and were of great interest. They had all been studied by Bunzel, Seeley, and others, who had recog- nized ten or twelve distinct genera and many species among them. I could find, however, not more than a quarter of this number, and among these I found no indications of the Ceratopsia, which from 8 Professor O. C. Marsh—European Dinosaurs. the published figures and descriptions I supposed to be represented in this collection. The Dinosaurs with dermal armour which I saw all pertained to the Stegosauria, and two distinct genera among them were more nearly like Scelidosaurus of the English Jura and Nodo- saurus of the American Cretaceous than any others with which J am familiar. This collection contained the only Dinosaurian remains I could find in Vienna. Munich.—I next went to Munich, which, under Professor von Zittel, has become a great centre for paleontology. I found that the gem of the collection is still the unique Compsognathus, which in several previous visits I had studied with care. A re-examination impressed me even more with the fact, that this is one of the most perfect and interesting vertebrate fossils yet discovered, and no other example of the genus is known. It was in this unique specimen that years before I had detected the embryo, and this fossil still affords the only known evidence that Dinosaurs were viviparous. I could find no other Dinosaurian bones of interest in the Munich collection, the new features being mainly numerous fine specimens of Mosasauria from America, and some interesting remains of Hesperornis and Baptornis from the same horizon in Kansas. I was much pleased to see here the new Jurassic fossils collected by Nansen in 1896, at Cape Flora, in Franz Josef Land. These interesting remains are now under investigation by Dr. J. F. Pompeckj, assistant in the Munich Museum. I could detect no vertebrate fossils among them, although various indications favour their presence in this fauna. Paris.—My limited sojourn in Paris gave me no opportunity for a careful examination of the museums there, but I could learn of no recent additions of Dinosaurian remains since my last visit. Caen.—I next went to Caen, in Normandy, to see the famous Dinosaur Poikilopleuron, so well described by Deslongchamps many years ago. Through the kindness of my friend Professor A. Bigot, I had a good opportunity to study this unique specimen, which of late has been regarded as identical with the Megalosaurus of Buck- land, the first genus of Dinosaurs described, and one about which little is yet known. ; Among the undetermined material of this museum, I was greatly pleased to find the genus Pleuroceelus well represented by character- istic fossils, and from a well-defined Jurassic horizon in the vicinity of Havre. The species appears to be a new one, somewhat smaller than Pleurocelus suffosus from the Kimmeridge of Swindon, England. It resembled still more closely Plewrocelus nanus, which I have described from the Potomac formation of Maryland. Pleurocelus is one of the most characteristic genera of the Sauro- podous Dinosauria, and its value in marking a geological horizon should therefore have considerable weight. It is now known from the two European localities mentioned above, both in strata of undoubted Jurassic age. The same genus is well represented in 1 Lydekker records a Wealden species, Pleurocelus valdensis, in Quart. Journ. Geol. Soc., 1890, vol. xlvi, p. 182, pl. ix. G. F. Harris—Journey through Russia. 9 the Potomac deposits of Maryland, and has been found also in the Atlantosaurus beds of Wyoming, thus offering, with the associated fossils, strong testimony that the American and European localities are in the same general horizon of the Upper Jurassic. Havre.—The last day at my disposal before sailing for America, I spent in Havre, in the Muséum d’Histoire Naturelle, where the director, M. Lennier, showed me many vertebrate fossils of interest, from the well-known localities near the city. Here, again, among the fragmentary specimens not yet investigated, I found the bones of another Dinosaur, also one of the Sauropoda, but considerably larger than the Pleurocelus at Caen. The remains were very similar to those of Morosaurus, and the horizon was, in the Kimmeridge, which is here well defined. From Havre, I crossed the Channel to Southampton, and with a parting look at the Wealden cliffs of the Isle of Wight, which have furnished the remains of so many interesting Dinosaurs, I sailed for home. TIJ.—NaARRATIVE OF A GEOLOGICAL JOURNEY THROUGH RUSSIA. 1. FInnanp. By Gxo. F. Harris, F.G.8., M.S8.G.F., etc. ‘| ie meeting of the International Geological Congress at St. Petersburg towards the end of August last year was about as successful in promoting the main objects the Congress has in view as any of its predecessors. ‘There was a marked absence of any- thing like a serious radical programme, and in that sense the meeting may be said to have been progressive. The majority of the papers read were commonplace, the few exceptions being mostly in the domain of petrology. Hvery geologist who attended the meeting was grateful to the Organizing Committee for getting together such a nice little exhibition of specimens, maps, and models for the occasion. It was full of interest. The official Russian geologists did everything in their power to assist their visitors. They caused certain scientific institutions in St. Petersburg to remain open longer than usual, and were never tired of explaining the rich collections stored in the geological and mineralogical museums in the Imperial University, and in kindred museums. During the week of meeting they organized a day’s excursion to the Czar’s palace at Peterhof, and another to the renowned falls of Imatra—a long distance off, in Finland, but distance counts as nothing in the Russian Empire. Then there were the inevitable receptions, though, fortunately, these were not carried out to the same extent as at the Washington Meeting. But it was not of the actual Congress meetings, nor of the papers read or mumbled before them, nor of the wonderfully preserved. mammalian remains in the temporary museum, nor of the unvarying courtesy of the Russian officials, that I desire to write in these articles. Neither may I say anything in the GuotocicaL Macazine concerning the social aspects of our visit to the other side of Hurope 10 G. F. Harris—Journey through Russia. —of the many banquets held in our honour, of the terrible number of speeches, mostly by self-elected “representative” spokesmen, which frequently commenced shortly after the soup was placed upon the table (so keen was the competition to do justice to our hosts!) : these and many minor incidents, some of a distinctly sensational character, would more fittingly be recorded in the pages of a three- volume novel. The Committee of Organization had arranged that four excursions should take place in connection with the Congress meeting. Of these, three were to be held before the meeting, viz.:—(1) to the Urals, (2) to Hsthonia, (3) to Finland; and one after, namely (4) to South Russia, by the Volga or alternative routes, over the Caucasus through Tiflis to Baku (variations), thence to Batoum and across the Black Sea, through part of the Crimea to Sebastopol, and on to Odessa. I had the good fortune to be included amongst the participants of journeys 38 and 4—to Finland and Transcaucasia; and the aim of these articles is to give some account of the geology along the lines of route pursued by those two parties. To begin with the Finland journey ; and I prefer to write in narrative style. Starting from St. Petersburg at night-time for Helsingfors, we had no opportunity, then, of learning the character of the scenery through which we passed. The next morning broke dull and grey, and through the rain we could see that although the country was flat it was extremely well wooded, and that the fields adjacent to the railway track were strewn with enormous boulders. The country was saturated with water, and the bracken fern and undergrowth generally were doing their best to hand plenty of peat down to posterity. Here and there was evidence of disastrous forest fires, whilst numerous blackened stumps stood out of the peaty soil and could be counted by hundreds in the clearings. Vegetation was not only abundant, but luxuriant, and this in what is usually called cold, icy Finland! And so we continued to Helsingfors, meeting with but little else by the way except an occasional outcrop of granite. At Helsingfors, Wilhelm Ramsay, of the University of that city, met us. ‘This indefatigable geologist has done much for the geology of the country adopted by his ancestors. His work in the Isle of Hogland! and on the Quaternary deposits of Finland? may be cited as examples, whilst he has written joint memoirs with H. Berghell ® and E. T. Nyholm* on the petrography and stratigraphy of the older rocks of Finland. Helsingfors stands at the extremity of a small promontory, which is composed of a heterogeneous mass of what, for want of a better 1 “Om Hoglands geologiska byggnad’’: Geol. Foren. Férh. Stockholm, Bd. xii, 1890. ‘‘ Beskrifning till kartbladen, No. 19 och 20, Hogland och Tytarsaari’’ : Finl. Geol. Und. 1891. ; * “Ueber den Salpausselka im éstlichen Finnland,’’ Fennia 4, No. 2; Helsing- ors, 1891. 3 “Das Gestein von Jiwaara in Finnland’’: Geol. Foren. Foérh. Stockholm, Bd. xiii, 1891, p. 300. * « Cancrinitsyenit und einige verwandte Gesteine aus Kuolajarvi’’: Bull. Comm. Géol. de la Finlande, No. 1, 1895. G. F. Harris—Journey through Russia. Il name, is called gneiss or “granitic schist,” and the same class of rock extends for many a square mile around, relieved only by considerable extensions of overlying Glacial and Post-Glacial clays, and sands. The gneiss is believed to be of Archean age. It is an indescribable mixture, the so-called foliations resembling flow- structure, leading one. to the belief that the whole was due to contact metamorphism. In certain cases, where schistose fragments appear to have been more or less absorbed, such an explanation is highly probable ; but, except the “ Rapakivi,” practically all the granite of South Finland, for at least 200 square miles, is foliated or ‘‘oneissose,” or ‘schistose.” Over large tracts appearances are certainly in favour of differential movements in the magma. But I will not say much about the rock, for our opportunities of examining it in the field were very small. The islets which add so much to the beauty of the environs of the Finnish capital are constituted either of this gneiss or the “ gneissose granite.” The courteous Director of the Geological Commission of Finland, Mr. J. J. Sederholm, invited us all to the offices of the Survey, where he had prepared a representative collection of rocks and minerals, and examples of such fossils (all Quaternary) as have been found in the country. Sederholm’s contributions to geology are already important. Amongst other things he has prepared a small geological map of Finland in two editions—solid and drift. He has especially studied the “Rapakivi”! and Archean? rocks of South Finland. During the past year or two he has been engaged on the detailed mapping of the extremely interesting country in the neighbourhood of Tammerfors.* In conjunction with W. Ramsay, he prepared the useful guide* for the use of members attending the Finland excursion. The collection of specimens at the office of the Geological Com- mission proved very interesting, and, in a measure, served as an illustrated guide to the class of rocks which we were to study in the field during the following week. Many types, however, did not lie along our track; amongst these latter were marvellous examples of “yapakivi” and some “globular” granites, and a word or two respecting them may not be out of place. The peculiar kind of “granite” known as rapakivi has, typically, a number of large phenocrysts, commonly rounded or ovoid, com- posed of a kernel of orthoclase enclosed within an envelope of oligoclase (Fig. 1). The rock between these phenocrysts is fine- grained and frequently micropegmatitic. The formation of the acid ' << Ueber die finnlandischen Rapakiwigesteine’’: Tscherm. Min. und Petrogr. Mitth. Wien, Bd. xii, 1891. 2 « Archaische Eruptivgesteine a. d. stidwestlichen Finnland’’: id., Bd. xii, 1891. ‘Ueber einen metamorph. pracamb. Quarzporphyr von Karvia, Proving Abo’’: Bull. Comm. Géol. Finlande, No. 2, 1896; ete. 3 “ Archiiische Sedimentformation im siidwest. Finnland’’: Bull. Comm. Géol. Finlande, No. 6, 1897. 4 «Guide des excursions VII Congrés Géol. Internat. : XIII, Les Excursions en Finlande’’; St. Pétersbourg, 1897. 12 G. F. Harris—Journey through Russia. before the more basic felspar in the phenocrysts, and the detailed structure accompanying that phenomenon, form a very instructive study. At the same time, the term rapakivi is largely applied by the geologists of Finland to holocrystalline rocks of granitic type Fie. 1,—‘‘ Rapakivi granite ’’ (4 nat. size). a=orthoclase; 6=plagioclase. which contain large, rounded, and even. irregularly - shaped phenocrysts of orthoclase, and which may not have the triclinic felspar wrapping round them, except in very rare instances in any one massif. It is used, in fact, as a general field term for granites of that description of Pre-Cambrian age. As thus defined, ‘“rapakivi granite” extends over enormous areas in Southern Finland, on the north-eastern shore of Lake Ladoga, in the little island of Hogland in the Gulf of Finland, and in the Aland archipelago. It is one of the youngest of the Pre-Cambrian eruptives in the country, and has been classified by Sederholm* in his Jotnian formation—the younger subdivision of the Algonkian (or Archzeozoic) group. The “ globular granites” exhibited at the offices of the Geological Commission (some of which were subsequently shown in the temporary museum formed in connection with the Congress meeting at St. Petersburg) have been described in some detail by Benjamin Frosterus.2. The accompanying diagram (Fig. 2) represents one of these rounded or ovoid bodies. Mr. Frosterus tells me that the kernel is frequently formed of a fragment of biotite schist. Following his observations in the work just quoted, it will be seen that, normally, there is a kernel or nucleus, outside of which are four successive zones. In the diagram (Fig. 2) a represents the nucleus, which, in the specimen analyzed by Frosterus, contained 63-64 per cent. plagioclase (Ab, An,) with 18-92 of biotite and 19°60 of quartz. Then followed the first coating or andesine zone (b), in which the plagioclase (Ab, An,) amounted to 73°22, biotite 8:00, and quartz 1650. The next coating, the oligoclase-andesine zone (c), yielded plagioclase (Ab, An,) 56-07, biotite 5:60, and quartz 89°72. This is succeeded by a microcline zone (d), in which we have plagioclase (Ab, An,) 16°52, alkali-felspar 57-44, and 1 “¢Guide des Excursions,”’ etc. (op. cit.), p. 18. 2 “ Kugelgranit von Kangasniemi in Finland’’?: Bull. Comm. Géol. Finlande, No. 4, 1896. G. F. Harris—Journey through Russia. 13 quartz 26°74. The outermost zone (e) has plagioclase (Ab, An,) 44:28, alkali-felspar 6:79, biotite 4:00, quartz 42°82. The mineral composition of the stone between the globular bodies is plagioclase (Ab, An,) 385-49, alkali-felspar 16°88, biotite 12:27, quartz 32°53. From this and from the chemical composition of the different zones and the “ muttergestein,” it is evident that the general tendency of the ordinary separation of the crystals from the original magma was normal—that the zones, on the whole, become more acid as they recede from the nucleus. The proportion of Si O,, for example, in zone 6 is 61:64, ¢ 72-92, d 74-80, and e 75°67, whilst the rock between the globular bodies has 70:46. Not the least interesting feature in these remarkable bodies is the mechanical deformation to which they have occasionally been subjected, and which has had the effect of breaking through the zones and squeezing out some of the substance of the interior. In certain of these Finnish “globular granites” shown at Helsingfors the spheroidal and ovoid bodies have been partially absorbed by the matrix in which they occur. The concentric zoning is clearly marked, and in most cases the minute crystals are so arranged as to produce a radiating effect. Fig. 2.—‘‘ Globular granite.’’ Diagram showing disposition of zones _ in one of the typical ovoid bodies (about } nat. size). The dis- tinguishing italics are explained in the text. The structure of these bodies differs somewhat from that of the well-known spheroids in the granite of Mullaghderg, County Donegal, described by Dr. Hatch,! though the Finnish rock agrees better with the Irish than with certain Continental rocks adverted to by the last-mentioned author. At length, after a stay of three days, it was time to leave Helsingfors, and Mr. Sederholm took charge of the party. A long railway ride north, to Tammerfors, and an enthusiastic welcome from 1 Quart. Journ. Geol. Soc., vol. xliv, 1888, p. 548 et sqq. 14 G. F. Harris—Journey through Russia. the inhabitants of that manufacturing town were the first items on the programme. The country seen on the way was flat or but slightly undulating, with low hills occasionally ; the whole well wooded and watered. The Glacial clays passed through shortly after starting were here and there covered by Post-Glacial clays and littoral deposits containing Litorina, Cardium, Mytilus, Tellina, ete. A ridge of considerable size was traversed by the railway at Hyvinkaa, which proves to be a large terminal moraine. To the north of that place moraine gravels predominate, and there are several asar, a phenomenon which I intend to describe more particularly at another stage of our journey. Then several lakes come into view, and Tammerfors with its hilly scenery is reached. Tammerfors is situated on a narrow neck of land formed by an “as,” which separates the lakes of Nisijirvi and Pyhajarvi. The former lake is about 58 feet above the latter, and the two are con- nected by rapids, which in parts are very beautiful. The journeys for the next two or three days were from that place as a centre, a special train being always at our disposal. The neighbourhood of Tammerfors is excellent for studying the Archean rocks of Finland. The following divisions are recognized by Mr. Sederholm ? :— 1. Post-Bothnian granite. 2. Bothnian schists. 3. Pre-Bothnian gneiss. In the last division, granites (essentially metamorphic), porphy- roides, and closely foliated gneiss predominate. These latter, according to Sederholm, are granitized mica-schists. All these rocks crop out to the south of the town. We examined the foliated granite and mica-schist (on the after- noon of our arrival) in a railway cutting at Siuro, about twenty miles west of Tammerfors; and in a railway cutting to the west of Suoniemi we had an opportunity of examining the mica-schist highly plicated. The micro-structure of these and some other Finnish rocks will presently be described. We will turn now to the second division—the Bothnian schists, which, as will be seen as this narrative proceeds, we examined at many points. The local development of these is known as the Tammerfors schists. They crop out in bands running east and west, the whole being highly inclined and limited by tie Pre-Bothnian gneiss on the one hand and the enormous outcrops of the Post-Bothnian granite on the other. These schists are often represented by phyllades,? which occasionally approach true argillites and sometimes pass gradually into fine-grained mica-schists. The foliated arkose, which Mr. Sederholm calls “leptite” (to be more particularly referred to hereafter), occurs in this subdivision. So also do certain hornblende (mostly uralite) schists (called porphyritoides), which were originally volcanic tuffs, and sometimes have altered lavas inter- calated between them. 1 « Excursions en Finlande’’ (op. cit. supra), p. 2. 2 This term is here used in its broad sense. Professor T. G. Bonney—Lake-basins in the Alps. 15 - But one of the most remarkable features of the ‘“ Bothnian schists” in the neighbourhood of Tammerfors is the presence of conglomerates on several horizons. ‘These, in many instances, are so fresh that one finds some difficulty at first in believing that they are really Archean. The waves of Lake Nasijirvi, in the lovely bay of Hormistonlahti, where these conglomerates are well exposed, have assisted the atmosphere in picking out the more or less crystalline cement between the pebbles. In other situations these Finnish rocks reminded me strongly of certain Cambrian conglomerates in North Wales; but I do not desire to draw the comparison any closer, for the Cambrian of the neighbouring parts of Russia, as everyone knows, is peculiar. as being so little affected by the ravages of time. Mr. Sederholm places’ the thickness of the Tammerfors schists at from 4,000 to 5,000 métres—2,000 métres for the phyllades, 1,500 for the lower tuffs and conglomerates, and the remainder for the upper tuffs with their intercalations of phyllade and con- glomerate. The Post-Bothnian granite, which crops out to the north of the schists in the Tammerfors area, is shown by Sederholm to traverse the latter, veins being thrown out at certain places, and large pieces of the schists being caught up at frequent points along the junction between the two rocks. And these pieces of included rock, in addition to possessing the structure and mineral composition of the Tammerfors schists, have occasionally been discovered to contain typical pebbles as found in the last-mentioned formation. As I proceed with the narrative, I propose to give field notes and some account of the micro-structure of examples of these Archean rocks which I collected, and to deal with the Glacial deposits, in the next article. (To be continued.) TV.—NOoTES ON SOME SMALL LAKE-BASINS IN THE LEPONTINE ALPS. By Prof. T. G. Boynzy, D.Se., LL.D., F.R.S., V.P.G.S. OCK-BASINS have been getting out of favour of late. The “heckling”? which they have suffered from my friend Mr. Marr tempts one to echo Betsy Prig’s classic remark about Mrs. Harris. Mr. Brend, however, though “dealing faithfully ” with them in the September number of the Gronocican Magazine, does permit one or two to exist on sufferance, so that I feel minded, were it only as an act of charity to these depreciated securities, to describe two or three examples in the Alps which I think must be true rock-basins. The first is called the Lago Tremorgio.? It lies, at a height of 5,997 feet above the sea, on the southern flank of the Val Bedretto, at the top of a long and steep ascent from Fiesso. It is slightly irregular in outline, but circular in form, with a diameter between 1 Op. cit. supra, p. 4. 2 I examined it in 1893. 16 Professor T. G. Bonney—Lake-basins im the Alps. seven and eight hundred yards. It is almost enclosed by steep slopes and crags, and is entered through a narrow V-shaped gully, with a rapidly rising ridge on either side. Through this gully runs the stream which carries off the water of the lake. I followed a track which mounts gradually up the right bank, and no blocked outlet exists on that side; I had an excellent view of the other bank, and feel certain there could not be one there. In fact, the rapid rise of the rocky ridge on either side and its outline are almost conclusive to an eye accustomed to mountain forms against there South. M4 ty ( ( I nad North. Fre. 1.—Broken horizontal lines: Gneiss. Vertical lines: Schists, micaceous, etc. White: Water. (Scale as below, Fig. 2, on p. 17.) being any outlet to the cirque but the present one. At this the live rock can be seen not only on either side but also in the bed of the stream. Of that I could be sure, because the channel had been deepened, apparently in order to add slightly to the pasture-land by lowering the level of the lake, and had been cut down for about four feet into the solid rock. Above the cliffs is an undulating tract of pasture, forming a kind of step, on which is a small shallow tarn, and from this rocky slopes lead to the crest of the range, the lowest part of which, at the Passo Campolungo, is 7,595 feet above the sea. Thus the Lago Tremorgio is enclosed between two lofty spurs from the range, somewhat in the position of the seat of an armchair. The next rock-basin, the Lago Ritom! in the Val Piora, is on the opposite side of the Val Bedretto, at almost exactly the same elevation above sea-level.” Its position is remarkable. A mass of crystalline schists, calcareous, quartzose, and micaceous, with some overlying rauchwacke, are apparently infolded between two masses of gneiss, of which the southern forms a high spur separating the Val Piora from the Val Bedretto, and the northern belongs to the watershed of the Lepontine Alps. Thus the Val Piora occupies a kind of trough between these two masses of gneiss, which runs ~ 1 T was there for some time last summer, and had already paid four short visits. 2 Tt is a few inches over 6,000 feet. Professor T. G. Bonney—Lake-basins in the Alps. 17 almost from east to west, and its upper end descends from a bold craggy peak, which is called the Pizzo Columbe, and is formed of dolomitic limestone (a variety of the rauchwacke). On either side of this peak gaps, about 7,800 feet in height, lead to the upper part of the Lukmanier Road. After the first descent from these passes, the bed of the valley falls rather gradually and is fairly open, the mountains rising with moderate steepness on the southern side and precipitously on the northern. Sheltered ina recess in the latter side, just before we reach a break in the level of the valley, we find the Lago Cadagno (6,303 feet). It occupies a kind of cirque or gigantic corrie. Steep crags of gneiss sweep round about one half of it ; North. SS Ss See (—-—— a SS aS SS = | Kilometer South. Fic. 2.—Broken horizontal lines: Gneiss, with garnet and actinolitic schists (in northern part). Vertical lines: Schists, micaceous, quartzose, and calcitic. Coarse dotted: Rauchwacke. Fine dotted: Alluvial. White: Water. the western end is barred by a spur, formed of an infold of rauchwacke, followed by a mass of dark micaceous schist ; the former corresponding with a slight depression, the latter with a hill. The lake is nearly 900 yards from east to west, but a small marshy plain shows that it has once extended rather farther in the latter direction ; it is about 275 yards across. The stream draining it flows from the south-west end. The character of the ground makes it difficult to speak positively, and one or two low mounds near the stream may be morainic, but the minor ridges in the neighbourhood of the more open side are clearly live rock, and the stream itself passes over the same at a level a very few feet indeed DECADE IVY.—VOL. V.—NO. I. 2 18 Professor T. G. Bonney—Lake-basins in the Alps. below that of the lake. Hence, even if the latter to some extent is retained by drift, it may nevertheless, since it is not very shallow, be claimed as a rock-basin. A short distance from the Lago Cadagno, the level of the valley, as already stated, is interrupted by cliffs and craggy steep slopes, at the bottom of which lies the basin of the Lago Ritom, in shape something like a shortish straight sausage. The part occupied by water is rather more than two thousand yards in length, and on an average about a quarter of the width;* the upper end, now a grassy meadow traversed by streams, is rather less than a thousand yards long. The basin is bounded on the southern side by a range of gneiss—forming here the northern boundary of the Val Bedretto—which descends with moderate steepness to the lake, and slightly indents the margin of the latter with the openings of its shallow valleys. Steep grass slopes and crags of micaceous schist, becoming more precipitous towards the north, form the head of the basin, and a line of crags, at about the same elevation, extends nearly to the lower end of the delta, where they are merged in the steep slope. The basin, indeed, is bounded on all the northern side by steep grass slopes and high cliffs, outposts of the central range of the Lepontine Alps. The part visible from below consists of the dark micaceous schists,? already mentioned. The lake-basin, in fact, lies obliquely across the zone of these rocks; its upper end being not far from their northern boundary, its lower just at the southern limit. As this is approached, the slopes con- tinue steep ; the schists pass away across a range towards the lower end of the Val Canaria; the lowest part of the crest, where also some rauchwacke occurs, lying between the Pian Alto (7,428 feet) and Fongio (7,257 feet), perhaps four or five hundred feet below the latter. This mountain is chiefly composed of gneiss, and is in reality a prolongation of the gneissic range which, as already mentioned, forms the southern bank of the Lago Ritom. There the valley in which that lake lies makes at this point a sharp turn to the south, and the water is discharged through a very narrow glen —a mere gateway in the mountains; for within a few yards of the foot of the lake the stream leaps down towards the Val Bedretto in a grand series of cascades. This is practically unbroken for some hundreds of feet, since the craggy slope is extremely steep to below the hamlet of La Valle. At the above-named gateway, close to the Hotel Piora, rock can be seen on either side of the stream, obviously forming its bed. A glance at the mountains on either side shows the existence of any other outlet to be impossible. So the Lago Ritom must occupy a true lake-basin, and that a fairly deep one. 1 Professor Forel has kindly informed me that it is 2,000 métres long, 500 métres wide, and 60 métres in greatest depth. I am indebted to him for the measurements of Lago Cadagno and Tom. 2 They belong to the group which for purposes of reference I have called the Upper Schist. They are described, as well as the geology of the Val Piora, in the Quart. Journ. Geol. Soc., xlvi (1890), p. 199, ete. Professor T. G. Bonney—Lake-basins in the Alps. 19 Putting aside for the moment some questions which arise from the physiography of its borders, I pass on now to a fourth like situated on the northern flank of the Lago Ritom, at a considerably higher level. This flank, as I said, rises in cliffs and steep grass slopes. A path up the latter, near the side of a cascading stream, brings us into a small upland valley, and we presently reach a lake at its head called the Lago Tom (6,637 feet). Like the Lago Cadagno, it occupies a kind of cirque,’ and lies in the strike of the same rocks, for the enclosing crags consist of similar amphibolitic and granatiferous gneiss, and at the lower end is rauchwacke, which can be traced from the southern side of the basin of the Lago Cadagno across the intermediate spur. ‘But the Lago Tom is not only on a rock-basin but also on a very remarkable one. The lower end is dammed by a mass of rauchwacke, in shape something like a rude causeway. Its top, as a rule, is not less than 12 to 15 feet above the water, but in one place it is cut by a dry gully two to three yards wide. Still, the bottom of this cannot be less than six feet above the level of the water. Rather to the east of this gap a curving channel or inlet from the lake pierces into the barrier for some distance. Its sides are cliffs, which at its head are three or four yards high. Just on the other side of the barrier, a fairly copious stream breaks out in a shallow glen which continues the line of the dry gully already mentioned. This unquestionably drains the lake, but where it starts is not easily ascertained.* There is no distinct flow up the inlet already mentioned,*® and yet the stream, within a few feet of its issuing from the rock (a bank of old snow concealed the actual outlet), is a yard or more wide and a few inches deep, running with a brisk current. I suppose, there- fore, that the rocky bed of this inlet is traversed by a number of small fissures,’ through which the water percolates, to be collected and carried off by the stream. The rauchwacke (the usual cream- coloured, rather soft, and broken-looking limestone) is exposed in so many parts of the barrier that the existence of a drift-blocked channel seems to me an impossibility, and the Lago Tom must occupy a true rock-basin. Three out of these four lakes are situated within cirques or very precipitous corries, and if we suppose the main outlines of these to be anterior to the Glacial Age, the ice, as it descended from the ranges above, would impinge on the level floor, on which under these circumstances it might have some erosive force. The origin of the largest lake (Ritom) is less easily explained, unless we suppose that in all other respects the physical features of the neighbourhood remain practically as they were when it began to 1 Tts area is given as 1,000 square métres, and it is said to be shallow. But I should think it would not be less than some 20 feet deep, and might be more. 2 The only sign of disturbance in the lake itself, several yards away from the ~ shore, was clearly an upward flow, i.e. was produced by a strong spring in the bed of the lake. 3 I twice examined the surface of the water; on the second occasion (a very still day) I thought I detected a slight movement in some scum on the water. + Rauchwacke often has a shattered, almost rubbly aspect. 20 Professor T. G. Bonney—Lake-basins in the Alps. be formed. The Val Piora, as I have said, consists of a lower step (the Lago Ritom) and an upper step, with which the Lago Cadagno is connected. These are separated by a rocky slope, precipitous in places, nearly 300 feet high. Supposing a glacier to be descending the Piora valley, we must assume this wall to be already in existence, or it could not acquire any plunging force, and even then the fall seems hardly adequate to produce the erosion of a basin like that of Lake Ritom. Possibly, however, the ice, just at this part, may have been “jammed”; for the main glacier was probably augmented by another ice-stream, which descended a shallow, but fairly well-marked valley, leading from a gneissic peak lying south-east down to the corresponding corner at the head of the Ritom basin; while the narrow “gate” by which the water is now discharged towards the Val Bedretto would block the mass of ice above it, and this would produce more than usual friction on the bed of the valley now occupied by the lake and its delta. This basin, then, the part which les below the present contour- line of 6,000 feet (in round numbers), is the utmost that, in my opinion, can possibly be attributed to the erosive action of ice. Of this action, all the other dominant features in the surrounding scenery exhibit nothing more than superficial traces, and they appear to be due to the usual meteoric agencies. The broad outlines of the Val Piora must have been determined at an early date. It lies, as I have said, in an infold of schists, belonging to the upper part of the crystalline series, and of some rauchwacke of Triassic age, which, after crossing the lower end of the Val Canaria, reaches the floor of the Val Bedretto at and near Airolo. Regarding this simply as a fold (it is really a complicated and faulted one), the natural line for the discharge of its drainage would be towards the Val Bedretto, in the direction of Airolo, passing over the col mentioned above as lying to the north of Fongio. The top of this col is probably about 6,800 feet above the sea. Fongio itself is clearly a prolongation of the gneissic range between the Val Piora and the Val Bedretto. Hence, at some very early date, differential movements in the mountain mass must have diverted the drainage of the Val Piora from a western direction to its present outlet on the east side of Fongio, through some chance dip already existing in the range. Owing to the rapid descent to the north a groove would soon be formed, and the direction of discharge finally determined. Since then, as I suppose, all of the lower, half of the Val Piora that lies below the contour- line of 6,800 feet (in round numbers), with some of the upper, must have been excavated. Somewhat beneath this level, perhaps at about 6,500 feet, a rather marked increase of steepness is often perceptible in the slopes on the northern side of the lower part of the Piora valley. Besides this, a structure which is conspicuous in the Val Bedretto itself may not be without significance. Looking up that valley from such a point as the top of Fongio, one perceives that the slopes become near a certain part very much steeper, and begin to descend from that level rather abruptly towards the bed of Jukes-Browne & Milne—Oretaceous Fossils in Aberdeenshire. 21 the valley. On the. right bank of the Val Bedretto we can trace this terrace-like configuration for a long way below the opening of the Val Piora, and opposite to that gap I estimated its height as much the same as that of the pass north of Fongio, i.e. not far from 6,700 feet. On the left bank, it will be remembered that, at the opening of the Val Tremola, the slope markedly changes, perhaps a thousand feet lower down.? I have observed this structure in many of the uppermost portions of the Alpine valleys, often some couple of thousand feet, perhaps occasionally rather more, above the present floor. It must indicate some very marked change in the erosive agents, probably an increase in the velocity of the torrents, since the valley becomes much.more steep-sided. Can it possibly indicate the results of the Pre-Pliocene set of disturbances ? But this is venturing into the realm of speculation; my present purpose is to show that, although doubtless many tarns and lakelets have no real claim to be called occupants of rock-basins, a few such do really exist.* V.— On rHe Cretaceous Fossins FounpD at Morgszxat, ABERDEENSHIRE.’ By A. J. Juxes-Browne and Joun MItne. 1. Generat Report py Mr. Joun Mine. ORESEAT is in the parish of Cruden, in the east of Aberdeen- shire. It lies at an elevation of 300 feet above sea-level, and the surface of the ground slopes to the sea at Cruden Bay, distant five miles to the- south. On the north the ground rises gradually, reaching the height of 450 feet above sea in Torhendry Ridge, which is strewn with chalk-flints in great abundance. Previous Investigations.—Geologists are indebted to Dr. William Ferguson, of Kinmundy, for the earliest notices of Greensand at Moreseat. In 1839 an excavation 14 feet deep was made for the water-wheel of a mill, and a drain away from it, on the south side of the farm steading, a little below the 300-feet level. The excavation was made in clay, and in it were found layers of sand- stone containing many fossils. The Rev. J. Johnstone, Belhelvie, who lived at Moreseat at the time, says that the discovery excited great interest, and that Moreseat was visited by scientific men, amongst others by Professor Knight, of Marischal College and University, Aberdeen, who communicated with Dr. Thomson, of Glasgow University, on the subject, and informed his class 1 The slope, above Fiesso, begins of course just below the Lago Tremorgio, or nearly at 6,000 feet. 2 No doubt this has been subsequently cut down below the original level, the valley being a large one; the Val Canaria has been cut yet lower. 8 IT believe I know of others than those mentioned in this paper, but, as I have not examined them since Mr. Marr’s paper was published, will not refer to them. 4 Report of the Committee, consisting of T. F. Jamieson (Chairman), A. J. Jukes-Browne, and John Milne (Secretary), appointed to ascertain the Age and Relation of the Rocks in which Secondary Fossils have been found near Moreseat, Aberdeenshire. 22 Messrs. Jukes-Browne and Mine— of 1839-40 that Greensand had been discovered at Moreseat. Dr. Ferguson was a student in this class, and thus had his attention directed to the Moreseat fossils from the first. Hundreds of loads of clay were removed from the excavation, and many fossils were collected; but when the wheel was put in and built up, and the drain was covered up, there remained no trace of the interesting discovery. In 1849, on making a deep ditch alongside a road to the north of the farm steading, and a little above the 300-feet level, the same clay, sandstone, and fossils were met with. Dr. Ferguson sent a notice to the Philosophical Society of Glasgow.’ Next year he visited the newly-made ditch, and sent an account of the original | discovery and a description of what he saw to the Philosophical Magazine.” Dr. Ferguson’s description of what he saw is quoted here, because it exactly coincides with what was seen in subsequent excavations. ‘An excavation about 7 feet in depth was made, and the section presented irregular layers of unctuous clay, of a dark-brown colour and soapy feel, and so tough and adhesive as to render it a work of considerable labour to dig it out. Inter- stratified with this clay were thin layers of a compact sandstone. These layers of sandstone were not continuous; they graduated into each other, thinned out, disappeared, and reappeared most confusedly. They were very much inclined, dipping towards the south. The whole mass had much the appearance of having been drifted; although from the nature of the matrix, and the state of preservation in which the shells are found, it does not appear as if it could have been drifted far. The sandstone is tough and soft when newly dug, but hardens on exposure to the air and becomes light-coloured in drying. When wet, it presents a mottled appearance, the colour being greenish; when dry, this almost disappears.” In 1856 a collection of fossils from Moreseat made by Dr. Ferguson was examined by Mr. J. W. Salter and Mr. W. H. Baily. An account of them was published next year in the Quarterly Journal of the Society, along with a note by Dr. Ferguson. Mr. Salter regarded the Moreseat fossils as an indication, in the near neighbourhood, of Upper Greensand in sitd. ‘Types of these fossils are preserved in the Museum of Practical Geology, Jermyn Street, London. 7 In the memoir descriptive of the sheet of the Geological Survey containing Moreseat, notice is taken of the Greensand fossils found there, and of the Chalk-flint fossils found at Bogingarrie, a few miles to the south-west, also described by Mr. Salter; but the surveyor does not say that he saw at Moreseat any fossils or fragments of Greensand sandstone. In 1894 the Secretary of the Committee was lecturing at Cruden on Geology and Agriculture for the Aberdeen County Council, and was induced by the mention of Greensand in the memoir to visit 1 See Proceedings of the Society, vol. iii, 1849. 2 See vol. xxxvii, 1880. Cretaceous Fossils found in Aberdeenshire. 23 Moreseat and make inquiries; but he could learn nothing further than that fossils had been found in the excavation made for the mill-wheel, and as it was enclosed with masonry nothing could be seen. He visited the place repeatedly and examined all the ditches and watercourses on the farm, but found no fossils. The reason of this was seen afterwards. When pieces of the sandstone were exposed to frost they became a soft paste on thawing, and all trace of the fossils they contained disappeared. He afterwards met with Mr. Alexander Insch, Peterhead, who had heard that fossils had been found north of the farm steading. Accompanied by him and Mr. D. J. Mitchell, Blackhills, Peterhead, he again visited Moreseat. An excavatiqgn was made to the north of the ditch seen by Dr. Ferguson, and after passing through a foot or eighteen inches of sandy ‘clay, thin layers of sandstone with fossils were found. The appearance of the layers of sandstone was peculiar. They conveyed the idea that they were cakes of some plastic material spread out in a soft state, yet not wet enough to bear great lateral extension without cracking. The layers were full of vertical cracks, which broke them up into small fragments. These might have been caused by shrinking on drying, as the excavation was made where the ground would be dry in summer. The method of occurrence was the same as that described by Dr. Ferguson already quoted. The fossils found were chiefly casts of shells. Specimens were forwarded to the British Association with an application for a grant of money to ascertain by deeper excavation whether the bed from which the sandstone had come could be found there. Though the application was unsuccessful, digging was con- tinued by Messrs. Mitchell and Insch, who collected a large quantity of fossils in various places over an area a quarter of a mile broad in the neighbourhood of Moreseat. In 1895 specimens were sent to Dr. H. Woodward, of the British Museum (Natural History), London, with another application for a grant from the British Association. A grant of £10 was given, and the Committee already named was appointed. Professor J. W. Judd, of the Royal College of Science, South Kensington, was consulted about the specimens already collected by Messrs. Mitchell and Insch, and by his advice they were sent to the Geological Survey Office, where they were examined and compared with Dr. Ferguson’s typical specimens by Mr. G. Sharman and Mr. HE. T. Newton. They published a statement of the result in the Guonocgicat Magazinu, Dec. IV, Vol. Ill, 1896, p. 247. They came to the conclusion that the specimens had “been derived from beds where a large part of the Cretaceous series of strata occurs; not only Upper and Lower Chalk and Upper Greensand, as pointed out by Salter, but also beds of Lower Greensand or Speeton Clay age.” In making this statement they seem to have referred not only to the specimens collected by Messrs. Mitchell and Insch, but also to the Chalk-flint specimens in the Ferguson collection. It may therefore be noted that though flints are fouud 24 Messrs. Jukes-Browne and Mine— in great abundance on the ridge above Moreseat, they become fewer in going down the hillside, and are comparatively scarce at Moreseat, and it may be assumed that none of the flint-fossils in the Ferguson collection were found in the immediate neighbour- hood of the Greensand fossils. Work of the Committee.—On being made aware of their appoint- ment the Chairman and the Secretary met on the ground, accompanied by Messrs. Mitchell and Insch. Mr. Johnstone, the proprietor of the farm, kindly consented to allow an excavation to be made. All the places where fossils had been found were examined, and it was resolved to sink a shaft at the highest place where they were certainly known to be, in the belief that the fragments of sandstone had been moved from a higher to a lower level. The place selected is on a knoll north of Moreseat, about 330 feet above the sea-level, and about a quarter of a mile from the place where fossils were found in 1839. The ground to the north is covered with peat-moss overgrown with heather, and nothing can be seen of its character. Half a mile to the north-east there is some cultivated land, and a pit had been sunk by a crofter for a pump in white unstratified siliceous matter, apparently detritus of chalk-flints. To the north-west another pit had been dug. At first glacial drift clay was met with, then fine stratified sand, unsuitable for a pump well, and the excavation was stopped at 14 feet deep. This hole was 50 feet above the site selected for the shaft. It was thought best to defer the sinking of the shaft till the following summer to avoid risk of obstruction from water. Mr. J. T. Tocher, the Secretary of the Buchan Field Club, which is affiliated to the British Association, undertook to contract for the work, and along with Mr. Mitchell to visit it while in progress, and to examine the material excavated. The shaft was dug in the summer of 1896, and a depth of 30 feet was attained. The first foot consisted of ordinary soil. Below it was found a yellowish-brown sandy clay mixed with small fragments of sandstone and pebbles of quartzite and flint. The sandstone was afterwards found to contain Glauconite, and may be termed Glauconitic Sandstone. Almost every fragment yielded fossils, mostly casts of small shells. At 3 feet the clay became finer and the sandstone fragments more abundant. At 4 feet they were in layers among the clay, gradually thinning out and disappearing, as described by Dr. Ferguson. At 5 feet, on the south side of the shaft, a deposit of fine white sand was found, in which were pebbles of granite, quartzite, and flint. In the other part of the shaft the clay continued, with numerous bits of the grey glauconitic sandstone in a layer, much broken, dipping to the south, which is the direction of the slope of the surface of the ground at Moreseat. The mass of sand increased down to 8 feet, where it ended. At the bottom of the sand there was a block of granite a foot in diameter, and under it a large flint pebble. At 10 feet there was, on one side, a mass of black clay Cretaceous Fossils found in Aberdeenshire. 25 with a soapy feel, in which sandstone fragments, much worn, were found. This black clay stopped at 11 feet. At 14 feet it began to appear again, and to take the place of the yellowish- brown clay, which ended at 16 feet. The lower part of it contained many stones. From this level the black clay continued all the way down to 80 feet, where it was succeeded by red laminated clay, without stones of any kind. The black clay con- tained large stones of granite and quartzite and small fragments of the glauconitic sandstone all the way, but the stones grew fewer in number the deeper the shaft was sunk, and the sandstone fragments had almost ceased at 27 feet. The excavation could not be carried farther than 80 feet, because, on reaching the red laminated clay, water began to come in and the funds were exhausted. . The Committee regret that they were unable to ascertain the nature of the solid rock under the shaft. Most likely it would have been found to be granite, the rock seen at the sea-coast from Cruden Bay to Peterhead. The shaft was evidently in glacial drift clay all the way, and therefore the sandstone fragments were not in sitt, but had been transported, apparently from the north. By a series of pits a few feet deep made in this direction it might be possible to follow the sandstone farther up the hill, and a shaft sunk at the uppermost place where they could be found might discover the bed from which they came; yet the Committee cannot venture to express a confident opinion that another excavation would be more successful than the last in finding the origin of the Glauconitic Sandstone. Many appearances indicate that the latest changes on the surface of the ground in the district in which Moreseat is situated were caused by local glacial sheets, perhaps not on a great scale, yet capable of moving great quantities of loose and soft matter. The white sand in the shaft seemed to have been moved bodily from a bed seen to the north-west at a higher level. The original seat of the Glauconitic Sandstone may have been to the north of the shaft, a little farther up the hill, and yet the bed may have been entirely removed by ice descending the hill. If, however, the British Association renew the grant, the Committee will be happy to make another attempt to find the origin of the Moreseat fossils. Mr. Tocher, F.I.C., analyzed the clays found in the shaft, and ascertained that the reddish colour of the one was due to ferric oxide of iron, and the black colour of the other to ferrous oxide. Mr. Insch collected a large quantity of sandstone fragments containing fossils. These were examined by Mr. A. J. Jukes- Browne, and will ultimately be deposited either in the Aberdeen University Museum or in that at Peterhead. 2. Report on tHe Fossins sy A. J. JuKES-Browne, B.A., F.G.S. The existence of Cretaceous fossils, embedded in a kind of ‘*Greensand,” and found at Moreseat, near Aberdeen, has been known to geologists for nearly fifty years. Mr. W. Ferguson 26 Messrs. J Pie MBG and Milne— discussed them in a paper read before the Philosophical Society of Glasgow in 1849, and subsequently communicated to the Philosophical Magazine." In this he observes that most of the remains are casts, and he mentions the occurrence of several species of Ammonites and Belemnites, as also of Cardium, Terebratula, Trochus, Solarium, Cerithium, and Spatangus. Some of Mr. Ferguson’s fossils were examined and named by Mr. J. W. Salter in 1857,? who gave a list of fourteen species, two of them being Ammonites doubtfully referred to—Am. Selliguinus, Brong., and Am. Pailletianus, D’Orb. Four of the others he describes as new species, and from the remaining six he comes to the conclusion that the fauna is of Upper Greensand age. From 1857 to 1896 no further light was thrown on the subject, but in the latter year some of the fossils collected by Messrs. Mitchell and Insch were submitted to Messrs. Sharman and Newton, who made a careful examination of them, and communicated the results to the GeoroGicaL Magazine. They compared these fossils with the specimens described by Salter, which are preserved in the Museum of Practical Geology, and found the matrix to be the same. They also state that though slight differences are noticeable in different pieces of the rock, yet all the samples are “so similar that one can scarcely question their having been originally derived from the same bed.” They found, however, that many of the fossils could not be identified with any Upper Greensand species, but were Lower Cretaceous forms, many of them identical with those occurring in the Speeton Clay. They admitted, however, a few species which occur in the Upper Cretaceous series only, and have not been found in any British Lower Cretaceous deposit. Hence they conclude “that the faunas which in the south mark the distinct horizons of Lower Greensand, Gault, and Upper Greensand are here in Aberdeenshire included in one bed of nearly uniform character throughout.” This conclusion certainly invested the Moreseat fossils with still greater interest than they possessed before. A collection of the fossils was sent to me by the Rev. John Milne in September, 1896, but it was impossible for me to examine them in time to report on them before the meeting of the British Association in that year. I have since, however, given them careful attention, and have received much assistance from Messrs. Sharman and Newton, whose previous acquaintance with many of the species has saved me much time and labour. It is not an easy task to identify these Moreseat fossils, for they are all in the state of casts and impressions. In no case does any actual shell or test remain, but the firmness of the rock has in most cases prevented the enveloping matrix from being pressed down on to the internal cast, so that the external cover generally retains the shape and impression of the original shell, and a mould ! Phil. Mag., vol. xxvii, p. 430 (1850). ? Quart. Journ. Geol. Soc., vol. xiii, 1857, p. 83. 3 Gzou. Mae., Dec. IV, Vol.-III, 1896, p. 247. Cretaceous Fossils found in Aberdeenshire. 27 can, if necessary, be taken from it. The fossils had been carefully collected, and as both casts and covers had been transmitted, it has been possible to determine many of the species. _ Before discussing the species, however, the rock itself merits description, for its peculiar characters seem to have escaped previous observers. To the eye it presents itself as a very fine-grained siliceous rock, resembling malmstone, dark grey when damp and freshly broken, drying to a lighter grey. Fractured surfaces often show spots and patches of darker material than the rest of the mass. Under the lens it showed a finely granular matrix, containing many small grains of glauconite and numerous flakes of mica, with small patches of a yellowish-green mineral which is apparently a decom- position product. The general aspect and light specific gravity of the rock led me to suspect the presence of colloid silica, and accordingly I sent specimens to Mr. W. Hill, F.G.S., for microscopical examination. Mr. Hill cut slices from two of these, and furnishes me with the following account of the structure exhibited by them :— “The material of both slides is alike, and compares most nearly with the micaceous sandstone of Devizes (Upper Greensand). The ground- mass consists of amorphous and semi-granular silica, neutral to polarized light, with little or no calcite. There are many sponge spicules, the walls of which have mostly disappeared, but which are outlined in the matrix. The space once occupied by the spicule is often partly filled with globules of colloid silica, like those in malmstone described by Dr. Hinde,’ and similar globules are dispersed through the mass of rock. There is much quartz sand in small, angular, even-sized grains, but not so much as in Devizes sandstone. Glauconite grains are also abundant, but the quantity varies much in different parts of the rock; the grains seem to be breaking up, and are often seamed with vein-like markings. There are also larger patches of dirty-green material, which has a somewhat indefinite outline, and may be of secondary formation. Small flakes of mica are scattered through the slides, but it is only when these are cut transversely that the mineral can be easily identified.” ‘From the above description it will be seen that the rock may be termed a gaize—that is, a fine-grained sandstone, in which colloid silica is an important ingredient ; this is not a common rock, and in England it is only known as occurring in the Upper Greensanil in association with malmstone. In France a gaize of Lower Gault age, containing Ammonites mammillatus and Am. interruptus, occurs in the Ardennes (Draize), but [ can find no record of the rock occurring in the Lower Cretaceous series either in France or Germany. The formation of gaize and malmstone probably took place in clear water of a moderate depth; it is not a shallow-water deposit, and yet it was deposited within the range of a current which carried ? Phil. Trans. Roy. Soc. 1885, pt. ii, p. 403. 28 Messrs. Jukes-Browne and Milne— fine sand. The abundance of sponge spicules shows that the con- ditions were such as to favour the growth of siliceous sponges. Remarks on some of the Fossils. The collection sent to me includes some species which have not yet been recorded from the Moreseat rock, and as these are all Lower Cretaceous forms, the Vectian element in the fauna is clearly very strong—so strong indeed that I am led to doubt the existence of some of the Upper Cretaceous species which have been supposed to occur. I shall therefore offer some remarks on certain species, and give a complete revised list of the Moreseat fauna, so far as it is at present known. Micrabacia coronula, Goldf.—This identification requires confirma- tion. It depends solely on Salter’s authority, for the specimen he saw is not in the Jermyn Street Museum, and no other specimen has been detected in the collections recently made. The species 1s not known to occur below the Upper Greensand zone of Pecten asper, and would be difficult to recognize from a cast only. Echinoconus castanea, Brong.—This also requires confirmation, for the specimen so named by Mr. Salter has not been found at Jermyn Street, and no other example has been seen. In England its earliest appearance is near the top of the Upper Greensand, but in Switzerland it ranges down to the base of the Gault (see De Loriol in “ Echinologie Helvétique”’), so that it may in some localities range even lower. No species of Echinoconus, however, has yet been recorded from rocks of Lower Cretaceous age. Discoidea decorata(?), Desor.—This specimen was among those sent by Mr. Milne. It consists of a nearly perfect external mould in two parts. It differs from D. subucula in having close-set rows of nearly even-sized tubercles, eight rows on the inter- ambulacral areas, four on each set of plates, and four rows on the ambulacral areas; but the two inner ambulacral rows do not reach either to the apex or to the peristome. The mouth and vent are both rather large. In these respects it agrees with D. decorata. Mr. C. J. A. Meyer having informed me that he possessed specimens of a Discoidea from the Vectian of Hythe, the Moreseat Specimen was sent to him for comparison. He reports that it agrees with those from Hythe, but he is doubtful whether they are referable to D. decorata, Desor, or D. macropyga, Ag. Both are Lower Cretaceous species. Rhynchonella compressa.—The specimen so named by Salter is at Jermyn Street, and has been examined again by Messrs. Sharman and Newton, with the result that they think it is only a compressed variety of Rh. sulcata, Park. As specimens of Rh. sulcata are not uncommon at Moreseat, and as it is a very variable form, Rh. compressa may safely be excluded from the list. Waldheimia faba, D’Orb. (non Sow.).— One specimen apparently referable to this species is among those sent to me. As it is only Cretaceous Fossils found in Aberdeenshire. 29 a cast and as the shell is smooth, one cannot be quite sure of the species, but the shape is well preserved, and I am indebted to Mr. Meyer for pointing out that it has the squareness towards the front which is characteristic of the species in question. This is well shown in the example figured by Davidson (‘Cret. Brach.,” vol. iv, pl. vi, figs. 12-14), which came from the Speeton Clay of Knapton in Yorkshire. Tima semisulcata, Sow.—This species has appeared in previous lists on the authority of Mr. Salter, but the specimen is in the Jermyn Street Museum, and Mr. Newton informs me that it is only an internal cast, and may, with equal probability, be referred to L. Dupiniana. As specimens of the latter do occur, and none referable to L. semisulcata have since been found, I think this Upper Cretaceous species may be omitted from the list. Arca securis, D’Orb.—I have ventured to enter the common Arca of the Moreseat sandstone under the name of securis instead of under carinata, because the specimens I have examined seem to me to come nearer to securis, and Mr. Meyer, to whom a specimen was sent, is of the same opinion. The two species are so closely allied that some paleontologists regard them as identical; but there are slight differences, and Messrs. Sharman and Newton agree with me in considering the Moreseat specimens to be smaller and shallower in the valve than the ordinary A. carinata of the Upper Greensand ; and in these respects they resemble A. securis. In some of them, moreover, the ribs on the posterior area are like those in D’Orbigny’s figure of securis; so that, if the forms are separable, I think these should be listed as securis. Leda scapha (?), D’Orb.—I have seen two casts which probably belong to this species, though they equally resemble L. Marie of the Gault, for, as Mr. Gardner has remarked, there is very little difference between these species. Pectunculus umbonatus, Sow.—This is another of Mr. Salter’s identifications, and unfortunately it also is only an internal cast. There are several species of Petunculus to which such a cast might belong, but the probabilities are against its being P. umbonatus. As no other specimen has occurred among the fossils recently collected, it will be best to leave it without a specific name for the present. Turbo. Triboleti (2), Pict. and Camp.—There is one specimen, a portion of the external impression of the shell, showing an ornamentation closely resembling that of Turbo Triboleti, which is a species from the Upper Gault of Ste. Croix. This specimen was sent to Mr. Meyer, who informs me that he has an imperfect specimen from the Vectian of the Isle of Wight which it equally resembles. Ammonites flexisulcatus (?), D’Orb.—A small Ammonite was found in breaking up a lump of the material sent to me, and was 30 Messrs. Jukes-Browne and Milne— forwarded, with other specimens, to Messrs. Sharman and Newton. They reported that it most resembles A. flewisulcatus, though the portion preserved is smooth and without sulcations. ! Nautilus sp., Sow.—Among the fossils sent to me by Mr. Milne is the cast of a Nautilus, badly preserved, but showing strong transverse rugations or ribs like those of N. radiatus, but its condition is such as to prevent any certainty of identification. Mr. A. H. Foord has kindly examined the specimen, but could not venture to name it. a g Re eS en Bd | 22 eos| a |e qe s poe i Om 5 m Bes 229 Be Ge Moreseat Fossils. piel g S BEG ESN BS |ES aeoiies) |e joc Actinozoa. Coral (like Micrabacia) Echinoderms. Dp. Ananchytes (? Cardiaster) Te |) Ws Discoidea decorata, Desor (?) # p- Kchinocyphus difficilis, Ag. * p. | M. Enallaster Scoticus, Salter p- Echinoconus castanea (?) * * * Annelida, p- Serpula, sp. Polyzoa. p- Entalophora (?) Brachiopoda. p- | M. Rhynchonella suleata, Park. * # * Dp. Terebratula, sp. M. Terebratella (cast only) M. Waldheimia faba, D’Orb. (non Sow.) * Pp. », hippopus var. Tilbyensis, Dav.| Lamellibranchiata. M. Anatina, sp. p. | M. Area securis, D’ Orb. # p. », Raulini (?), D’Orb. * ? 1S |) ML Astarte striato-costata, Forbes # p- | M. Avicula simulata, Baily p- |M.? Cardium Raulinianum, D’Orb. — # x M. Cardium, sp. (cast only) 106 Corbula, sp. p. | M. Cyprina Fergusoni, Salter To |) AWE Exogyra (small species) D- Gervillia solenoides, Defr. * # # p- e near to rostrata p- Goniomya, sp. p- Tnoceramus, sp. M. Leda scapha, D’ Orb. * p- Lima Dupiniana, D’Orb. # M. », longa (?), Rom. # D- », near to abrupta, D’ Orb. p. | M. Limopsis texturata, Salter p. | M. Lucina, sp. M. Ostrea frons (?), Park. (carinata, Sow.) | # * * p- Panopea, sp. | p- | M. Pecten orbicularis, Sow. 2 Es # * Dp. Pectunculus, sp. Cretaceous Fossils found in Aberdeenshire. ol za |e GoglS Ie ves 28 \s8 oa| & |One| ess Be]. Moreseat Fossils. 25 8 8 gs 3 ge S Sisis Oew = S Se Bo |5° BOOL § se | [Ss = is} p: | M. Pinna tetragona, Sow. # * # [De || WL. Plicatula placunea, Lam. # P) p- Spondylus, sp. M. Tellina, sp. M. Thetis (?) P- Trigonia Vectiana, Lyc. # M. Ae sp. Nov. 6 M. Venus Brongniartina (?), Leym. # Gastropoda. D- Acteon, sp. p. | M Cerithiam aculeatum, Forbes MS. * p-|M Dentalium ccelulatum, Baily Dp: Phasianella (like ervyna, D’ Orb.) M. Solarium, sp. p. | M. Trochus pulcherrimus * Dp: SDs eke Turbo Triboleti (?), P. & C. # * Cephalopoda. M. Ammonites flexisulcatus (?), D’ Orb. % p. | M. i Mortilleti, P. & Lor. x p. | M. 99 Speetonensis (var.) % Dp: 55 Selliguinus (?), Brong. * Pp: Belemnites, sp. Pp: Crioceras Duvallii, Lév. # M. Nautilus, like radiatus, Sow. o- It only remains to indicate the conclusion to which the study of the Moreseat fossils has led me. . Of the species enumerated by Mr. Salter in 1857 four have been omitted from the preceding list, being regarded as doubtful identifi- cations which have not been confirmed by subsequent discoveries. Of the three genera of Echinoderms mentioned by him the Discoidea was probably the species which resembles D. decoraita, and the two named respectively Diadema and Ananchytes may have been Lower Greensand forms for anything that we know to the contrary. The number of named species available for comparison with other faunas is now 33. Out of this total no fewer than 25 are species of Lower Cretaceous age, and only 7 of these range into the Gault ; 5 are species which have not been found elsewhere, 2 are Upper Greensand species, but one of these is a doubtful determination, and 2 are Ammonites, of which the identification is also doubtful. There is therefore an overwhelming proportion of exclusively Lower Cretaceous species, namely 18 to 2, while out of the 6 Cephalopods 5 are exclusively Lower Cretaceous forms, the only one which is not being the very doubtful 4m. Selliguinus. The occurrence of one Upper Greensand HEchinoderm (Hchino- cyphus difficilis), and the possible occurrence of another ranging o2 Professor Spencer— Continental Elevation. from Lower Gault to Chalk (Hchinoconus castanea?), is hardly sufficient evidence to warrant the conclusion that a part of the rock-mass was of Upper Greensand age. There is nothing except the Am. Selliguinus that is specially characteristic of the Gault, and the question is this: What is the evidential value of the occurrence of Hchinocyphus difficilis, and possibly also of Hchinoconius castanea (?)? I think it may be answered in this way: it is more reasonable to suppose that these two species, or forms very closely allied to them, date really from Lower Cretaceous times, than it is to suppose the deposition of exactly the same kind of rock material should have continued at any one place from the time of the Lower Greensand to that of the Upper Greensand. In other words, I believe that the rock-mass from which the Moreseat fossils have been derived was entirely a Lower Cretaceous rock, but high in that series, and corresponding approximately to the Aptien stage of France, and to the Lower Greensand or Vectian of the Isle of Wight. VI.—Ow tHe ContTiInenTAL ELEVATION OF THE GLACIAL PERIOD. By Prof. J. W. Spencer, M.A., Ph.D., B.Sc., F.G.8. ConrTENTs: Introduction.—Character of the Submarine Antillean Valleys.—Gradients of Sub- marine Valleys.—Date of the Continental Elevation.—Migration of Mammals.— © Submarine Channels off the Eastern Coast of America.—Submerged Plateau of the North Atlantic.—Continental Elevation a Cause for Glacial Climate. Introduction. EFORE the last meeting of the British Association, held in Liverpool, Professor Edward Hull presented a paper upon “Another Possible Cause of the Glacial Epoch.” In that paper, Professor Hull applied the writer’s work on the ‘ Reconstruction of the Antillean Continent,”? which brought together evidence of great continental elevation. This elevation and its effects upon the ocean-currents, in diverting them from the West Indian regions, with the consequent reduction of their temperature as they reach the northern latitudes in conjunction with the elevation of the land, were thought by Professor Hull to be sufficient causes for the production of the glacial climate over temperate regions in late geological times. The writer has hitherto never applied his observations on high continental elevation to climatic changes ; but in this paper he proposes to extend briefly his researches from the Antillean region to the higher latitudes of America and the North Atlantic regions. Something has also been learned of the date of the great elevation; consequently inferences may be drawn as to climatic changes. Character of the Submarine Antillean Valleys. The feature of the paper on the “ Reconstruction of the Antillean Continents,” and subsequent observations of the region, show that — 1 J. W. Spencer, ‘‘ Reconstruction of the Antillean Continent’’ : Bull. Geol. Soc. Amer., vol. vi, pp. 103-140, 1894. Professor Spencer—Continental Elevation. I) there are deep valleys, often of great length, extending from the mouths of the existing rivers, and crossing the American coastal plains, over deeply-buried channels. These are plainly recognizable in soundings upon the submarine coastal plateaux, and amongst the banks and islands of the neighbouring West Indian seas, to depths of 12,000 feet or more, before reaching the oceanic floors. The drowned valleys radiate from the continental margins and extend in a direction across that of the coast, and the mountain ranges to the back of it. Their courses do not usually coincide with those of the mountain folds. These submarine valleys are often recognizable for hundreds of miles in descending to the floors of the ocean-basins, as may be seen amongst the Bahamas. Frequently the divides between different systems are themselves submerged, as in the Straits of Florida. The submerged valleys are no broader than those of existing rivers, such as those of the Amazon and the St. Lawrence, nor indeed are they usually as wide. The Colorado canon, from five to twelve miles across, between walls of 2,000 feet in height, is wider than some of the drowned valleys, which in part are canon-like. Both the submarine plateaux and the floors of the valleys are like comparatively level plains or base-levels of erosion, which represent pauses when the streams and atmospheric agents could not further deepen their valleys, but only broaden them out into plains, until a subsequent elevation of the region permitted the streams once again to deepen their channels. Gradients of Submarine Valleys. The gradients of the submerged valleys (except along the reaches crossing extensive plains, now below sea-level) can only be com- pared with those of plateau regions, and not with the slopes of such a river as the Mississippi, which flows over great plains at low elevation. The manner in which the valleys descend from one platform to another is illustrated in the plateau region of Mexico and the West. An example of the declivity of such valleys may be seen along the Mexican Railway, back of Vera Cruz, and another above Monterey. The land valleys are made up of a series of steps with greater declivities between them than occur between those submerged. The various platforms represent the rise of the land during the excavation of the valleys. The gradients of the sub- merged plateaux are frequently as small as, or smaller than, those of such plains as the Mississippi, while the declivities at their margins are less abrupt than those of the land valleys descending from tablelands, as may be seen by comparing them with the Mexican valley sections. The gradient of the Colorado river, in its canon 3,000 feet deep, is greater than that of the submerged platforms. Besides the greater valleys, descending from the high plateaux, there are many short tributaries, heading in amphitheatres, -where the slopes may be from 200 to 600 feet per mile; the whole resembling gigantic “‘ wash-outs.” So also similar short drowned valleys occur on the edges of the submarine plateaux. The data concerning these comparative declivities were not obtained when the DECADE IV.—YOL. V.—NO. I. 3 34 Professor Spencer—Continental Elevation. original paper upon the submarine river-like valleys was prepared, but they now greatly strengthen the inferences that the drowned plateaux may be used as “ yardsticks” for measuring the amount of late continental elevation. In his paper referred to, Professor Hull endorses the correctness of the interpretation that the submerged valleys were formed by atmospheric agents. Such inferences being correct, the West Indies formed a high continental plateau, while the Gulf of Mexico and the Caribbean Sea were plains or inland lakes draining into the Pacific Ocean across what are now low passes of Mexico and Central America. Date of the Continental Elevation. Elsewhere the writer has shown! that the old Mio-Pliocene surfaces extended much beyond their present limits, and were subjected to long-continued reduction to base-levels of erosion. Upon the undulations of the country then produced, the Lafayette deposits of the continent form an extensive mantle, which has been provisionally considered as belonging to the late Pliocene epoch. The surfaces are enormously denuded. Following this formation northward, although there are but few exposures of contact, the writer has observed near Somerville, N.J., the Lafayette overlain by a few feet of glacial drift, which has been extensively denuded, as it is locally wanting. Resting upon the boulder drift, and where ~ this has been removed, upon the underlying Lafayette loams and gravels, the Columbia formation may be seen. This feature shows that the epoch of glacial deposits occurred between the Lafayette and Columbia periods. Consequently, the epoch of great elevation, which favoured the excavation of the valleys, coincided with that of the glacial deposits of the early Pleistocene days. Migration of Mammals. The Antillean Continent formed a bridge connecting North and South America, over which only a few mammalian remains have been found, as the greater portion of it is now beneath the sea. At Port Kennedy, Pennsylvania, an extensive fauna has been discovered in fissures, and upon it Professor Edward D. Cope was engaged at the time of his recent death, but some results he had made known. Of 38 species of mammals, so far determined, a large percentage are extinct, and among these occur Hquus and Megalonyx. ‘There is also an abundance of remains of an old form of South American bear, which are not known to have crossed the plains of the West. The occurrence of these types at Port Kennedy, Professor Cope regarded as strongly supporting the theory of the Antillean bridge in the early Pleistocene epoch. There is also a newer cave-fauna in Eastern North America, which belonged to a later period, separated from the first by a partial submergence, according to the conclusions of that distinguished author. Hlephas has recently been found in- Guadeloupe. 1 «Reconstruction of the Antillean Continent,’’ cited before. Professor Spencer—Continental Elevation. 35 Submarine Channels off the Eastern Coast of America. The submerged valleys, which are best developed among the Bahamas and off the adjacent portions of the continent, provide the key for interpreting the submarine features of other regions. The broad subcoastal plain off the south-eastern States becomes narrowed to a few miles east of Cape Hatteras; but northward it broadens again, and eventually reaches a width of nearly 300 miles south-east of New England, and more than that across the submarine plateau which forms the Newfoundland banks. East of Labrador it has a considerable breadth, but the soundings there are too scanty for its delineation. In drawing the contours at a considerable distance apart, the same forms of indentation are repeated in the borders of the plateau as those observed farther south; but where the contours are drawn close together (even where the soundings are not as numerous as is desirable), the deep valleys are found to be con- tinuations of existing rivers. Thus, Lindenkohl! traces the Hudson River channel to a depth of 2,852 feet, and the Great Egg Harbour channel to 2,334 feet, where the plateau is submerged only 600 feet. The Delaware and the Susquehanna valleys are also recognizable on the subcoastal plain to depths of about 3,000 feet. In 1889, the writer showed how the Laurentian valley was submerged for a distance of 800 miles, beneath the waters of the Gulf of St. Lawrence, with the channel from 1,200 to 1,800 feet below the surface of the sea; but near the edge of the drowned plateau it descends abruptly to a depth of 3,666 feet.2 The same is true of the valleys crossing the New England, Nova Scotia, and the Newfoundland banks. From the edge of the continental shelf, the Susquehanna valley descends precipitously to a depth of more than 9,000 feet, with its valley recognizable to 12,000 feet. The Delaware descends abruptly to 6,066 feet, and is plainly traceable to 11,256 feet, and to greater depths beyond. The same is true of the Hudson and its tributaries from Connecticut, being recognizable to depths of more than 12,000 feet. From the borders of Massachusetts, Nova Scotia, and the Newfoundland banks the valleys descend pre- cipitously into amphitheatres 6,000 or 7,000 feet below the surface, and continue to depths of 12,000 feet, and in some cases to even 15,000 feet. While to an unknown extent the drowned plateaux are covered with Tertiary formations, still the submerged valleys must, to a considerable extent, have been excavated out of hard Paleozoic and older strata, thus producing variations in the lengths of the deeper channels, and forming a contrast with some of those of the Antillean region. From analogy with land valleys, the channels crossing the sub- marine coastal plains of a few hundred feet, afterwards of perhaps 3,900 feet, represent a long period of elevation. Then followed the 1 American Journal of Science, vol. xli, p. 490, 1891. 2 J.W. Spencer, ‘‘ High Continental Elevation preceding the Pleistocene Period’? : Bull. Geol. Soc. Amer., vol. i, p. 6, 1889. 36 Professor Spencer— Continental Elevation. great elevation of perhaps two miles or more in height, continuing only long enough to allow the streams to dissect the margins of the tablelands, and form amphitheatres belonging to the new base-level of erosion. While the great depressions shown in the soundings may have in part been occasioned by an exaggerated oceanic sub- sidence along the line of the continental margin, yet amongst the West Indies it has been found that the actual depression has exceeded two miles. Although the deeper valleys of the north may be less than a hundred miles in length, their slopes are no greater than those of the valleys descending from the Mexican plateaux. From the generalization of facts just given, the conclusion is, that the high continental elevation of the Antillean region extended northward in Hastern America, of which supporting data have been collected as far as Labrador. Submerged Plateau of the North Atlantic. If the analytical methods which have revealed the drowned valleys of the American coast be applied to the well-known North Atlantic plateau, similar valley-like phenomena will be discovered. While there are numerous soundings across the Atlantic, in the region of latitude 52°, the lines of soundings to the north are too far apart to everywhere afford detailed study of the submarine features; except that they show an extensive submerged plateau (from 7,000 to 9,000 feet) rising northward to the Iceland ridge, beyond which it again descends rapidly to depths of 12,000 feet, and west of Spitzbergen, 15,900 feet. The summit of the plateau, between Greenland and Norway, is submerged scarcely more than 1,200 feet. However, across the summit there are deeper channels, from the cols of which, valleys trend in opposite directions, like those amongst the West Indies or in the Straits of Florida. These cols are now submerged: that between Greenland and Iceland, to 1,974 feet; between Iceland and Faroe, 1,814 feet; between Faroe and Shetland, somewhat more than 3,000 feet ; and between Shetland and Norway, about 1,000 feet. The southern margin of this plateau (in the region of latitude 52°N.) is indented by embayments and amphitheatres, similar to those of ‘the border of the American plateau. From the comparatively numerous soundings upon the summit of the divide, and in the adjacent Arctic sea, the valleys from the cols just mentioned, and many others, can be traced to abyssmal depths. Thus, that between Greenland and Iceland descends rapidly from a depth of 2,000 feet to 6,642 feet, and may be followed to a depth of 9,000 feet. The valley in the opposite direction from the same col, extends northward, and receives the tributary from the Scoresby Sound (which is 1,800 feet deep far within the Greenland mass). In latitude 74°, there is a remarkable amphitheatre of 5,520 feet in depth; and just south-west of Spitz- bergen, a similar amphitheatre of 8,100 feet in depth is found where the plateau is submerged only a few hundred feet. Spitzbergen and © Norway are connected by a plateau which is generally depressed to less than 1,200 feet. From it valleys descend to the Greenland sea. Professor Spencer— Continental Elevation. OV The Baltic valley hugs the coast of Norway, and beyond that it extends to the same sea. From the col of the channel between Faroe and Shetland, at a depth of somewhat more than 3,000 feet, a great valley extends southward. North-west of Ireland, this valley reaches a depth of 9,980 feet, upon the north-westward side of which the plateau is characterized by: shallow banks; and it continues to a depth of 12,000 feet at the margin of the plateau. Tributary amphitheatres to this great valley may be seen westward of Ireland. One of these is 8,160 feet deep, where the platform has been depressed 5,040 feet; and two others have a depth of 10,500 feet, where the plateau is submerged only 4,000 feet. Further - southward, extending from the oceanic basin, a large embayment indents and extends far into the platform south-west of Ireland, having still a depth of 10,500 feet, where the shelf is covered by only about 2,500 feet of water. The Bay of Biscay is a remarkable embayment of great depth, with tributary amphitheatres like those just mentioned. The amphitheatres mentioned have no extraordinary widths. Their land equivalents are characterized by inconsiderable streams descending precipitously over steps from plateaux of great altitude. It is manifest, that Europe and Greenland form one continental mass, while the latter country is separated by a much deeper sea from the American continent. Accordingly, the search for these drowned valleys should be made by means of numerous soundings along lines parallel to the Iceland ridge, rather than off the coast of Ireland. From the fragmentary knowledge already acquired, it would be reasonable to expect the discovery of as complete systems of river-valleys as those found off the American coast and in the Antillean regions; indicating a late continental elevation of 12,000 feet or more. Continental Elevation a Cause for Glacial Climate. As has already been stated, the great continental elevation of Eastern America occurred during the early Pleistocene period, and was characterized by a stupendous amount of erosion, with the production of cafions and amphitheatres (at the heads of the valleys). Such an elevation of two miles or more, as measured by the depths of the valleys, must have produced a glacial climate in the more northern regions of America and of the North Atlantic. Thus we find a cause for the Glacial epoch; but many of the phenomena cannot be considered here. Whether the elevations of the North Atlantic and the American regions were absolutely simultaneous, or compensated each other with alternations, like the Antillean and Mexican undulations, is not known. Such alternations, with their diversions of the oceanic and atmospheric currents, together with the more recent partial submergence of the northern lands, would produce variations of the glacial phenomena, and would bring into close proximity those of high elevation and submergence, aud of warmer and colder climates. From as yet unpublished data, it appears that the late Pleistocene 388 Notices of Memoirs—Prof. O. C. Marsh on Hesperornis. depression of base-level in New England reached 2,700 feet at least. As there was a Mid-Pliocene (our separation of Pliocene and Pleistocene formations being largely arbitrary) elevation of unde- termined amount, and as there have been several minor oscillations of level of land and sea, there is great latitude in the application of the phenomena to the Glacial epoch not yet determined—only that great elevation of measurable amount did obtain in Pleisto- cene days. With alternations of elevation between the North Atlantic and American plateaux, the changes of currents would further modify the climatic conditions of the period, so that this paper only suggests one phase of physical changes—tending to produce the phenomena of the Glacial period. IN @ Per @ ser Sl @ ray aN aen VE @ ale Se _——-——>—_—_ I.—Tue Arrinities oF Hespzroryis.. By O. C. Marsa. N the autumn of 1870, I discovered in the Cretaceous of Western Kansas the remains of a very large swimming bird, which in many respects is the most interesting member of the class hitherto found, living or extinct. During the following year, other specimens were obtained in the same region, and one of them, a nearly perfect skeleton, I named Hesperornis regalis.2 In subsequent careful — researches, extending over several years, I secured various other specimens in fine preservation, from the same horizon and. the same general region, and thus was enabled to make a systematic investigation of the structure and affinities of the remarkable group of birds of which Hesperornis is the type. The results of this and other researches were brought together in 1880, in an illustrated’ monograph.® In the concluding chapter on Hesperornis, I discussed the affinities of this genus, based upon a careful study of all the known remaius. Especial attention was devoted to the skull and scapular arch, which showed struthious features, and these were duly weighed against the more apparent characters of the hind limbs, that strongly resembled those of modern diving birds, thus suggesting a near relationship to this group, of which Colymbus is a type. In summing up the case, J decided in favour of the ostrich features, and recorded this opinion as follows:— “The struthious characters seen in Hesperornis should probably be regarded as evidence of real affinity, and in this case Hesperornis would be essentially a carnivorous, swimming ostrich.” (‘ Odontor- nithes,” p. 114.) This conclusion, a result of nearly ten years’ exploration and study, based upon a large number of very perfect specimens and a comparison with many recent and extinct birds, did not meet with ? From the American Journal of Science, vol. ii, 1897. 2 Silliman’s Journal, vol. iii, p 46, January ; and p. 360, May, 1872. * « Qdontornithes: a Monograph on the Extinct Toothed Birds of North America.’’ 4to, 34 plates; Washington, 1840. Notices of Memoirs—Granites, &c., Lake Temiscaming, Canada. 39 general acceptance. Various authors who had not seen the original specimens, or made a special study of any allied forms, seem to have accepted without hesitation the striking adaptive characters of the posterior limbs as the key to real affinities, and likewise put this opinion on record. ‘The compilers of such knowledge followed suit, and before long the Ratite affinities of Hesperornis were seldom alluded to in scientific literature. Several times I was much tempted to set the matter right as far as possible by reminding the critics that they had overlooked important points in the argument, and that new evidence brought to light, although not conclusive, tended to support my original conclusion that Hesperornis was essentially a swimming ostrich, while its resemblance to modern diving birds was based upon adaptive characters. On reflection, however, I concluded that such a statement would doubtless lead to useless discussion, especially on the part of those who had no new facts to offer, and, having myself more important work on hand, I remained silent, leaving to future discoveries the final decision of the question at issue. It is an interesting fact that this decision is now on record. A quarter of a century after the discovery of Hesperornis, and a decade and a half after its biography was written in the “Odontornithes,” its true affinities, as recorded in that volume, are now confirmed beyond dispute. In the same region where the type-specimen was discovered, a remarkably perfect Mesperornis, with feathers in place, has been found, and these feathers correspond with the typical plumage of an ostrich.' IJ.—On tHe RELATIONS AND STRUCTURE OF CERTAIN GRANITES AND AssocraTeD ARkosEs oN Lake TemiscaminG, Canapa.” By A. EH. Bartow, M.A., and W. F. Ferrier, B.Sc., Geological Survey of Canada. \HE rocks to which the following facts relate outcrop on both the eastern and western shores of Lake Temiscaming iminediately north of the “Old Fort” Narrows on the upper Ottawa river, the deep channel of which forms the boundary-line between the Provinces of Ontario and Quebec. On the eastern side of the lake the granite forms a strip along the shore half a mile wide, extending from a point three-quarters of a mile north of “The Narrows” on which is situated the now abandoned Fort Temiscaming, a fur-trading post belonging to the Hudson Bay Company, to the steamboat wharf near the village of Baie des Peres. It also constitutes the rocky promontory known as Wine Point to the west of Baie des Péres, extending inland in a north-easterly direction for about one mile and a quarter. On the western side of the lake the first outcrop is noticed about half a mile west of ‘‘ The Narrows,” continuing along the shore for about four miles as far as 1 Williston, Kansas University Quarterly, vol. v, p. 53, July, 1896. 2 Abstract read before the British Association, Section C (Geology), Toronto, 1897. 40 Notices of Memoirs—Granites, §c., Lake Temiscaming, Canada. Paradis Point, and varying in breadth from half a mile to one mile. The whole area thus underlain by the granite is approximately about Six square miles. Macroscopically the fresh rock is a rather coarse, though very uniformly even-grained aggregate of felspar, quartz, and a dark- coloured mica, probably biotite. Felspar is by far the most abundant constituent, and the abundance of red oxide of iron disseminated through all the cracks and fissures of this mineral gives to the rock its beautiful deep flesh-red colour. The quartz is, as usual, allotriomorphic, but a decided tendency is noticed to segregate in more or less rounded areas or individuals which, especially on surfaces worn and polished as a result of glacial action, gives to the rock a porphyritic or pseudo-conglomeratic appearance ; a fact first made note of by Sir William Logan in 1844 on his manuscript map of this portion of the Ottawa river. The microscope shows the rock to be composed essentially of orthoclase, microcline, plagioclase (oligoclase?), quartz, and biotite almost completely altered to chlorite. ‘The microcline has evidently been derived from orthoclase as a result of pressure, and all the gradations of this change may be noted, from the ‘“ moire structure ” characteristic of the imperfectly or only partially developed mineral, to the fine and typical ‘cross-hatched structure” peculiar to this mineral. The felspar shows only incipient alteration to sericite, and scales and flakes of this mineral are developed especially abundantly in the central portion of the individuals, leaving a comparatively fresh periphery almost altogether free from such decomposition products. The arkose with which this granite is associated and surrounded is a beautiful pale or sea-green quartzite or grit, passing occasionally into a conglomerate, the pebbles of which are chiefly grey and red quartz with occasional intermixed fragments of a halleflinta-like rock. Under the microscope the finer-grained matrix appears to be almost wholly composed of pale yellowish-green sericite in the form of minute scales and flakes, although occasional individuals are macroscopically apparent. Most of this sericite has originated from the decomposition in siti of felspar originally present, and irregular portions or areas of the unaltered felspar may be occasionally detected. The line of junction between this granite and arkose shows a gradual and distinct passage outward or upward from the granite mass. The series of thin sections examined, as well as the hand- specimens themselves, show every stage in the process, which has been carefully studied. ° In the first place, as a result of dynamic action, the orthoclase is converted into microcline with the incipient development of sericite, which gradually increases in those specimens where the greatest perfection of the “cross-hatched” microcline structure is reached. In these the individuals of quartz and felspar have undergone rather extensive fracturing, but with little or no movement apart of the fragments. This breaking up of the original larger individuals is, Notices of Memoirs—Prof. T. R. Jones—Fossil Phyllopoda. 41 as usual, much more apparent in the quartz than in the felspar, and beautiful examples of ‘strain-shadows” may frequently be seen in those quartz areas which have not yielded altogether to the pressure. A further stage in the process is reached when the sericitization of the felspar has proceeded so far as to permit of the ‘‘ shoving apart”’ of the fragments by the various forces which have acted in bringing about the degradation of the whole rock mass. This gradual decom- position of the felspar and movement of the rock constituents can be perfectly traced in the series of thin sections examined until the rock cannot be distinguished from an ordinary arkose, while the arrangement on the large scale, and the more or less parallel alignment of rounded and waterworn quartzose fragments, amply testify to the final assortment and rearrangement of the disintegrated material as a result of ordinary sedimentation. The relations between this granite and arkose are of rather unusual scientific interest, showing, as they do, the Pre-Huronian existence of a basement or floor npon which these sediments were laid down, and which in this portion at least has escaped the movements to which the Laurentian gneisses have been subjected. The granite is also somewhat different, both in composition and appearance, from the granites and gneisses classified as Laurentian, and which are so frequently referred to as the Fundamental Gneiss or Basement Complex, although during recent years the assumption implied in these terms has been considerably weakened by the fact that the contact between such rocks and the associated clastics is, wherever examined, one of intrusion. On the other hand, the composition of the Huronian strata furnishes indubitable evidence of a pre-existing basement or floor essentially granitic in composition, while the abundance of red granite pebbles and fragments, which are so pre-eminently abundant in the breccia-conglomerate lying at the base of the Huronian system, are very similar in composition and appearance to the granite described above. This granite is, therefore, regarded by the authors as the only instance at present known in which the material composing the Huronian clastics can be clearly and directly traced, both macroscopically and microscopically, to the original source from which it has been derived. II.—Tuas Fosstn Poytiopopa oF THe Parmozorc Rocks. Thirteenth Report of the Committee, consisting of Professor T. Wiurssire (Chairman), Dr. H. Woopwaxp, and Professor T. Rupert Jones (Secretary). (Drawn up by Professor T. Rupert Jones.)? § I. 1889-1892. Anomalous Silurian Phyllopods (?) from Germany and America.—In the Sitz.-Ber. Gesell. naturf. Freunde zu Berlin, 1890, p. 28, Dr. A. Krause described a small fossil carapace of doubtful alliance, but possibly related to the Phyllopods, from the North-German gravel of Scandinavian Beyrichia-limestone (Upper Silurian). In the Zeitsch. Deutsch. Geol. Gesell., vol. xliv, 1892, p. 397, pl. xxii, figs. 19 a-c, Dr. A. Krause redescribed and figured this anomalous little fossil. 1 Read before the British Association, Section C (Geology), Toronto, 1897. 42 Notices of Memoirs— Its lateral moieties are not free, separate valves, but united by an antero-dorsal suture for a third of its length, and by an antero- ventral suture for half of its length, the posterior region remaining open at the edges. It also shows in front a round aperture, with a sulcus formed by the somewhat inverted edges below it. The test is nearly oval and compressed; thickest and subacute in front ; bearing a small, low, subcentral swelling. The surface has some reticulate ornament along the margins for the most part, succeeded by linear, radiating, and concentric sculpture towards the more convex area, which is finely punctate. It is 6mm. long, 4 mm. high, and 1:5 mm. thick. In §. A. Miller’s “North-American Geology and Paleontology,” 2nd edition, 1889, p. 549, fig. 1,009, an allied form is described and figured as Faberia anomala, n. sp. et gen., from the Hudson-River group, Obio (Lower Silurian). This has evidently some analogy to the foregoing Upper Silurian form. It has a compressed, ovoidal, smooth shell, consisting of two moieties. partially sutured above and below, and is rather smaller than the German specimen. § Il. 1885-1894. Cambrian Phyllopoda (?).—-Dr. G. F. Matthew, of St. John, New Brunswick, has discovered several very small organisms in the Cambrian rocks of North-Eastern America, some of which he regards, with doubt, as having been carapace-valves of Phyllopodous Crustaceans. He has described and figured them in the Transactions of the Royal Society of Canada. To this group of small subtriangular valve-like bodies, obliquely semicircular or semi-elliptical, with straight hinge-line and more or less definite umbo, belong (1) Lepiditta alata, M., Trans. Roy. Soc. Canada, vol. iii, 1885, sect. 4, p. 61, pl. vi, figs. 16, 16a; (2) L. curta, M., p. 62, pl. vi, fig. 17; (8) Lepidilla' anomala, M., p- 62, pl. vi, figs. 18, 18a, b,c; (4) Lepiditta sigillata, M.,. xi, 1894, sect. 4, p. 99, pl. xvii, fig. 1; (5) L. auriculata, M., p. 99, pl. xvii, figs. 2, 2a, b. Some of these were referred to by us in the Sixth Report (for 1888), p. 174. § III. 1889. Rhachura venosa, Scudder, 1878, Proc. Boston Soe. Nat. Hist., vol. xix, p. 296, pl. ix, figs. 3, 3a (referred to in our Report for 1888, p. 216). Dr. A. 8. Packard, having received from M. Gurley some imperfect specimens found in the Middle Coal- measures, Danville, Illinois, describes them as being parts of a carapace, probably a little over three inches long, and three caudal spines, also rather obscure (Proc. Boston Soc. Nat. Hist., vol. xxiv, 1889, pp. 212, 213). § 1V. 18938. Rhinocaris columbina.—Mr. J. M. Clarke has con- tributed a paper ‘“‘On the Structure of the Carapace in the Devonian Crustacean Rhinocaris, and the relation of the Genus to Mesothyra and the Phyllocarida,” with illustrative cuts, published in the American Naturalist, Sept. 1, 1893, pp. 793-801. The carapace- valves of Rhinocaris columbina (J. M. C., “ Paleont. New York,” 1 Dr. G. F. Matthew, in a letter of November 5, 1897, expresses a ‘‘ wish to withdraw Lepidilla, as not being a Crustacean; more perfect specimens seem to show a fan-like structure of internal tubes.” Professor T. Rupert Jones—Fossil Phyllopoda. 43 vol. vii, 1888, pp. Iviii and 195-7) are described from better speci- mens, which show it to be a bivalved (not univalved) form, and as having a narrow, median plate, of which there is evidence in Alesothyra, making a double dorsal suture. There is also a long, narrow, leaf-like rostrum inserted between the valves in front. The relationship of this form with Mesothyra and Tropidocaris is dwelt upon. ‘The author thinks that Dithyrocaris and Hmmelezoe have some affinity with it. Rhinocaris and Mesothyra are regarded as typical members of the family Rhinocaride. We may mention that Dr. Matthew regards his Ceratiocaris pusilla from the Silurian of New Brunswick (see Trans. Roy. Soc. Canada, vol. vi, 1888, sect. 4, p: 56, pl. iv, fig. 2; and our Seventh Report, for 1889, p. 64) as Rhinocaris. § V. 1895. Hmmelezoe Lindstroemi.—Since our Twelfth Report, presented to the British Association at Ipswich in 1895, the Swedish Phyllocarids mentioned in that Report as having been found by Dr. Gustav Lindstrém in the Upper Silurian beds at Lau, Gothland, have been duly described and figured in the GeoLtoeicaL MaGazine, Decade IV, Vol. II, No. 378, December, 1895, pp. 540, 541, PL XV, Figs. 2a—2d, as Hmmelezoe Lindstroemi, J. and W. he fish-remains (Cyathaspis) and other fossils associated with it are mentioned in detail by G. Lindstrém in the Bihang till K. Svensk. Vet.-Akad. Handal., vol. xxi, part 4, No. 8, 1895, pp. 11, 12. Mr. J. M. Clarke has suggested at p. 801 of his memoir, mentioned in § LV, that the oculate genus Hmmelezoe may have some relation- ship to the group to which Rhinoearis belongs. § VI. 1895. Pinnocaris Lapworthi.—This genus, represented by its only known species, P. Lapworthi, has been carefully examined by Woodward and Jones, and several specimens described, selected from a large number in Mrs. Robert Gray’s collection at Edinburgh. This memoir appeared in the GrotogrcaL Macazine, Decade LV, Vol. II, 1895, pp. 542-5, Pl. XV, Figs. 5-10. Excepting one specimen from the Upper Silurian of Kendal, Westmoreland, all the known specimens are trom the Lower Silurian of Girvan, Ayrshire, where Mrs. Gray has made a large collection. The peculiar “corded” dorsal margin of the valves may have reference to some longitudinal, narrow, intermediate ligament or plate as in Rhinocaris and Mesothyra. § VII. 1895. A new species of Ceratiocaris (C. reticosa, J. and W.), preserved in the Museum of the Geological Survey, was de- scribed in the GrotocicaL Macazrine, Decade IV, Vol. II, 1895, pp- 539, 540, Pl. XV, Figs. la, 1b. It is from the Silurian beds of Ludlow, Shropshire, and is allied to C. casstoides, from that locality. ‘Traces of a peculiar reticulate sculpture constitute its distinguishing feature. § VIII. 1895. Lingulocaris.—In the same number (378) of the GerotocicaL Magazine, 1895, at pp. 541, 542, a specimen Lingulo- caris lingulecomes, Salter, belonging to the Rev. G. C. H. Pollen, b.J., F.G.S., was figured and described. It came from Capel Arthog, North Wales, probably from the Ffestiniog or middle division of the 44 Notices of Memoirs—Prof. T. R. Jones—Fossil Phyllopoda. Lingula-flags. Hence we may add “ Lingulocaris” to ‘“ Hymenocaris” for that formation at p. 425 of our Twelfth Report (fifth line from the bottom). § IX. 1896. Devonian species of Ceratiocaris (?).— In the * Monograph of the Devonian Fauna of the South of England,” Paleont. Soc., vol. iii, part 1, 1896, the Rev. G. F. Whidborne describes and figures three obscure casts of Ceratiocaris, one C. (?) subquadrata, sp. nov., p. 7, pl. 1, fig. 5, from Hast Anstey ; another, Ceratiocaris (?) sp., p. 8, pl. 1, fig. 6, from Sloly; and the third, somewhat indistinct specimen, namely Ceratiocaris (?) sp., p. 8, pl. ii, fig. 12, from Croyde. § X. 1896. Hntomocaris and Ceratiocaris.— A collection of Ceratiocaris-like Crustaceans from the Lower Helderberg Formation (Upper Silurian), near Waubeka, Wisconsin, has afforded Mr. R. P. Whitfield, of the American Natural History Museum, New York, the opportunity of determining two new species of Ceratiocaris, and a new genus (nxtomocaris), allied to Ceratiocaris, but differing from it by the carapace-valves being “strongly curved in front and behind on the dorsal margin,” and by the posterior margin not being truncate, as in Ceratiocaris, but obtusely rounded. Lntomo- caris Telleri, Whitfield (p. 800), is figured in pl. xii, of full size, but slightly distorted by pressure. Including the four exposed body-segments and the trifid appendage, it is about 21 centimetres (about 8 inches) long; and the valves are about 154 centimetres long by about 64 high. Some indications of the swimming-feet attached to the body are visible where one valve has been partially broken away from the internal cast. Some mandibles, supposed to belong to this species, are shown in pl. xiv, figs. 1,2; and the caudal appendages in fig. 9. Ceratiocaris Monroet, Whitfield (p. 501, pl. xiii, figs. 1-5, and pl. xiv, figs. 3-8), is carefully described from one nearly perfect and an imperfect specimen, together with body-segments, caudal appendages, and some mandibles. The carapace-valves seem to have been about 74 centimetres long and 4 high. Ceratiocaris poduriformis, Whitfield (p. 502, pl. xiv, fig. 10), is represented by a small specimen of abdominal segments and caudal spines. § XI. 1896. Echinocaris Whidbornei, J. and W., noticed in our Seventh Report (for 1859), p. 63, has been redescribed and refigured by the Rev. G. F. Whidborne in the “Monogr. Devonian Fauna, S. England,” Pal. Soc., vol. iii, part 1, 1896, p. 6, pl. i, fig. 3. Within the last few months Ananda K. Coomary-Swamy, Esq., of Warplesdon, has fortunately obtained a very interesting specimen of this Hchinocaris from the Sloly mudstone, showing on the two counterparts of the little split slab, two individuals, each having the same characters as the specimen first described in the GnoLoatcaL Magazine, Decade III, Vol. VI, 1889, p. 385, Pl. XI, Fig. 1. Though rather narrowed by oblique pressure, the valves are equal in breadth to those of the first specimen. An additional feature of interest is seen in some body-segments, five in one individual and Reviews—Harker’s Petrology for Students. 45 three in the other. In each case, though the series of segments is not complete either at beginning or end, they are characteristically like those of Hchinocaris, the distal edges bearing tubercles, the equivalents of spinules. § XII. 1896. Caryocaris.—In the Journal of Geology, Chicago, vol. iv, 1896, p. 85, Dr. R. R. Gurley has described Caryocaris as the “lateral appendages” of the “polypary” of a Graptolite ! Caryocaris was referred to by us in the First and Seventh Reports (for 1883 and 1891), and was described in detail and figured in the ** Monogr. Brit. Paleeoz. Phyllocarida,” Pal. Soc. 1892, p. 89 et seq., pl. xiv, figs. 11-18. § XIII. 1897. A new locality in Nova Scotia has been deter- mined by Sir William Dawson for Estheria Dawsoni, namely, Kast Branch, East River, Pictou County, Lower Carboniferous. Several casts and impressions of small valves, not more than two millimetres long, occur on the bed-planes of a dark-red Lower Carboniferous shale. Former occurrences of this species were noticed in our Report (Hleventh) for 1894. I5y) Ja W/ JE Jah WY SE Perrotoegy FoR Stupents: An InrRopucTION TO THE SruDY or Rocks UNDER THE Mrcroscopr. By Atrrep Harker, M.A., F.G.S. Second edition, revised. 3834 pp., 75 figs. (Cam- bridge : Messrs. C. J. Clay & Sons, 1897. Price 7s. 6d.) HE appearance within two years of a second edition of so excellent a textbook as Harker’s “‘ Petrology for Students” is not a subject for surprise. In this revised edition the author states that he has endeavoured to profit by the criticisms of reviewers and private friends. The slight alteration, however, which the book has undergone shows how little cause for adverse criticism there was in the first edition. In general plan and scope the book remains precisely the same. Only about thirty pages have been added, and these are mainly due to the introduction of descriptions of American examples among the igneous rocks, one result of which is, that the reader makes the acquaintance of a number of those new names (Absarokite, Banakite, Carmeloite, Shonkinite, etc.) to the invention of which American geologists have of late been perhaps a little too prone. The method of classification of the igneous rocks remains practically the same, but Brogger’s name “hypabyssal”’ is sub- stituted for “intrusive.” As the author remarks, “ petrology has not yet arrived at any philosophical classification,” and certainly the attempt to pigeonhole the igneous rocks, both basic and acid, into the three groups, plutonic, hypabyssal, and volcanic, involves inconsistencies which are evident in the text. Thus three chapters intervene between the descriptions of such similar rocks as the pitchstones of Arran and the ‘pitchstones” (or, as the author prefers to call them, the Permian rhyolites) of Meissen; while the 46 Reports and Proceedings— Geological Society of London. treatment of the Derbyshire ‘“ toadstones” rather leaves the im- pression that they would have been described in connection with the Shropshire “diabases” but for the fact that “Mr. Arnold Bemrose regards them as contemporaneous lavas.” That there should be any difficulty in naming a rock before its mode of occurrence, either as an intrusive mass or as a lava-flow, has been determined, may present no terrors to the field-geologist ; but to the Museum-Curator it is hardly less appalling than the idea that before giving a rock a name it is necessary to determine its geological age. The author, it is true, is faithful to the British School in rejecting any distinction between rocks drawn from geological age; but the simplification in classification which should follow the removal of this incubus is partly discounted in this, as in many other English textbooks, by the fact that the hypabyssal groups are to a large extent recruited from rocks which are so mildly intrusive as to be included by Continental writers in their paleovolcanie groups (Hrgussgesteine). The book has been brought up to date by references to recent work, and still remains, what it was recognized to be on its first appearance, one of the most trustworthy guides for the student who wishes to take up the microscopic study of rocks. Ga aie aS ah SOS) /NINMD)) d354O\Caz pap Dslsy GrS- GerotocicaL Socrery oF Lonpon. I.—November 17, 1897.—Dr. Henry Hicks, F.R.S., President, in the Chair. The following communications were read :— 1. “The Geology of Rotuma.” By J. Stanley Gardiner, Esq., B.A. (Communicated by J. EK. Marr, Hsq., M.A., F.R.S.) The author describes the relationship of the island of Rotuma (situated in lat. 12° 380’ S., long. 177° 1’ E.) to the adjoining isles. It is almost separated into two parts, which are united by a narrow neck of sand. The interior is composed of volcanoes, which have emitted lavas and fragmental rocks. Around the volcanic rocks are stratified deposits composed of sea-sand with volcanic fragments. These are partly denuded, and are mantled round by coral-reef and beach sand-flats. A remarkable cavern in the lava of Sol Mapii, with lava-stalactites, is described; there is a similar cavern in Au Huf Hof. An account of the prevalent meteorological conditions is also given. In an Appendix by Mr. H. Woods, M.A., some of the rocks are described. They consist of olivine-dolerites and basalts and asso- ciated fragmental rocks. 2. “ A Geological Survey of the Witwatersrand and other Districts in the Southern Transvaal.” By Frederick H. Hatch, Ph.D., F.G.S. After giving an account of the physical characters of the area, the author proceeds to describe the various rocks referred to (1) The Karoo System, (2) The Cape System, (3) The Primary or Archvan System. Reports and Proceedings—Geological Society of London. 47 The Archean rocks protrude in a few places through the sedi- mentary beds, which form the greater part of the area, and consist of an igneous complex of rocks of varied composition. The Cape System is capable of division into five distinct series :— Magaliesbere and Gatsrand series; alternating quartzites, shales, and ( to) 5 to) q > b) Ween | lava-flows. 16,000 to 20,000 feet. Beds 4 Dolomite and cherts, thickly bedded. 6,000 to 8,000 feet. "| Black Reef; a bed of quartzite and conglomerate, 20 to 50 feet, and Klipriversberg amygdaloid; a basic volcanic rock, 5,000 to 6,000 feet. Witwatersrand Beds; sandstones and conglomerate (in part auriferous). LoweEr 11,000 to 15,000 feet. Bzps. ) Hospital Hill series; quartzites and ferruginous shales. 8,000 to 10,000 feet. A full description of each of the series, and the associated volcanic and igneous rocks, is given in the paper. The Karoo formation is represented by the Coal-measures of Vereeniging and the district south of Heidelberg, and by the measures of other coal-areas. They have furnished plants which Mr. Seward refers to in a note as being of Permo-Carboniferous age. The age of the Cape System is doubtful. The Upper beds rest unconformably on the Lower ones, and if the latter be of Devonian age, aS has been inferred, the former may represent the Lower Carboniferous rocks. In conclusion the author makes some observations upon the geotectonic relations of the area. 3. “Observations on the Genus Aelisina, De Koninck, with Descriptions of British Species, and of some other Carboniferous Gastropoda.” By Miss J. Donald, of Carlisle. (Communicated by J. G. Goodchild, Esq., F.G.S.) The author makes some preliminary observations on the genus Aclisina, and considers it advisable to regard A. pulchra as the type of the genus, while the so-called A. striatula must be placed among the Murchisonig, and A. nana is placed in a new genus. The author gives a diagnosis of Aelisina, De Kon., belonging to the family Turritellide, and describes the British species, twelve of which are new, including two new forms placed in a subgenus. Of the family Murchisonide, and in the section Aclisoides of the genus Murchisonia, the form of A. striatula, De Kon., and a variety are described; and a diagnosis of the new genus, in which A. nana of De Koninck is placed, is given, followed by a description of the species. TI.—December 1, 1897.—-Dr. Henry Hicks, F.R.S., President, in the Chair. The following communications were read :— 1. “A Revindication of the Llanberis Unconformity.” By the Rev. J. F. Blake, M.A., F.G.S. In a paper published in the Quarterly Journal of the Society for 1895, the author of the present paper maintained that certain conglomerates and associated rocks occurring for some distance north-east aud south-west of Llanberis, which had hitherto been 48 DPeaalRraacons. considered to lie below the workable slates of the Cambrian rocks of that area, were in reality unconformable deposits of later date than those slates. In 1894 (Quart. Journ. Geol. Soc., vol. u, p. 578), Professor Bonney and Miss C. A. Raisin maintained that in no case which they had examined could any valid evidence be found in favour of the alleged unconformity, and that in one (on the north-east side of Llyn Padarn) which they supposed to afford the most satisfactory proof of it, the facts were wholly opposed to the notion. The present paper is a reply to these authors, in which ast objections, founded on general considerations, on field observations, and on microscopic examination of rock-specimens, are discussed, and the author gives the results of further observations on the rocks of the district. 'The Moel Tryfaen sections and those on each side of Llyn Padarn in the Llanberis district are considered, and he maintains that the post-Llanberis (using this term in the sense of being after the deposition of the main workable slates) age of the conglomerates which are under discussion is established; though the more he considers the correlation of these conglomerates with the Bronllwyd Grits the less he likes it, and as far as the strati- graphy is concerned, they may be much newer—their age is at present an open question; but of their unconformable position he has no doubt. 2. “The Geology of Lambay Island, Co. Dublin.” By Messrs. C. I. Gardiner, M.A., F.G.S., and §. H. Reynolds, M.A., F.G.S. The authors, who have previously described the neighbouring district of Portraine (Quart. Journ. Geol. Soc., Dec. 1897), under- took an examination of this island, with the intention of comparing the rocks with those of Portraine, and of investigating the nature of the rock familiar to geologists under the name of ‘“ Lambay porphyry.” The sedimentary rocks are similar to some of those of Portraine, and are of Middle or Upper Bala age. Associated with them are pyroclastic rocks and andesitic lava-flows, some of the lavas having flowed beneath the sea. The sediments and volcanic rocks were exposed to denudation, and a conglomerate composed of their fragments was accumulated round the volcano. The “ Lambay porphyry,” which has been determined as a diabase-porphyry by Dr. von Lasaulx, is partly intrusive in the other rocks, but has in places come to the surface as a lava-flow. Petrographical descriptions of the various rocks are given by the authors. IMEIES Oss En IE) /A IN fasHO) US ies PaaS New GeotocicaL Survey Mars. — Since our notice in the GeotocicaAL Magazine for 1897, p. 192, several other of the Sheets of the General Map of England and Wales (scale one-inch to four miles) have been issued, printed in colours and priced 2s. 6d. each. ‘These include Sheets 2, Northumberland, etc.; 8, Index of Colours; 4, Isle of Man; 7, North-West Wales; 10, Parts of South Wales and North Devon; and 18, Cornwall and the Scilly Isles with part of Devon. GEOL. Mac. 1808. Decade IV, Vol. V, Pl. IL Antlers of the great Red-Deer, Cervus elaphus, Linn. Alport, Youlgreave, Bakewell, Derbyshire. [Described in Phil. Tyans., 1785, vol. Ixxv, p. 353-] Reduced to 7; natural size. THE GEOLOGICAL MAGAZINE NEW SERIES. DECADE IV. VOL. V. No. II.—FEBRUARY, 1898. ORIGINAL ARTICLES. L.—Nors on roe Antirrs or A Rep-Derr (Cervus nnapuus, Linn.) From ALporT, YOULGREAVE, NEAR Bakrwett, DerpysHire —now in the British Museum (Natural History), Cromwell: Road, London. | By Hexry Woopwarp, LL.D., F.R.S., V.P.G.S., ete. (PLATE II.) i 1891, Frank §. Goodwin, Hsq., of Bakewell, Derbyshire, presented to the British Museum (Natural History) a pair of antlers of red-deer, with fragments of the calvarium attached, which had been obtained, with other cervine remains, from a tufaceous: deposit of comparatively modern date near Bakewell, Derbyshire. Owing to the loss of all animal matter the antlers were in a very: friable condition and fell in pieces on being handled, although at some distant time they had been repaired partially with long strips of calico. Two causes rendered them of interest: firstly, they were of unusually large size, resembling the great American Wapiti (Cervus: Canadensis) in stoutness and length of beam; secondly, they proved to have been described in a letter from the Rev. Robert Barber, B.D.,: to John Jebb, Esq., M.D., F.R.S., which was published in the Phil, Trans. Royal Society for 1785 (vol. Ixxv, p. 353). Notwithstanding their almost hopeless state of dilapidation, they attracted the attention of Sir Edmund Giles Loder, Bart., and Mr. J. G. Millais (the latter of whom examined and made drawings of them about a year ago). An attempt was made to bring the broken antlers together again ; and after much time and labour expended by Mr. C. Barlow, the Formatore, they have at length been successfully rehabilitated, and are now exhibited on the top of pier-case No. 16, in the Geological Gallery devoted to fossil Mam- malia, where they form, from their size and whiteness, one of the most striking objects in the series of cervine remains. The following is the account printed in the Phil. Trans. R.S. for 1785 (vol. Ixxv, p. 853), read April 14th, 1785 :— DECADE IV.—VYOL. V.—NO. II. 4 00 Note on Antlers of Red-Deer from Bakewell, Derbyshire. “About five years ago, some men working in a quarry of that kind of stone which in this part of the country we call ‘tuft’ [tufa],* at about five or six feet below the surface, in a very solid part of the rock, met with several fragments of the horns [antlers] and bones of one or different animals. « Amongst the rest, out of a large piece of the rock which they got entire, there appeared the tips of three or four horns [antlers] pro- jecting a few inches from it, and the scapula of some animal adhering to the outside of it. A friend of mine, to whom the quarry belongs, sent the piece of the rock to me, in the state they got it, in which I let it remain for some time. “But suspecting that they might be tips of the horns [antlers] of some head enclosed in the lump, I determined to gratify my curiosity by clearing away the stone from the horns [antlers]. On doing which, I found that the lump contained a very large stag’s head, with two antlers upon each horn, in very perfect preservation, inclosed in it. “Though the horns [antlers] are so much larger than those of any stag I have ever seen, yet, from the sutures in the skull appearing very distinct in it, one would suppose that it was not the head of a very old animal. “T have one of the horns nearly entire, and the greatest part of the other, but so broken in the getting out of the rock, that one part will not join to the other, as the parts of the other horn [antler] do. “The horns [antlers] are of that species which park-keepers in this part of the country call ‘throstle-nest horns,’ from the peculiar formation of the upper part of them, which is branched out into a number of short [tines or] antlers which form a hollow about large enough to contain a thrush’s nest. ‘“‘T send you the dimensions of the different parts of them, com- pared with the horns [antlers] of the same species of a large stag which have probably hung in the place from whence I procured them, two or three or perhaps more centuries; and with another pair of horns [antlers] of a different kind which are terminated by one single pointed antler and which were the horns [antlers] of a seven-year-old stag [Cervus elaphus |. ‘‘The river Larkell runs down the valley, and part of it falls into the quarry where these horns [antlers] were found, the water of which has not the property of incrusting any bodies it passes through. “Jt is therefore probable that the animal to which these horns [antlers] belonged was washed into the place where they were found, at the time of some of those convulsions which contributed to raise this part of the Island out of the sea. « Besides this complete head, I have several pieces of horns, bones (particularly the scapula I mentioned above), and several vertebree of the back found in the same quarry; some, if not all, of them probably belonging to the animal whose head is in my possession. 1 Tuft (¢fa) is a stone formed by the (calcareous) deposit left by water passing through beds of sticks, roots, vegetables, etc., of which there is a large stratum at Matlock Bath, in this county. —_—- J. E. Marr and R. H. Adie—The Lakes of Snowdon. 51 Dimensions oF THE Horns [ANTLERS] FouND at ALport. ft. ins. Circumference at their insertion into the corona .., ats ae Oe a. Length of the lowest antler [brow-tine | 000 Has coo LD 6. Length of the second antler [bez-tine | : B05 bats 114 c. Length of the third antler [trez-tine] ... De wes ae ie Le Length of horn antler [in the beam] ... ee 600 coo | ia) aes Dimensions or Lance Parr or ‘ THrostie-nest Horns’ (ORDINARY Rep-DrEr ANTLERS). ft. ins. Circumference at their insertion into the corona ... as 500 7 a. Length of the lowest antler {brow-tine] oa bine Pa O b. Length of the second antler {bez-tine] ... 104 c. Length of the third antler [trez-tine] ... wee 00 bb 114 Length of horn antler [in the beam] ... a3 300 eel! |e VOY Dimensions oF THE Horns or Aa Stag Seven YEARS Op. ft. ins. Circumference at their insertion into the corona ... BB 200 Ox a. Length of the lowest antler [brow-tine ] tae uae oo 9 b. length of the second antler [bez-tine]... es “oe tee 10 c. Length of the third antler [trez-tine] ... Bhs Le pn 10 Length of horn antler [in the beam] ... ae 00C coo | BF «6 Youlgreave, January 25rd, 1785.” P.S.—The following measurements have been taken since the antlers have been repaired and mounted in the Gallery.! MzasuREMENT OF ANTLERS OF Cervus elaphus FROM ALPORT, YOULGREAVE. ft. ins Width at the ‘‘nests”’ ... 200 be 500 Eco aaa) Length of right antler ... 260 be 000 Bee) eg AO Pe aslett 99 066 é0 bc Bee eon 8 5) pp RON SUI) | oo baa GbG. Hse SHEE G00 11 Maeda 55 so oot oo 600 ely Munle vt) WN STU he ase cde hy ou, TSN TAG ee ERT SO Girth of pedicle 74 », above the burr oF Me », Ist tine oe ae cod ce 9f um pp) ean pe 500 900 6oc ee boc 65 a PuKords, a4 on Sc ask S06 ie 65 IJ.—Tue Lakes or Snowpon. By J. E. Marr, M.A., F.R.S., and R. H. Aprz, M.A., F.C.S., Lecturers of St. John’s College, Cambridge. M\HE waterways of Wales owe their directions to a complex series of events which it is not our province to discuss in this place, but the minor features of Snowdonia are largely determined by planes of weakness which were produced in the rocks of the region during the occurrence of the marked earth-movements at the close of Silurian and Carboniferous times. The Post-Silurian earth-move- ments gave rise to planes of weakness running in a general north- east and south-west direction, and in a direction at right angles 1 See also ‘‘ British Deer and their Horns,”’ by J. G. Millais, p. 96, fig. 2, and p- 105. (Roy. 4to; Sotheran & Co., 1897.) 52 J. E. Marr and R. H. Adie—The Lakes of Snowdon. to this. Amongst other features parts of the coastlines of Anglesey are determined by these planes of weakness. The Post-Carboniferous planes run approximately north-and-south and east-and-west. The Glaslyn below Beddgelert runs generally along a north-and-south plane and the Capel Curig Valley along one extending in an east-and- west direction. The Snowdon mass, with its northern prolongation forming the Moel Hilio range, is of a rectangular shape. It is about ten miles long, and has an average width of about four miles. The ridge runs in a general north-west and south-east direction, whilst the ends are at right angles to this, for the Snowdon mass is bordered by depressions coinciding with planes of weakness produced during the Post-Silurian period of earth-movement. On the north-east side the mass is bounded by the upper portion of the Seiont Valley, containing the two lakes of Llanberis; on the south-west side by the upper part of the Gwrfai Valley, holding the lakes of Cwellyn and Llyn-y-gader, and the head of Nant Colwyn; the south-eastern boundary is formed by the Vale of Gwynant, with Llyn Gwynant and Llyn-y-ddinas; and on the north-west is a portion of the Seiont, east of Carnarvon, which has worn its bed along the soft Arenig shales. Of ridges determined by the Post-Silurian changes, the pre- vailing one is that which runs north-west and south-east from Moel Hilio, through Moel Goch and Moel Cynghorion, over the summit — of Snowdon, and is continued to the south-west as the buttress of Lliwedd. At right angles to this is the ridge of Crib-y-ddysgl, and also the ridge running from Snowdon on the Beddgelert side known as Llechog, part of which, however, runs parallel 1 to the north-west and south-east system, as does also the ridge which culminates in the peak of Yr Aran. Of the ridges determined by the north-and- south and the east-and-west planes of weakness, the most important are that of Crib Goch, which runs east and west, and that extending between Snowdon and Y Geuallt, which is at right angles to this. Bounded by these ridges and others having the same general directions, lie the six beautiful ecwms of Snowdon, four of which contain one or more lakelets. We have laid stress upon the planes of weakness, because they contribute some information concerning the origin of the lakelets. The south-eastern and south-western shores of Liyn Llydaw are defined by two Post-Silurian planes of weakness. In the cwm on the west side of Snowdon, the three upper tarns, Llyn Glas, Llyn Coch, and Llyn-y-nadroedd, occur on a north-east and south-west line; the stream from the central one, Llyn Coch, runs at first along a north-west and south-east line, and this, if continued, runs along the long axis of Llyn Ffynnon-y-gwas. The principal precipices of Snowdon occur on the north-east side, and the same feature is seen in the case of the Glyder range; and in the Lake District the east side of the Helvellyn and High Street ranges is the precipitous one. Minor examples may readily be | called to mind showing a precipitous eastern slope and gentle western one, and the cases are too frequent to be merely accidental. It is possibly due to the rainfall from the south-west, and the south- J. EH. Marr and R. H. Adie—The Lakes of Snowdon. 58 westerly aspect of the slopes causing much vegetation to grow on the south-west faces of the hills and giving rise to peat-mosses, thereby allowing the waters to discharge gently instead of running off at once. In connection with this, we may notice that the streams on the north-east side of the Snowdon range are gradually cutting their way back into the hills, thus shifting the watershed to the south-west of its general trend where these notches are formed. This is specially well seen in the case of the passes of Maes Cwm and Cwm Brwynog between Snowdon and Moel Hilio. The literature dealing with the Snowdonian Lakes is not ex- tensive. No doubt all geologists have read the masterly account of “The Old Glaciers of Switzerland and North Wales,” by Professor Ramsay, which originally appeared in the series of “ Peaks, Passes, and Glaciers,” and was afterwards published separately in 1860. Recently Mr. W. W. Watts contributed “ Notes on some Tarns near Snowdon,” which will be found in the Report of the British Association for 1895 (p.683) and also in this Magazine (Dec. IV, 1895, Vol. I, p. 565). During last Easter Vacation we paid some attention to the lakes and tarns of Snowdon, and believe that our observations may be of some use as a small contribution to the subject of the origin of lakes. In the first place we will deal with the lakes of the larger valleys of the Seiont, Gwrfai, and Gwynant, and then notice the lakes and lakelets which lie embosomed in the upland hollows of Snowdon. The Seiont, rising at the Pass of Llanberis, flows in a north- westerly direction through the two lakes of Llanberis, Llyn Peris and Llyn Padarn. These lakes were once one, and are now separated by the alluvial strip near Dolbadarn Castle. This strip is part of the delta brought down by the stream which descends from the heights of Snowdon and Moel Hilio, and it is of interest to notice that at one time a considerable bay must have extended up the valley occupied by this stream, for alluvium extends some way towards the waterfall Ceunant Mawr. In Llyn Peris there is a bay on the south-west side of the lake, which is continued landward as a valley of some importance, down which a stream of minute proportions runs, and consequently the sediment which it has borne down has been insufficient to fill up the bay. Several similar bays at one time marked the south-west shores of Llyn Padarn, but as the lakes of Llanberis are now used as receptacles for slate-rubbish, the primary features of their shore-lines are almost obliterated. Llyn Peris once extended much further up the valley, as shown by the strip of alluvium extending to Gwastadnant. The present exit of the river from Llyn Padarn is between two rocky masses, but there is a considerable width of ground, on which the bridge at Cwm-y-glo is built, which shows no rock in siti, though it probably exists at no great depth beneath the surface. A depression occupied by alluvium leaves the lake on its western side, about a quarter of a mile south of the present exit, and curving round a rocky knoll joins the present stream opposite the village of Cwm-y-glo. It is somewhat over 100 yards wide in its narrowest part (where it 04. J. BE. Marr and R. H. Adie—The Lakes of Snowdon. leaves the lake at the north end of the railway tunnel), and the alluvium is just above lake-level. There is no stream of any im- portance in this valley, and it is difficult to account for its existence unless we suppose that the main river ran through it, and that it became filled with drift, causing the formation of the lake, which drained over what was formerly a low col, situated at the present exit. Near the point where this old valley joins the present one, are several large pools in the present valley surrounded by alluvium. They are probably ‘kettle-holes” in the drift. The floor of the Seiont Valley is occupied by drift all the way from the lake to the sea, so that it is quite possible that the floor of the lake may be below sea-level and yet that the lake may not be in a rock-basin. We now proceed to consider the two lakes of the Vale of Gwynant. Hach is about three-quarters of a mile in length, and has its longer axis running in the direction of the valley. Llyn Gwynant is the higher of the two, and the bottom of the valley is occupied by dritt between its foot and the head of Llyn-y-ddinas. At the head of the latter lake, the river has partly cut its valley through this drift, but without reaching the rock. The exit from this lake is apparently over rock, though no actual rock is seen in the stream at the outlet, but the width of the area devoid of rock is here very small. A bold rocky eminence lies between the foot of the lake and the road; the road is carried along a drift-filled depression west of the present exit for a short distance, and to the north of this the drift-filled depression is seen north of the road, and joins the lake a few hundred yards above the exit. This depression is about thirty yards wide in its narrowest part. To the south-west it joins the drift- covered bottom of the valley, and this valley-bottom is covered with drift to some distance below Beddgelert. It may be noted that Beddgelert stands on an alluvial flat which was once an old lake, and a barrier of rock runs across the stream at the entrance to the Pass of Aberglaslyn, but a drift-filled depression is seen to the west of this, which joins the main valley a short way down the pass. The lakes in the Gwrfai Valley present points of some interest. Llyn Cwellyn is 464 feet above sea-level. An alluvial flat runs for half a mile from the foot of the lake, and no doubt marks a former portion of the lake filled up by the sediment brought down by the small streams from Moel Hilio and Mynydd Mawr. The water then runs over rock forming the cascade at Nant Mill, and the head of this cascade is only about five feet below the level of Cwellyn. At this point a barrier of rock extends right across the valley in such a way as to forbid the existence of any drift-filled depression, which could account for the lake. We lay special stress upon this point, for it might be urged that a possibie drift-filled channel could be indicated in the case of all lakes, owing to the large extent of ground where live rock is not seen as compared with that which shows the rocks in sit. One of us has had considerable experience in the examination of the exits of lakes, and has found so many (like Llyn Peris and Llyn-y-ddinas) where there is only one possible exit, that he felt sure that if rock-basins exist with any frequency in J. BE. Marr and Rk. H. Adie—The Lakes of Snowdon. +595) Britain, there must be some where proof is obtainable that there is no possible drift-filled exit. Cwellyn illustrates this: there is no possible exit at the foot, and if this lake were backed by high hills towards the head, the existence of a rock-basin could be proved here ; but, as we shall now proceed to point out, the physiographical features at the head of the lake are compatible with the existence of a drift- filled depression in this direction ; and, indeed, some of the phenomena exhibited above the head of Cwellyn are extremely difficult to explain, unless such a depression exists there. _ An alluvial flat extends above Cwellyn for a quarter of a mile up the Gwrfai. This river runs over solid rock at Rhyd-ddu between Owellyn and Llyn-y-gader, but a drift-filled depression is traceable from the head of the alluvial flat, firstly up the main stream, then up a tributary joining it a few yards south-east of Cwellyn Slate Quarry ; it crosses a low watershed at a height of 740 feet (i.e., nearly 300 feet above the surface of Cwellyn, and nearly 150 feet higher than that of Llyn-y-gader), just east of Ffridd Slate Quarry, after which it follows another small stream and joins Llyn-y-gader close to the prominent crag, which stands out of the allavium on the east side of the lake. This is the only possible exit in this direction, and its resemblance to a drift-filled gorge is very striking. The depth of Cwellyn is, so far as we are aware, not known; but assuming it is nearly 50 feet deep, the gorge, which is about 80 yards wide at the narrowest part, would require to be 3850 feet deep at this point, in which case it would be comparable with some of the Alpine gorges. Such gorges might well be cut by the water issuing from a glacier, and highly charged with sediment, and the nature of the ground is favourable for the formation of one at this point, for it is occupied by a well-jointed basic intrusive rock. Furthermore, the rock comes to the surface here so extensively, that there is no approach to any similar drift-filled depression; in fact, where the depression crosses the col, it is a conspicuous feature owing to the rocky ridge above and below it, and it is difficult to understand why this con- tinuous tract of drift-covered ground occurs here, except on the supposition that a valley lies below. If the possibility of the existence of the gorge be admitted, there is no difficulty connected with the introduction of the drift, for the locality is just beneath the ereat cwm on the west side of Snowdon, which must have been the gathering-ground of a large glacier, and also lies below the drift- covered tract on the upland plateau on which Maen Bras stands. There is another remarkable feature which requires explanation, but which is readily understood if it be supposed that a drift-filled valley exists here. ‘T’o the south-east of Llyn-y-gader is a peaty moor, which slopes gently to the watershed separating the Gwrfai from the Colwyn. Viewed from the detached mass known as Pitt’s Head, the watershed appears as a level line, and is apparently composed of an alluvial deposit. It strikingly resembles one which one of us has previously described at the head of Wet Sleddale in Westmoreland (Got. Maa., Dec. 1V, Vol. I, p. 539), and as in the case of the Wet Sleddale watershed, may be accounted tor on the supposition that 56 J. E. Marr and R. H. Adie—The Lakes of Snowdon. a valley was here stopped up by ice, and partly converted into a lake, which became largely silted up with sublacustrine detritus. The bed of the Colwyn runs over drift until within a short distance of Beddgelert. It will be seen, therefore, that a continuous line of drift-covered tract can be traced from Nant Mill, past Cwellyn and Llyn-y-gader, for a distance of about four miles. If the drainage has been reversed between the present head of the Gwrfai and Nant Mill, the curious course of the stream from Llyn-y-dywarchen will be accounted for. This stream runs a little east of south into Llyn- y-gader, whilst the Gwrfai issues from that lake in a general. northerly direction, whereas if the waters of the Cwellyn and Llyn- y-gader depression originally drained southwards, the Llyn-y- dywarchen stream would then have proved a normal tributary to the river once occupying that depression. We may now pass on to the consideration of the upland tarns and lakes. The four tarns on the west side of Snowdon may be dismissed in a few words. The late Professor Ramsay speaks of them as follows: ‘The lake called Llyn Ffynnon-y-gwas is possibly dammed up by moraine matter”; and again, “a minor moraine encircles Llyn-y-nadroedd on the north and east, and another beautiful small one made of angular blocks and stones, now covered with vegetation, bounds Llyn-goch on the west and south-west, while a third dams up Llyn-glas.” None of these lakes, then, can be claimed as resting in a rock-basin, nor can the drift-stopped tarn below Moel Hilio (Llyn Cwm Dwythwch) be asserted to rest in a basin of that nature. The lakes lying to the north-west of the main Snowdon ridge merit a fuller description. Below the precipice Clogwyn du’r Arddu, lies the little Llyn du’r Arddu at a height of 1,900 feet above the sea. The extensive moraine which blocks it up, and extends far down Cwm Brwynog in a series of concentric semi- circles, is admirably described by Professor Ramsay. The exit to the west is between the great drift dam and solid rock ; the latter is well rounded with striz running parallel to the stream, and the rough sides of the roches moutonnées face westward. On them rest sub- angular perched blocks, whilst the innermost crescent of the drift- dam consists of angular blocks, as though some at least of this material was rather of the nature of snow-slope detritus than true moraine. It is quite clear that the course of the stream before the lake was formed cannot have been as it is now, otherwise no lake would have been produced ; it must have run in a more northerly direction, but this former valley is now completely buried beneath gigantic moraine-mounds for a long distance. We call attention to this, as we shall have occasion to recur to the point when describing the exit of Llyn Llydaw. The water of Llyn du’r Arddu is of a deep indigo tint, a colour not represented in Forel’s scale of lake-colours. It is popularly asserted that the colour is due to the presence of copper in the water ; but we are not aware that any analysis has been hitherto made to test this. Old copper-mines exist close to the lake, but as one of us has been unable to find any trace of copper in the lake-water, it would J. EH. Marr and R. H. Adie—The Lakes of Snowdon. 57 seem that the colouring is not caused by the presence of this sub- stance. The same may be said concerning the waters of Glaslyn and Llyn Llydaw, which have also yielded no trace of copper. Cwm-glas is the next hollow which contains lakelets, and these have been specially noticed by Mr. Watts. He states that there can be little doubt that the upper lakelet “is a portion of a bending valley dammed at both ends by scree- and stream-débris, and thus compelled to find an escape over the rocky side”; and that in the rainy season the lakelet finds ‘‘a second outlet over the long, low col to the east, so that in this state it has the two outlets depicted in the six-inch map.” We here find a missing link in the series of lakes leading up to those whose outlet is permanently over solid rock. One of us has described Hard Tarn on Helvellyn, a lakelet which strikingly recalls this tiny lakelet on Snowdon, being, like it, situated on a shelf formed by a dip slope between two escarpments (Quart. Journ. Geol. Soc., vol. lili, p. 13). In the Helvellyn pond, the normal outlet is over drift, whilst the wet-weather outlet is over solid rock; in the Cwm-glas pool, the normal outlet is over solid rock, and the wet-weather one over drift, for the drift has accumu- lated to a greater extent than that at the end of Hard Tarn. The next stage in the Cwm-glas pool will be the complete stoppage of the eastern exit over the drift, when the pool will drain permanently and in all weathers over the solid rock. : The lower pool of Cwm-glas is stated by Mr. Watts to be “certainly confined in a rock-basin, as rock occurs at its actual outlet, and at every point where any former outlet might have been possible. The lake is, however, so shallow that its occurrence in a basin of rock is perhaps of little consequence.’ We had hoped to obtain soundings of this lake, but owing to the quantity of floating ice, were unable to do so, although as the bottom is everywhere visible, there is probably no spot where the depth reaches six feet. We could not satisfy ourselves that the pool occupied a true rock-basin. The stream issues from the lake with a bank of solid rock at each side, but the stream is some feet in width here, and its floor strewn with boulders, and a former ravine six or more feet in depth might readily be blocked by detritus at this point. We do not, however, believe that this is the case, for just east of the present exit a drift-filled depression is seen, which runs parallel to the existing stream, and joins it about 150 yards below the exit, at a level far below that of the lakelet. The col in this drift-filled depression is about 15 yards north of the exit, and there we found a width of about five yards across from obviously live rock on either side. It is true that large blocks of stone here extend right across, but they do not seem to be in siti, for the cleavage planes run in very different directions in the different blocks. It was easy to bury a walking-stick up to the handle at several points along this depression, and in other cases the stick was prevented from penetrating by coming in contact with obvious boulders which were movable. ‘his pool, like the upper one, is situated on a dip slope shelf between two escarpments, and the ice 58 J. E. Marr and R. H. Adie—The Lakes of Snowdon. has merely rounded off the edges of the escarpments without altering their general character. It has acted like sandpaper, and there is no indication of such erosion as would produce a rock-basin,—quite the reverse. ‘The same feature may be noticed in the case of Sprinkling Tarn on Scawfell. ; The last cwm which contains lakes is the magnificent one east of the summit of Snowdon. The lowest lake, Llyn Teyrn, is shallow, and the stream from it flows over drift for a long distance below the exit. Near this tarn, and close to the path, a glaciated rock shows intercrossing striz, one set running east and west and the other about 30° E. of N. and 30° W. of 8S. A better example of intercrossing is seen by the path bordering the shores of Llyn Llydaw, due west of the causeway. A roche moutonnée shows three sets of striations—one trending H. and W., another 8.W. and N.E., and the third 85° W. of N. and E. of 8. These directions point respectively to the top of Snowdon, the Lliwedd cliffs, and the cliffs immediately above the roche moutonnée, and were probably produced by glaciers coming from those directions at different times. We call attention to them to emphasize a difficulty which has often been felt if one assumes that glaciers can carve out rock-basins and yet are unable to obliterate the strie formed at other times. Mr. Kendall has, however, shown that the same mass of ice produces intercrossing strie; also, we are aware that glaciers, like rivers, must be under conditions more favourable for erosion at some times than at others ; the difficulty is, therefore, by no means insuperable to those who maintain the power of ice to form rock-basins, but still we think it is a difficulty. Mr. Watts writes :—‘‘Immense quantities of moraine material occur on the south-east side of Llydaw, but a careful examination of the map shows that only two possible outlets exist—that now used for the purpose; and a second which is occupied by bog resting on moraine, and gives rise to a small stream which is joined lower down hy the outlet of Llyn Teyrn. The moraine is, however, only a thin skin on the surface of the rock. The present outlet shows live rock forty or fifty feet below the level of the lake, and the second possible exit at a rather less distance below the same level. If the moraine were stripped off, there is little doubt that this lake . . . . would show a basin of rock which would hold water, unless it is very much shallower than is generally supposed to be the case.” It is very desirable that accurate soundings of this lake should be made; indeed, we wish someone would do for the lakes of North Wales what Dr. Mill has so admirably performed in the case of those of English Lakeland. Mr. Watts’ observations would permit the existence of a lake forty feet deep, which is not situated in a rock-basin, and our observations lead us to believe that a very much greater depth of water may be here held up by drift. A great moraine runs right across Llyn Llydaw near the present outlet. It is seen rising into high hillocks on the north side of the lake, projecting as islets from the lake itself, and covering much ground on the south side below the exit. No doubt it is, as Mr. Watts says, J. LE. Marr and R. H. Adie—The Lakes of Snowdon. 59 a thin skin on the surface of the rock in many places. Rock, as he states, occurs in the stream which comes from the lake at a distance of forty or fifty feet below the exit, but the left bank of the stream is bounded by drift for a long way beneath this, and the stream is in places obviously cutting between drift and rock; nevertheless, we do not believe that the old exit was here. Viewed from above, a depression is seen running diagonally across the moraine-covered ground between the two streams mentioned by Mr. Watts, and this depression is marked by some pools, one of which is of sufficient size to be inserted upon the six-inch map. The depression joins the stream south-west of Llyn Teyrn, and the first live rock seen along this line occurs between Clogwyn Aderyn and Clogwyn Pen-llechen, south of Llyn Teyrn, at a vertical distance of nearly 200 feet below the level of Llyn Liydaw. The lesson taught by Llyn du’r Arddu proves that a buried valley need not show any marked traces upou the surface ; and we believe that, even though the greater part of the moraine material forms a thin skin over the rock, a buried channel runs in an easterly direction along the route we have indicated. The water of Llyn Llydaw is described by Professor Ramsay as being “of a green colour, like some of the lakes of Switzerland,” though the difference of colour between the waters of Glaslyn and Llydaw did not appear to us to be very marked when we visited the lakes in the early spring. Above Llydaw lies Glaslyn, at a height of 1,970 feet above the sea, and immediately below the great precipice surmounted by Y Wyddfa, the highest point of Snowdon. The tarn is very in- structive. It is, as Mr. Watts remarks, “ bounded on all sides by live rock, except at and near its outlet. This exit is over moraine, which, however, is not very deep, for rock makes its appearance just below, and in such a way as almost to compel belief in a complete rock- bar. Besides the present course of the effluent stream is a parallel strip of moraine running down towards Llyn Llydaw, but living rock soon makes its appearance in this.” his parallel slip of moraine looks quite insignificant when viewed from the path; but when visited is found to be of considerable width. It joins the main stream at a vertical height of at least 50 feet below the exit, and at the junction a small stream is seen cutting its way backwards in the drift. Between the exit and the junction of this . drift-filled depression with the present stream is a waterfall, and the water has here cut a mere groove in the rock. Moreover, we here meet with a most significant feature: the bottom of the drift-filled depression is at a lower level than the present stream, which runs at the side of the valley, being separated from the lowest part by a low shelf of rock. We here find a repetition of what one of us has previously noticed in the case of the tarn Smallwater, near Haweswater in Westmore- land (Quart. Journ. Geol. Soc., vol. xxi, p. 37), and we believe that the explanation given in that case is applicable to Glaslyn also. There is a feature of interest connected with the outline of the tarn. A bay occurs on the north side, whose shore-line forms a curve 60 J. E. Marr and R. H. Adie—The Lakes of Snowdon. parallel with those of the contour-lines above, where they run round a little valley occupied by a small stream. ‘The existence of this bay is, of course, explicable if the lake be drift-dammed, but is difficult to explain if we suppose that it has been excavated by ice. The colour of the water of Glaslyn is indigo, though the tint is not so deep as that of Llyn du’r Arddu. Here also copper-mines have been worked close to the lake, but, as has been mentioned above, no trace of copper was found in the water. The samples, of which the analyses are appended in tabular form, were obtained under somewhat different conditions in the case of each lake. That from Llyn du’r Arddu was obtained from fairly deep water, surrounded on the landward side by rock in sitd, that of Llydaw from the middle of the causeway which has been made across the lake, whilst that of Glaslyn was obtained from shallow water close to an ordinary foreshore, consisting of loose blocks and some vegetation. ARDDU. LLYDAW. GLASLYN. Parts per million. -, ( Inorganic ie aes Abd 22 22 34 tolls Morea: ne 16 10 12 Hardness (Lime and magnesia salts) ae 22 20 22 Chlorine ee wee ea ee 9 9 12 Nitrogen as ammonia ... : Bes “004 004 a2, re albuminoid ammonia . ee 026 “070 048 Oxygen absorbed in 15 min. beth wide “40 0 “40 4 hrs. aie o00 “40 80 1:20 Nitrog en as nitrates and nitrites ... Bh eALeD 16 “20 We did not think it necessary to determine the organic carbon and nitrogen, as the above results may be generally used as a substitute for them. The analyses show that the waters of Arddu and Llydaw are similar in character: they contain about the same amount and variety of inorganic matter (chlorine, lime, etc.), but Llydaw contains rather more than twice the amount of organic matter that Arddu does, as shown by the albuminoid ammonia, and oxygen absorption in four hours. The similarity of the amount of chlorine also suggests that the organic matter is similar in the two cases. This result is what would” be expected from the relative position of the lakes. The results in the case of Glaslyn are very remarkable. The amount of solids (not lime and magnesia salts) and chlorine, also of ammonia (free and albuminoid), oxygen absorbed, and nitrogen as nitrates, would always be held to indicate the presence of much animal organic matter. This hypothesis seems at first ridiculous from the position of the lake, unless the hotel on Snowdon summit drains in any way into it. The only cther interpretation is, that the sample obtained from near the bank was not of average quality. No impurity of such character could be introduced in any ‘other way. The object of these analyses, viz., to put to the proof M. Forel’s ~ hypothesis of the cause of coloration of mountain lakes, is unfor- tunately not attainable from these results, owing to the peculiarity Dr. Wheelton Hind—Carboniferous Life-Zones. 61 of Glaslyn, so that we must reserve this point for future work on other lakes, further from possible contamination. In the meantime, failing an analysis of peat water of the above strength, there is some evidence in favour of the hypothesis from the cases of Arddu and Llydaw, though we were not able to match the indigo colour of these waters by means of his standard solutions. We failed to find any trace of copper. On a future occasion we hope to furnish more analyses. In an article in Science Progress, new series, vol. i, p. 218 (1897), one of us describes some depressions formed on flat surfaces of rock in the Lake District, owing to the more rapid weathering beneath patches of moss, grass, and heather, which, when removed, leave little basins beneath them; and it was suggested that small lakelets might be produced in this way, especially in’ rocks which contained much soluble material. The depression in question occurred in the volcanic rocks of the Borrowdale Series. ‘l'o show the effect of the weather upon rocks of this nature, a fragment of rock (possibly hardened mud with volcanic matter) was extracted from a peat-bog near Llyn du’r Arddu, and the analyses of the core and of the weathered crust are given side by side :— CORE. CRUST. SiO, es Be 79:20 72-00 Ale O3 08 S00 16°74 22°36 He coo on6 1-96 2°55 Fe, O3 S60 B60 1-28 0°87 MnO a0 coe 0°34 0-41 Alkalies ... ooo 0°67 0-51 Loss on ignition B60 1-11 1°41 101°30 100-11 TIJ.—Novre on toe Lire-Zones oF THE CARBONIFEROUS DeEpostrs or EUROPE. By Wuretton Hinp, M.D., B.S. Lond., F.R.C.S., F.G.S. T has long been a matter of reproach to British geologists that, | with such a grand sequence of Carboniferous rocks as occurs in Great Britain and Ireland, many of which are highly fossiliferous, all attempts to establish life-zones in them have hitherto been un- successful. As a subcommittee, appointed by the British Association, has been put into existence to endeavour to zone the Carboniferous rocks, it seems to me that a preliminary comparison with each other of the life-zones already established in Russia and Belgium, and as far as is possible to contrast the distribution of the zonal fossils with that which obtains in Great Britain, may to some extent clear the ground, and establish some important paleontological facts as a basis for future work. Russian geologists are able to state without any hesitation that certain fossil forms are characteristic of certain zones in the Carboni- ferous rocks of Russia, and that these zones are, with very slight changes, the same for the Carboniferous deposits of Central Russia, the Ourals, and the Donetz basin. Three main stages are recognized 62 Dr. Wheelton Hind—Carboniferous Life-Zones. (with subdivisions and some small local variations), which are as follows :— Upper Zone : Spirifer fasiger, Productus cora, Spirifer suwpramosquensis, Conocardium Uralicum, Schwagerina princeps, Margini- fera Uralica, with coal in the Donetz. Mippue Zone: Spirifer Mosquensis. Lower Zone: Productus giganteus, P. striatus, Chonetes papilionacea, with coal-beds in Central Russia. It is to be noted that in the Donetz basin the biological division between the upper and lower divisions is not absolute, Spirifer Mosquensis passing well up into the beds with Productus cora; but it would appear that Spirifer fasiger, Keys, does not trespass into the zone of S. Mosquensis, and the two fossils are never found together. A large number of widely distributed Carboniferous species are common to all three divisions, but are not so frequent in the upper; and this, in addition, coutains several forms which have never been noted in Western Europe, but which, on the other hand, are recognized as occurring in beds of the Salt Range period of India, and in the Carboniferous beds of North America. Passing to the Carboniferous beds of Western Europe, De Koninck and Dupont are able to recognize three subdivisions in the calcareous deposits of Belgium :— Srace IJJ].—Urrer— Visean (detrital): Zone of Productus giganteus, P. latissimus, P. striatus, P. cora, Chonetes papilionacea. Stace JJ].—Mippitr— WaursortrAn(corallian): Ampleaxus coralloides,Syringothyris cuspidatus, Spirifer striatus, Conocardium Hibernicum. Stace I.—Lowrr— Tournatstan (crinoidal) : Spirifer Tornacensis, S. cinctus, S. laminosus, Syringothyris distans, Athyris Royssit, A. lamellosa, Conocardium fusiforme, ete. This threefold division, however, is not accepted by all Belgian geologists. The Légende de la Carte géologique de la Belgique, dated 1896, shows only two main zones in the Carboniferous Lime- stone of Belgium—Visean and Tournaisian—the assise de Dinant, with Chonetes papilionacea, being considered as a facies of the Visean. The Waulsortian beds are placed as a facies of the Tour- naisian, not typified, however, by any fossils ; and the assise of Hastiére, with Spirifer Tornacensis, S. gluber, and Spiriferina octo- plicata, is considered to belong also to the lower group. Dr. Wheelton Hind—Carboniferous Life-Zones. 63 Gosselet (‘¢ Esquisse géol. du Nord de la France,” 1880) proposes to divide the Carboniferous Limestone of France and Belgium into ten zones, but, judging from the lists of fossils given, probably not on palzontological grounds. He recognizes Spirifer Mosquensis as occurring at horizons below that of Productus giganteus. It will be noted at once that the highest stage of the Carboniferous Limestone of Belgium is characterized by the same zonal form (P. giganteus) as that which is so typical of the lowest division in Russia, and that it is accompanied by P. cora, one of the zonal forms of the highest Russian division. Although, some time ago, De Koninck was of opinion that Spirifer Mosquensis was found in the lowest Belgian (or Tournaisian) stage, in his paper “Sur le Spirifer Mosquensis”’ (Bull. Mus. Roy. d’ Hist. Nat., tom. iii, 1883, p. 873) he showed that he had confounded this species with Spirifer Tornacensis and S. cinctus. In his remarks on the affinities of the latter shell, he states ‘“‘qu’elle en différe essentiellement [from S. Mosquensis] par sa grande taille, et, mieux encore, par Pabsence dans sa valve ventrale des lamelles dentales divergentes, si fortement développées dans celle de sa congénére Russe.” In a later work, De Koninck figures Spirifer spissus from Stage III and S. suavis from Stage II, but these, judging from the drawings alone, I should not, like to say were not varieties or specimens of S. Mosquensis ; certainly they have much fewer ribs than the latter species. I have lately attempted to solve the question whether S. Mosquensis really occurs in Great Britain or not. Originally Davidson figured two specimens in his Monograph on the British Carboniferous Brachiopoda (pl. iv, figs. 13 and 14) which agree very closely with Russian examples. Later on he was led to doubt the correctness of his determination through the influence of De Koninck’s work. Unfortunately one of these figured specimens has disappeared, and probably only that one remains which is in the collection of the Royal Society of Dublin, but I have not been able to examine this example. In the Appendix to the Monograph Davidson figures two shells from Scotland (pl. xxxiv, figs. 3 and 4) which closely resemble S. Mosquensis in shape, under the name S. trigonalis var. bisulcata. Dr. J. Young has kindly compared these shells with a typical Russian example, and says that the Scotch examples have much fewer ribs and that these are thicker. I have, through the kindness of Professor Lloyd Morgan, examined the shell from the Oracanthus bed of the Lower Limestone shales of Clifton named S. Mosquensis by Stoddart, but this reference is an error, the shells having nothing in common. I have also examined a fine series of shells labelled S. Mosquensis, from the Carboniferous Limestone of Co. Cork, in the collection of the Geological Survey of Ireland, I recognize amongst them S. cinctus and S. Tornacensis of De Koninck, but not S. Mosquensis. When placed side by side the differences between these three species are 64 Dr. Wheelton Hind—Carboniferous Life-Zones. very distinct, much more so than one would judge from the remarks and descriptions of De Koninck. Both S. cinctus and S. Tornacensis are more transverse, and possess fewer but thicker ribs, than S. Mosquensis. The construction of the dorsal mesial fold and corresponding sinus in the ventral valve is different in each species. At present, therefore, I am unable to affirm the presence of S. Mosquensis in Great Britain. It is an important fact to note, in connection with the absence of the Spirifer Mosquensis zone in Belgium, that Productus cora and P. giganteus, the typical shells of the first and third zones in Russia, should occur together in Belgium, and that, according to the Belgian geologists, the beds with Productus cora are inferior to those with P. giganteus. In the P. cora zone of Russia the fauna, taken as a whole, is remarkably dissimilar to any that occurs in Western Europe, especially towards the upper portion, most of the species being entirely different. The intimate study of De Koninck’s later monographs cannot but convince the reader that with that author the erection of species was largely secondary to the knowledge of the horizons at which the various specimens were obtained. Starting with the preconceived notion that there were at least three distinct molluscan faunas in the Carboniferous Limestone of Belgium, he seized on the smallest differences in detail or growth as a reason to invent a new species, especially if it had been gathered from a special horizon. He says himself (Ann. Mus. Hist. Nat. Belge, sér. Pal., tom. vi, p. 4): “Siaux caractéres différentiels constatés entre des spécimens provenant Wassises différents quelques faibles, qu’ils soient, vient s’ajouter une constance bien établie, 11 me semble loisible d’admettre que ces spécimens appartiennent 4 des espéces distinctes, et c’est ainsi que je les considererai.” A very large number of the species which De Koninck states are confined to one or other of his three horizons in Belgium, I bave found together in the Carboniferous beds of Great Britain and Ireland, and am inclined to think that many of his species will be found to be merely synonyms. In the voiumes on the Lamellibranchs of the Carboniferous Lime- stone of Belgium, 461 species are described by De Koninck, not one of which is said to occur except in one stage. The numbers are as follows :— Etage Viséen . . . . 222 species aa. a \Wemllsorinens 3 6 UBS) 5, 1 LOUEMaISICniea area Ol mm. 461 The species of Brachiopoda also are supposed to have had the same limited distribution, for not one of the 130 species described is common to two stages; and out of 499 species of Gasteropoda described only one species, and that with a query, is supposed to be present in two horizons. Thus De Koninck would have it that there are three absolutely distinct faunas, which never intermingle or a Dr. Wheelton Hind—Carboniferous Life-Zones. 65 overlap. However correct these facts may ultimately be shown to be in Belgium, there is in the Carboniferous beds of Great Britain and Ireland nothing at all comparable to such exactness in the vertical distribution of the faunas of the Carboniferous period ; and if one fact is emphasized more than another, it is that many species of Brachiopoda and Mollusca reappear again and again at various horizons, and survived throughout the whole of the epoch. In Great Britain, Productus giganteus is a fossil very frequently met with, and of very wide vertical range. In the Pennine area it is met with in all the limestones from the Great Scar to the Crow Limestone, thus passing from the base of the Carboniferous Limestone to the top of the Yoredale Series. In Northumberland, it occurs with P. cora throughout the whole of the rocks grouped by the officers of the Geological Survey as the Carbonaceous division ; and in Scotland is characteristic of the limestones of the Carboniferous Limestone Series, both upper, middle, and lower divisions. In North Wales, P. giganteus passes from the Middle White Limestone of Mr. Morton to the top of the series, accompanied in the Middle White and Upper Grey Limestones by P. cora, which shell is found alone in the lowest member (the Lower Brown Limestone) of the series. In South Wales, Mr. Morton finds P. giganteus and P. cora in the limestones of Gower, and Mr. Stoddart records both these fossils in the Carboniferous Limestone of the Bristol district. Mr. Stoddart published (Proc. Bristol Nat. Soc., new ser., vol. 1, 18746, p. 318) a very careful account of the various beds of the Lower Carboniferous Shales and Carboniferous Limestone of the Bristol Coalfield, and the fossils contained in them. ‘The majority of the Mollusca and Brachiopoda are not, however, zonal forms, but are found at various horizons in the Carboniferous series, both there and elsewhere. M. Max Lohest, after going over the ground, published a small pamphlet entitled “Sur le parallélisme entre le Calcaire Carbonifére des environs de Bristol et celui de la Belgique ” (Ann. Soc. Géol. Belge, tom. xxii, p. 7),in which he would establish an almost complete identity between the Bristol and Belgian series. This author recognizes zones indicated by A, B, D, H, F. A. Beds with Modiola Macadamii and Avicula Damnoniensis, which correspond with those of Comblain au Pont. Mr. Stoddart, however, pointed out the close connection of the fauna of these beds with that contained in the Marwood, Coomhola, and Moyola beds. — B. This bed is a red crinoidal bed, with Spirifer glaber, 8. bisul- catus (?), S. Tornacensis, and Spiriferina octoplicata, identified with the lower part of the Tournaisian beds of Belgium; but, with the exception perhaps of Spirifer Tornacensis, all the other fossils are found in the zone of Productus giganteus, if not near Bristol, in the topmost beds of the Carboniferous Limestone of Derbyshire and Yorkshire. M. Lohest says: ‘‘ Le base du terme B parait bien étre Péquivalent de notre assise 4 Spirifer glaber; les schistes du sommet représentant nos schistes a Spiriferina octoplicata”; but in Great Britain both these forms are most abundant in the upper part of the Carboniferous Limestone. DECADE IY.—VOL. V.—NO. II. 5 66 Dr. Wheelton Hind—Carboniferous Life-Zones. D is a bed of crinoidal limestone. EB is a bed of dolomitic crinoidal limestone. F is a thick oolitic limestone, which is considered to correspond with the base of the Viséan, with Productus cora in the lower part and P. giganteus above. In this succession, Dupont’s Waulsortian division of Belgian rocks is entirely absent, and the chief features on which the identification of the two series of beds is based are purely petrological, and not paleontological. There are so many horizons at which beds of crinoids occur, that unless species can be recognized, such statements are utterly valueless for the purposes of identifying horizons. The Avon section shows the following sequence :— Zone of Produetus cor’ ( Mountain Limestone, 2,000 feet. and P. giganteus Prod ucius gaganigus amd Lower Limestone Shales, 500 feet. P. cora absent Tn a paper published in the Annales du Soe. géol. de Belge, tom. ix, 1881-2, p. 31, De Koninck, describing some new Cephalopoda from the Carboniferous Limestone of Ireland, gives three lists of fossils which he considers as typical of the three series of beds established in Belgium by Dupont, and states that he is able to make out the same three zones in Ireland from the study of specimens in various museums and collections. He considers that the following parallels occur : — TRELAND. BELGIUM. 1. Limestone of Armagh. Caleaire des Ecaussénes et de Comblain au Pont. 2. Caleareous schist of Hook Point. Calcaire de Tournal. 3. Limestones of Rathkeale and Calcaire de Waulsort. Co. Limerick. 4, Limestones of Cork, Dublin, Calcaire de Vise. Galway, and Meath. : If a comparison be made between the lists of Carhoniferous fossils from these districts which were drawn up by the late Mr. Baily for the Memoirs of the Irish Geological Survey, it will be seen at once that no such paleontological divisions can be shown for the Irish Carboniferous beds. Indeed, most of the species on which De Koninck relies for the identification of his three life-zones are not confined to the horizons which he mentions. For example, Zaphrentis cylindrica, Syringothyris distans, Spirifer laminosus, Athyris Royssit, A. lamellosa, and Orthis Michelin are said to be characteristic of the Tournaisian; but in-Great Britain and Ireland these shells are found to have survived all through the deposition of the limestones, being not at all rare in the upper beds. ‘The fossils of the middle zone are equally associated with those of the upper and lower in British localities, while Productus giganteus and P. cora are by no © means confined to the upper beds. For example, P. giganteus occurs at Hook Point in the Lower Limestones with Syringothyris cuspidatus, Dr. Wheelton Hind—Carboniferous Life-Zones. 67 Spirifer striatus, S. laminosus, Orthis Michelini, Conocardium fusiforme, Athyris Royssii, and Ampleaxus corolloides. At Armagh, Productus gigauteus occurs at twenty-five different localities, at one of which it is known tooccur with Orthis Michelini, Spirifer laminosus, and Zaphrentis cylindrica; in fact, unfortunately for De Koninck’s rapid generaliza- tions, Productus giganteus occurs in all the Carboniferous districts of Ireland, and seems to have survived from the deposition of the Lower to that of the Upper Limestones. Although copious lists of fossils and localities are accurately given in most of the Memoirs of the Geological Survey of Ireland, it is a great pity that those who had to produce tbem did not see fit to arrange the lists of fossils according to the horizons, instead of only giving localities, and leaving it to the student to identify the horizon of each locality by a reference to the colour which is shown on the map at each place. In the Memoirs of the Scotch Survey, and the later English one, the reader is able to see at a glance not only the locality, but the actual horizon whence each fossil was obtained. It would therefore appear that in Great Britain the zone of Pro- ductus giganteus is very largely developed. In the Southern Pennine district this fossil characterizes the beds from the base of the Lower Scar Limestone to the Upper Limestone (the Crow) of the Yoredale group. In Scotland, however, and, to some extent only, in the Pennine and Bristol areas, this extensive zone is preceded by a series of rocks in which this fossil is absolutely wanting—the Calciferous Sandstone Series, which are probably represented only by the base- ment beds of the Ingleboro area and the Roman Fell beds further north. It is difficult to suggest a zonal form for this series, much of which is non-marine; but on the Fifeshire coast Sanguinolites Abdensis, Etheridge, and Schizodus Pentlandicus, Rhind, seem to be confined to the series; and Modiola Macadamii is characteristic of the Lower Limestone Shales of Bristol and the Coomhola and Moyola beds of Ireland. The shales overlying the limestones in Derbyshire and Yorkshire, I have shown to contain a fauna totally distinct from the Carbon- iferous Limestone and the Yoredale beds of Wensleydale (Gnot. Maa., 1897, Dec. IV, Vol. IV, pp. 159-169 and 205-213). This series, mapped by the officers of the Survey as Yoredale beds, may be described as the zone of Aviculopecten papyraceus, Gastrioceras carbonarium, Posidoniella minor, and P. levis, and includes the Lower Coal-measures or Ganister Series, Millstone-grits, and shales below them; while the Coal-measures may well be subdivided into the upper, or zone of Anthrucomya Phillipsii, and lower, or zone of Naiadites modiolaris, with many local horizons at which only certain fossils have as yet been known to occur. The following table gives the equivalents of these zones in England, Scotland, and Ireland, from above downwards :— 68 Dr. Wheelton Hind— Carboniferous Life-Zones. 1: Zone of Anthra- comya Phillipsi. 2. Zone of Naiadites modiolaris and Anthracomya modiolaris. 3, Zone of Aviculo- pecten papyra- ceus, Gastrioceras carbonarium, Posidoniella levis, and P. MANO?» 4. Zone of Pro- ductus giganteus and Productus cora. 5. Zone of Modiola Macadamiz. ENGLAND. ScoTLAND. IRELAND. Upper Coal-measures | The Red Beds of Fife- | ? Wanting. of Lancashire, York- | shire. ‘ shire, Staffordshire, Bristol, including the Spirorbis Limestones. Middle Coal-measures universally. Ganister Series. Millstone Grit. Shales below the Mill- stone Grit universally. The Carboniferous Limestone of Derby- shire. The measures from the Great Scar to the Main Limestone, N. York- shire. The Carbonaceous Division of North- umberland. Carboniferous Lime- stone of Wales and the Mendips. The Lower Limestone Shales of the Mendips and South Wales, with several fossils common to the Old Red Sand- stone Series and the Carboniferous. The Red Beds of Fife- shire. ? Wanting. Norr.—Aviculopecten papyraceus is said to be found some distance above the Ell Coal in the Wishaw district, Lanarkshire; but Ihave '| never seen this fossil in any Scotch collection, and the determination is possibly erroneous. The Carboniferous Limestone Series of Upper Scotland , Middle Lower. The Calciferous Sand- stone Series, with Schi- zodus Pentlandicus and Sangquinolites Abdensis inFifeshire,andafauna very different from the English and Irish equi- valents. Mr. Kirkby states that Productus cora is contained in the upper 500 feet of these beds. Coal-measures. Castlecomer, Leinster Coal- field. Coal - measures of Fynes, co. Limerick. The Upper Limestone, The Calp. The Lower Limestone. The Coomhola and Moyola beds, forming a pas- sage from the Old Red to the Carboniferous, and containing certain fossils common to both. Series 1-8 constitute what I consider to be the “‘ Upper Carbon- iferous,” and series 4 and 5 the ‘“ Lower Carboniferous,” of my paper on the Yoredale Series (Grou. Mac., April and May, 1897). While the zone of Productus giganteus corresponds to the Viséen of Belgium, the lower zones of Great Britain do not resemble the W. M. Hutchings—Rocks of Great Whin Sill. 69 Waulsortian or Tournaisian in their faunas. My own view, from a comparison of the Belgian and British fossils, is that the zone of P. giganteus in Great Britain and Ireland corresponds to the whole of the Belgian series; for none of the fossils which are relied upon by MM. De Koninck and Lohest to identify the lower beds in both areas are in Great Britain and Ireland confined to the Lower Limestone Shales, but are found in abundance, and in a full condition of growth, at the top of the zone of P. giganteus. The faunas contained in the beds of shale differ markedly from those contained in limestones, the shales being much richer in Lamellibranchs and Crustaceans, and comparatively poor in Brachio- pods and the Actinozoa. Consequently the faunas of the same zone, taken as a whole, vary very much according to locality and the nature of the sediment. Consequently the zone of P. giganteus in Scotland, in which the limestones are separated by thick beds of shale, contains a very different fauna from that which obtains in the same zone in Derbyshire, where the shales are practically absent, and the limestone exists in one mass, made up of beds of various lithological characters. IV.—Twe Contact-Rocks or tHe Great WHIN SILL. By W. Maynarp Hurtcutnes, F.G.S. N what follows, it is proposed to give a general description of the effects of contact-metamorphism, observed in the rocks altered by the intrusion of the Great Whin Sill in Durham and Northum- berland. The work, of which this is the condensed result, has been carried on for the last four years in the microscopical, and to some extent chemical, study of a large series of specimens collected at many points along the course of the Whin Sill exposure by Mr. E. J. Garwood, and also, to a very much smaller extent, by myself. Mr. Garwood has been for a long time engaged in a detailed examination of the geology of the district, and will in due course publish the results of his work, which is not yet complete. It was at his suggestion and request that I undertook the petrological study of the specimens collected. As is well known, the rocks into which the Whin Sill mass has been intruded consist mainly of limestones, shales, and sandstones of the Lower Carboniferous beds. The special interest and value of the contact-effects here displayed, are enhanced by the fact that the rocks acted upon were all in what may be called a perfectly simple and elementary state. We know exactly what they were like before they were altered by the intrusion, and can study them as fully as we wish, in their original and normal condition, in the same and other districts. Thus, the shales, the metamorphism of which gives us the most interesting portion of the material, with the most important bearings upon the question of contact-action in general, are in all respects counterparts of those from the Coal- Measures and the Lower Carboniferous, which I have described in 70 W. M. Hutchings—Rocks of Great Whin Sill. full detail in previous papers in this Magazine. None of the rocks affected had undergone any sort of “‘development” previous to the intrusion of the Whin; and as they have not been in any way changed, except by weathering, since the consolidation and cooling of the igneous mass, we are able to see with considerable certainty just what mineralogical and structural changes are to be ascribed to contact-metamorphism. Such comparatively simple and reliable conditions, in a contact- area of such importance, are so very rare that it is at once apparent how valuable are the indications we may derive from them, and how great is the assistance they may render to us in our endeavours to understand the much more complex cases usually presented to us. I say “in a contact-area of such importance” because, as I shall show, we have here exactly reproduced for us a large portion of the phenomena we are accustomed to see round the intrusions, on a much mightier scale, of granite, etc. It makes no difference that in greater contact-areas the mineralogical and structural details are more striking as to size, so long as on the smaller scale they are equally clear and distinct. I propose to deal with the altered rocks in the following order : pure or almost pure limestones, argillaceous limestones, shales, calcareous shales, sandstones. These, however, pass over into one another in all degrees, and there is, of course, no sharp division between limestones, argillaceous limestones, calcareous shales, shales, quartzy shales, argillaceous sandstones, and sandstones or grits. It is among some of the intermediate rocks that the most interesting effects are produced. When a sufficiently large number of specimens had been sliced and examined, it became evident that there was no use in multiplying them beyond a certain point. It was clear that the same results of alteration could be found at intervals all over the long course of the Whin Sill, wherever the chemical nature of the invaded rocks was the same. For this reason, in the following descriptions, particular localities of occurrence will only be men- tioned when specially interesting or pronounced developments have taken place, which are qualified to serve as good types of the alterations in general. Commencing, then, with the limestones, we find that when these are pure, or at all events are non-argillaceous, the action of the Whin Sill upon them has been limited to a recrystallization of them. In some cases this recrystallization is very finely marked, and may stand alongside of the “marmorization” of similarly pure lime- stones by intrusions of granite. Whether interfusion has taken place to any extent between the Whin and the purer limestones, at some points, is a question which it is not possible to answer decisively. In many actual contact- slides examined there does not seem to be evidence that any such action has occurred at all; the division line is quite sharp and clear, the Whin is small-grained but quite crystalline right up to the junction, and the recrystallized limestone begins equally sharply on W. WM. Hutchings—Rocks of Great Whin Siil. va the other side of it. If there be recrystallized quartz, this also often comes quite sharply up to the contact-line. _ In some instances there does appear to be a very narrow streak of more indefinite matter, possibly denoting interfusion ; and there are other cases where a very noticeable band is seen of what has clearly been of a tachylitic nature; though whether we ought to regard it as a true tachylite,—i.e. a product simply of rapid cooling of the edge of the molten igneous rock,—or whether it is more a result of interfusion, I think cannot be settled, because chemical analysis would not here give a sufficiently definite answer. So far as microscopical evidence can help us, I rather incline to the view that it points to interfusion having taken place to some extent. Thus, the most striking example is one from Middleton Wood, near Belford. In the hand-specimen the tachylitic material was some two inches thick, and in the slide prepared from it, over the line of contact, there is nearly half an inch of it. The limestone is simply crystallized, as is also silica which it contained. It has not had any new minerals formed in it, but quite close to the junction there are a few colourless garnets, just a narrow string of small crystals and grains. ‘Then comes the tachylitic band, mainly a yellow to red- brown glass, with a good deal of indefinite, speckly, felsitic-looking matter, and chloritic decomposition products, but with some felspars and augites of good size dispersed in it, and a few prisms of enstatite. With these is also a good deal of garnet in small grains, and at some parts patches of it of much larger size. As no garnet occurs in the altered limestone except at the actual contact, and as it occurs in the tachylitic band, it seems likely to be a product of the interaction of limestone and Whin. No garnets seem ever to occur in the normal Whin Sill rock. In some other specimens examined there is, again, a narrow band of what appears to be another product of such interaction. There is a seam of what appears to have been tachylitic, now very much obscured by calcite and chlorite due to decomposition. The lime- stone is perfectly free from any new mineral formation. But on the side towards the Whin comes a zone of close-grained igneous rock, a narrow strip of which is coloured brownish-red of a peculiar shade. Under higher powers it can be made out that this reddish band contains swarms of minute flakes of mica, and that it is from these that it derives its colour. Here and there the compact swarms of this mica open out, and become more scattered and larger in size, some individuals being seen as fairly well-bounded crystals, which can be recognized as a deep brown-red very dichroic biotite, some of the best flakes giving a good optic figure in convergent lght with 54; inch objective. None of this mica is ever seen in the normal Whin, and I have not seen any signs of it except at contacts with pure limestones. It certainly appears to be an endomorphic formation in the igneous rock, brought about by interaction with the limestone, though it does not seem easy to explain the chemical re- actions which have been concerned in it. 1 do not recollect any mention of a similar result on an intruded igneous rock, and have Certainly never seen it myself in any other case. 72 W. M. Hutchings—Rocks of Great Whin Sill. We will now pass on to the altered argillaceous limestones, including under that head all such rocks as are still safely to be recognized, microscopically and chemically, as having been dominantly limestones, but which have contained sufficient shaly material to provide a noticeable amount of silica and alumina, with some alkali and magnesia, which latter will also be present, more or less, in any case, in most of the limestones. Rocks of this class, of varying degrees of admixture, occur at many points along the Whin Sill, and have given rise to very interesting contact-products. The new minerals formed are garnet, augite, idocrase, wollastonite, epidote, hornblende, felspar, chlorite, sphene. The garnet is the most persistent, being seen in all the slides examined from rocks of this class, whereas most of the above minerals may be present in some cases and absent in others. One or two typical examples will serve to give a general idea of the nature of the alterations produced. Thus, from specimens of not very impure limestones from Burtreeford, sections have been cut which show the actual contact-line. First comes a narrow band (about 345 inch) which seems to mark some sort of interfusion. Thongh now much obscured by fine-grained secondary calcite, it is distinctly defined both on the side towards the Whin and on that towards the limestone. The Whin is very fine-grained, but contains a good many perfectly fresh and distinct crystals of felspar of larger size. Occasionally one of these crystals projects just into the edge of the interfusion-band, and may be seen to have been melted away in it and left with a rounded end. Along the edge of the band towards the limestone lie many small but good crystals, and some irregular grains, of idocrase. The largest crystal in these particular slides is a prism <5 inch long by i30 inch wide, very fresh and perfect. A very few lie also a little further in, but none occur at any distance from the contact-line. It is interesting to note the mode of occurrence of these crystals, some of which are completely bedded in quartz, some again in calcite, and others in grains of calcite which are surrounded by quartz. Then comes another narrow zone, about -2; inch, which consists largely of recrystallized quartz as a sort of ill-defined mosaie, intermixed with varying amounts of calcite. This quartz is all full of inclusions of small garnet grains and indeterminable microlites, and clearly dates from the original metamorphism of the limestone by the intruded Whin, being strongly distinguished from later quartz which has filled in small cracks, etc., and which contains no such enclosures. This quartz band passes abruptly into coarse- grained, highly crystalline, saccharoid limestone, the calcite crystals containing numerous small garnets in rounded grains. A deep- coloured, very dichroic sphene, in good-sized crystals and grains, is also present. Rather more impure limestones are represented by specimens from Rumbling Churn, near Dunstanburgh. Garnet is again very abundant, mainly in very small crystals and rounded grains W. M. Hutchings—Rocks of Great Whin Silt. 73 averaging about y5s5 inch in diameter, but in some cases reaching +t inch and a little over. At some parts of the slides these garnets are packed so close that scarcely anything else is visible. They vary from colourless to yellow and greenish, and some are a rich red-brown. Often the centre is coloured, and the outer rim is colourless. Augite occurs plentifully with the garnet, in good-sized crystals and large irregular complex grains. It is all perfectly fresh, and some of it is of a very decided green colour, and slightly dichroic. Both garnets and augite come right up to the contact-line, and in one slide may be seen lines of very small augite crystals, clearly of contact-origin, growing out from the edge of the Whin, like the teeth of a saw, into the lime- stone. A very pale hornblende in slender needles is also present at some parts; epidote and sphene are well represented, and there is a good deal of recrystallized quartz, which frequently encloses garnet and augite. The remaining calcite of the limestone is completely recrystallized. There are often large fields of one uniform grain of it, with numerous garnets and augites contained in it. In the mosaic of recrystallized quartz in these highly calcareous rocks one may often suspect felspar to be present, but without being able to make sure of it, owing to «absence of cleavages and the impossibility of making reliable optical tests. In one specimen from near Dunstanburgh, however, an altered limestone shows numerous small crystals, together with more or less irregular grains, of well- cleaved fully-individualized felspar. Some few of the crystals even allow of identification, with much safety, as anorthite or a closely- allied species (sections with parallel cleavage, extinctions 30°-40°, with emergence of good axial bar inside the field). They le in amongst very coarse-grained recrystallized calcite, near the junction with the Whin. It will be seen later on that some of the altered shales contain abundant new felspar. The above specimen shows also a few garnets, some epidote, a good amount of recrystallized quartz, together with a considerable amount of wollastonite, mainly in tufts and bunches of often sheaf-like, radiating fibres, with here and there bits of sufficient size for the application of optic tests. This mineral appears to be not of frequent occurrence in these rocks. Indeed, it may be noted that, so far as concerns the lime- stones which are reasonably free from any admixture except silica, there seems seldom to be any reaction between the lime and the silica. Calcite and quartz recrystallize side by side, and it is rare to see in these particular rocks any formation of wollastonite, or of any calcareous hornfels-like products, such as are more frequently encountered round granite-contacts. Sometimes there were little bands of sandstone in the pure lime- stone, quite close to the contact. A specimen from near the Roman station of Borgovicus, close to the Whin, is sliced so as to show both recrystallized limestone, very saccharoidal, and sandstone converted into a well-cemented quartzite, with some new felspar among the interstitial matter. The division-line of the two products is very elear and sharp, and there las not been a trace of action between them. 74 W. M. utehings—Rocks of Great Whin Sill. It is not only close to contact that these limestones have been affected. Complete recrystallization is seen at more than 60 feet away, and small augite crystals are seen in a specimen over 40 feet distant. We may now turn to the consideration of the alteration-products of the shales. These shales along the contact-area of the Whin Sill have varied in nature in every degree, from argillaceous beds almost quite free from quartz, to others in which that mineral ‘has formed a large proportion. For our present purpose we will call them all shales, speaking of them as more or less sandy, and only draw the line where the quartz has increased so largely that we must recognize them as argillaceous sandstones and classify them accordingly. Of this class of rock a very large number of specimens have been examined, but here again a few examples will suffice to give a clear idea of the general lines on which the metamorphism has proceeded. The intensity, and to some extent also the character, of the alteration varies more or less at different places. This is partly due to different composition, notably the variation in the amounts of quartz and of alkalies contained affecting the susceptibility of the beds to contact-action. Partly it is due also to the varying bulk of the intruded rock at different points, and sometimes we cannot account for the variation except by assuming some difference in the local conditions of the invaded beds, as to | temperature, degree of hydration, etc., before the intrusion occurred. Outwardly the change undergone by the originally soft shales consists in great induration, accompanied by more or less lightening of colour. In the inner zones of action, nearer the igneous rock, (sometimes also at considerable distances), the soft, fissile, dark- coloured shale has been altered into a hard, compact, grey or greenish-grey rock, with often very little fissility remaining, and in many cases completely replaced by a conchoidal or almost flinty fracture. Inwardly, as revealed in thin sections, the most constant and striking change lies in the production of new mica, with chlorite, with a totally new structure as well as new mineralogical com- position. Newly erystallized quartz is also frequently a main feature, in some cases felspar has been abundantly produced, and we have examples of the appearance of special contact-minerals in the form of biotite. andalusite, anthophyllite, ete. If we take first the purest shales, which have had little, if any, quartz, and which have a chemical composition like that of some of the purest “ fireclays,” we find that where the contact-action has been most intense we have a complete recrystallization of the entire rock, with formation of a new mass of white mica throughout. Instead of the minute flakes of the indefinite micaceous mineral which has been produced in the fireclay or shale, making its main constituent, and lying nearly all in one plane, we get a network of much larger, well-developed flakes and crystals of white mica, — lying criss-cross in all directions. In many cases a good deal of it is grouped together in fans and sheaves, and roughly spherulitic W. M. Hutchings—Rocks of Great Whin Sill. 79 ageregates giving more or less black-cross figures in polarized light. Intimately mixed and interwoven with this new mica is an abundant chloritic mineral. This chlorite forms part of the sheaves and spherulitic groups, and all over the slides is seen to have been formed flake for flake with the mica, as a result of one and the same process. No such chlorite exists in the unaltered beds; as I have previously pointed out, both it and the white mica are the result of a splitting-up and higher development of the impure and complex micaceous mineral of the clays and shales. In some cases there is a certain amount of biotite formed, with a similar mode of occurrence, but this is not frequent among these rocks. The formation of “ spots”? may also be seen on a copious scale in some specimens; and these spots, though small, are exactly analogous to the larger ones seen at some granite contacts, being due to the agerevation of the chloritic material which is separated out during the recrystallization of the rock constituents. One or two special examples of the alteration of these pure shales may be given in illustration. Thus, a specimen from Rowntree Beck, taken 18 feet below the Whin, is very highly altered but still contains good fossils. An analysis of it gives— Siltcayy ess 600 Bas cs aah 51°40 per cent. Alumina ... Re Be as ae 26°85 95 Ferric Oxide! ... ee ine 50 6°15 a Lime Bae sare Bae Bao a8 0°56 59 Magnesia ... oC 568 565 se 2°38 5p Potash mat BN ae Ma 5°21 1) Re Sod te Umesh ate h ee (enema are veeer (OMe Ene a W ater 6°45 9 100°78 This composition shows the rock to have been originally of the nature of a fireclay, closely resembling some of the series of which I published analyses in a former paper (Grou. Maa., 1894, Dee. IV, Vol. I, pp. 36-45 and 64-75). 1t is now a muscovite-chlorite rock, with abundant ‘‘ spots” all over it. Into these spots is concentrated nearly all the pigmental matter of the rock, together with chlorite and numerous dark grains and microlites, so that the spots are dark in a light field. Parts of this field are almost clear and colourless. In polarized light they are seen to consist of an interlacing mass of muscovite and pale chlorite. Sheaves and spherulitic bundles of mica and chlorite abound all over the section, and there is no sign of any definite orientation of these minerals in any direction. The entire rock is crowded with small grains and crystals of rutile re- erystallized from the original ‘“‘ needles” of the shale. Another interesting spot-rock comes from near High Force. In ordinary light a section of it shows a sort of marking off into roughly polygonal, or approximately circular, clear spots, framed in 1 Tn this and following analyses a// the iron is reported as ferric oxide, no special determination having been made of the portion which is always present as ferrous oxide. his often causes more or less excess in the totals, but is not of any im- portance for the purposes for which these analyses were made. 76 W. M. Hutchings—Rocks of Great Whin Sill. darker greyish and brownish pigmental matter. The spots are mostly of a very pale greenish colour, and proper illumination enables us to see countless flakes and crystals of a chloritic mineral. With crossed nicols the whole slide is resolved into a network of muscovite flakes, lying again in every possible direction, and amid the brightly polarizing mass of this mica the chloritic spots are more or less dark and isotropic. In‘some the transition from the bright frame of mica is quite sharp; in others mica projects more or less into the spot, and only the centre is free. Many spots show a field of quite isotropic, pale-green substance, in among which a dim and speckly fine-grained mosaic polarization is discernible. These spots are again in all respects exact counterparts of what may be seen at some granite-contacts. It is curious to observe that, whereas in the previous example the dark pigmental matter has concentrated inside the chloritic spots, in the present case it has remained completely outside them, and is mixed in with the mica. I have made no analysis of this rock, but it shows only a very small amount of recrystallized quartz, and is no doubt very closely the same in composition as the last. No trace of clastic muscovite remains in either of these, and, indeed, in nearly all the highly altered fine-grained shales examined, it has absolutely disappeared and entered into the same complete recrystallization which has affected the main mass of secondary micaceous and other material of which the shales and clays were composed. Perhaps among these very fine shales examined, the most interesting case is shown in a specimen from near Winch’s Bridge, in Teesdale. It is from a body of rock which has been caught up by the Whin. It contains— Potash ... ees ae ae eas 5°71 per cent. s Soda eres 060 COO eae eos 1-49 ” jt 2p Water ... ie ave ue ad 7°40 99 This is very nearly the maximum of alkali which I have found in any of the carboniferous shales and clays. It can have contained but little quartz. When it is examined under the microscope it is seen to consist, to a very large extent, of the peculiar substance which I have previously described in detail as being found in varying quantity in so many altered rocks around granites (Gunon. Mae., January and February, 1894). I traced and described its various modi- fications and developments, and endeavoured to show the probable nature of its origin and the part it plays in the changes going on during contact-metamorphism. There seems every reason to regard it as a product of the so/ution, or “aqueous fusion,” of original materials preliminary to recrystallization. Sometimes we see it in a quite amorphous state. Its first stage of development from this shows a faint minutely-speckly polarization. At very thin edges, with high powers and suitable illumination, it is seen to be very finely granular. We can see it in contact-slates in all stages of evolution, from — the first appearance in it of very few and smal] mica-flakes, up to a full development of new mica out of it. W. M. Hutchings—Rocks of Great Whin Sill. 17 J alluded, in the paper referred to, to the fact that this substance could be seen in the contact-rocks of basic intrusions, but in less amounts than at granite-contacts. I had not at that time seen the specimen we are now considering, which shows the substance in greater amount than any other I have ever seen, and which strikingly confirms the view at which I had arrived concerning its origin and nature. It here forms a sort of base, or groundmass, all over the slide, and is nearly colourless, there being very little iron present. None of it is quite amorphous, but it has the speckly minutely felsitic polarization. Mica has formed in it throughout, but not regularly diffused, so that whilst at some parts there are patches, large enough to fill the field of.a half-inch objective, in which but a few small distinct flakes are to be seen, we have other portions made up so entirely of mica that little of the base-substance can be seen among it. We can trace the growth of the mica in all stages. It is to a large extent in tufts and sheaves and rosettes ; - many of these of all sizes, as well as single flakes and crystals, and crossed and interlaced groups of them, may be seen brilliantly polarizing, floating free, as it were, in the nearly amorphous material out of which they have grown. It is quite clear that what we here see is an intermediate stage,— an interrupted development,—on the road towards some such final product as the two examples we have just been studying. Had the conditions suitable for the crystallization of the mica continued long enough, we should have had a complete and uniform develop- ment of that mineral, together with its attendant chlorite, as before. But it is just the fact that the conditions did noé continue long enough for completion of the process, which gives such particular interest and value to this occurrence. Such interrupted cases, when we can get them, are capable of teaching us more of what actually “goes on” in these contact-metamorphisms than any number of completed examples, where often all trace is lost of the steps by which the final result has been arrived at. The rutile of the altered shale has crystallized out in much larger and more definite crystals than the original needles, many of them as “hearts” and ‘kites,’ and the entire slide, mica as well as base-substance, swarms with them. A good proportion of the mica, in this case, is brown and strongly dichroic, especially some of its larger tufts and sheaves. There is no clastic quartz remaining ; what little there was evidently entered into the general process of solution, and has reappeared as newly-formed mineral. It is also interesting to notice how the numerous small zircons of the original shale have resisted, as they so frequently do, the solution which has destroyed all trace of everything else, and how they remain quite unaltered among the new products. The greater number of shales affected by the Whin Sill have not, however, been as purely argillaceous as the above examples. They have mainly been more or less sandy. But their alteration has proceeded on much the same lines as those described, and it will not be necessary to consider them in much detail. In some of the more 78 W. WM. Hutchings— Rocks of Great Whin Sill. highly metamorphosed beds all original quartz has disappeared, and has been replaced by newly-formed contact-quartz. Where the amount of it is sufficient, we sometimes get a good “mosaic” of the same nature as what we see so universally at granite-contacts. Where there is less of it, we see it disseminated among the micaceous part of the rock in single grains, and groups of grains. In less intensely affected cases we get more or less clastic quartz remaining ; sometimes it does not seem to have been attacked at all, and again, we may be able to see various degrees of its attack and corrosion by the processes of solution which took place. With the more or less regenerated quartz we nearly always see that the argillaceous position of the shale has given rise to just the same products as those we have been considering, the mica and chlorite, the spots, and the residual speckly substance, all appearing in the same relationships as to individual forms and general structures. Among these altered sandy shales, however, there are some occurrences which are of such special interest that they must be here alluded to, in connection with the review of the whole contact- phenomena of the Whin Sill and their bearings on the general question of contact-metamorphism. In a former paper (“An Interesting Contact-Rock,” Gron. Mac., March and April, 1895) I gave minute descriptions of the rocks to which I allude, and I would refer students of the subject to that paper, limiting myself here to a recapitulation of the particular points involved. The principal rock in question is a bed of shale 8 feet thick, at Falcon Clints. It occurs 75 feet below the Whin, a series of limestones, sandstones, and shales intervening. It contains at some parts large numbers of approximately spherical nodules like peas. Thin sections show, in ordinary light, a grey groundmass in which are bedded grains of clastic quartz. In polarized light it is seen that this groundmass consists largely of an isotropic substance, in which he numerous grains, rounded, irregular, or more or less definitely-bounded, of newly-formed quartz and some felspar. At parts these grains are so numerous and closely packed that they amount to a true interlocking mosaic, with very little isotropic matter. At other places they are more separated, and we get quite large spaces of the isotropic substance, but containing small flakes of mica and other things. These grains are not yet fully indi- vidualized; they are not water-clear, and have still so much dimness about them that they cannot be properly made out at all except in polarized light. They are absolutely distinguished from the original clastic material; not one of them could ever for a moment be mistaken for anything but a newly-formed secondary product. The clastic quartz-grains remaining are seen to be all more or less attacked and corroded by the surrounding groundmass ; their original angular outlines are in nearly all cases preserved, but the outer portions are no longer quartz, but an altered substance often — containing a considerable amount of white mica and sometimes of felspar, whilst in some cases anthophyllite and andalusite are seen. W. M. Hutchings—Rocks of Great Whin Sill. 79 Tn the nodules considerable fields of clear, almost colourless, quite isotropic material are seen, in which bundles and sheaves anil pseudo-spherulites of felspar, with some quartz, have been formed. Anthophyllite and andalusite are also seen in some of them. Here, again, we have preserved for us one of those interesting eases of interrupted development. All the finer-grained material of the shale,—the impure micaceous mineral and the minuter quartz, —has been taken up into solution, or aqueous fusion; and out of the substance so formed a mosaic of quartz with some felspar, together with muscovite, has been in process of crystallization. But this process was arrested before it was complete, and so we are again able to see the unfinished stages, to observe the residual indefinite, isotropic, intermediate matter, and to note also the larger quartz- grains which were being attacked and dissolved, and would have all disappeared if the solution stage of the contact-action had been able to continue somewhat longer. Sections from other parts of this bed show us mainly a fine- grained aggregate of newly-formed quartz and felspar, passing down into a quite cryptocrystalline felsitic-looking mixture (adinole), but opening up, on the other hand, here and there into numerous clear and glassy patches, which in polarized light are seen to consist of groups of well-twinned plagioclase felspar, which can often be identified as albite, whilst the extinctions also point to the presence of a species allied to oligoclase. From the neighbourhood of Rowntree Beck, again, come specimens of shale altered to adinoles, and showing nodules up to two inches across, with anthophyllite. We come now to the calcareous shales, and find that among these we have some of the most intensely altered rocks of all. Sometimes they occur as narrow bands in connection with purer limestones, sometimes as patches and lenticular masses in such limestones, and sometimes as thicker independent layers. The most striking occurrence is at Falcon Clints. The specimens show a compact hornfels-like brown rock, with a jaspery sort of appearance and fracture. It contains many garnets of sufficient size to be easily seen with the naked eye. ‘Thin sections show that these garnets are the most prominent mineral contained. They very much resemble those in the altered impure limestones round the Shap granite, and like them are polysynthetic and show a good deal of birefraction. They are, however, here not so often well- defined crystals, but more irregular grains and patches. They are often very much cracked, the cracks being infilled with chlorite and other substances. They occur irregularly, some parts of the rock being free from them and others containing swarms of small grains and crystals. In some specimens idocrase occurs with the garnet, some of it as good large, well-defined crystals on which characteristic angles can be determined. It is nearly all quite fresh and good, and in every way of normal character. Both garnet and idocrase crystals may be seen containing large numbers of small crystals of spinel, the garnet much more so than 80 Helin Ha chings== Rocksloy Grea Waves am the idocrase. No spinels are seen except as enclosures in those two minerals. The greater portion of them are of a good deep-green colour, and exactly resemble those seen in altered limestone of bombs from Somma; there are also colourless and pale reddish- brown crystals. If we take several thin sections of specimens from this occurrence and average, as it were, the results of microscopic examination, we find that a large proportion of the rock consists again of a base or groundmass, which varies greatly in its texture and fineness of grain. Sometimes it is a close-grained, felsitic-looking mass, quite cryptocrystalline, and nothing definite can be made out as to its component minerals. At other parts it becomes coarser, and examination with high powers seems to show that much of it is quartz and felspar; this conclusion being confirmed when we come upon good-sized patches, like glassy spots in ordinary light, which with crossed nicols are seen to consist of well-twinned felspar with sometimes more or less quartz, ‘This groundmass may be described as a calcareous adinole. In it are bedded many new minerals besides garnet and idocrase. Wollastonite occurs at some parts in considerable abundance, mainly as radiating sheaves and bunches, with sphene, epidote, and recrystallized calcite. In some slides are well-developed chloritic “spots,” as well as others of the pale yellow-green, almost quite isotropic, granular matter; and there are some which appear to be cordierite in early stages of development, corresponding exactly with similar spots seen to occur together with undoubted cordierite in other contact-rocks. A large hand-specimen of this rock from Falcon Clints I have analyzed. It contains :— Silica Bite 206 bon 900 209 53°80 per cent. Alumina ... ue 600 ak soo 20°25 Pe Ferric Oxide ane sits sine or 8°15 ia Lime see BOO 0 Be ais 3:27 AN Magnesia ... 600 500 000 ace 3°02 a Potashieeges. aes Bes ath aes 2°32 Nees Soda ek ee ate Ana ado 6°54 i {8 Be Water and Carbonic Acid ainsi base eit 2°90 50 100°25 Another occurrence of a similar calcareous adinole is found at Sneblazes. A thin section shows the same sort of groundmass. No garnets or idocrase appear in the specimen examined, but there is a good deal of augite in small crystals, and felspar is again seen here and there. ‘The analysis of this rock gives :— Silica a6 oc Bae as ie 50°60 per cent. Alumina es odd 4 coe 20°38 Ae Ferric Oxide ah oot 8°30 “ Lime ae oe ae T:79d i Magnesia ... : 2°58 i Potash 2°39 6 6-75 Soda see Mili 136 ae \ f Water and Carbonic Acid 3°80 W. M. Hutchings—Rocks of Great Whin Sill. 81 Another specimen of a like nature, from close to contact, near to Crag Lough, Bardon Mill, has the following composition :— Silica of O00 bic abe 609 48°20 per cent. -Alumina ... ase a se Ae 17°30 Fe Ferric Oxide See HR sais Boe 12°50 3 Lime Bs Ae ses ohh ah 10:08 as Magnesia ... ee aus shi des PRAT / 30 ORS ooo bbe aes ae Se 1:93 Pe Sats eRe Cte ih PE) iia js a Water and Carbonic Acid isi sie 4:05 Bs 100°82 It resembles the others in general composition, but shows hornblende among its new minerals. It now remains to consider the sandstones, of which a large number have been collected from different points. There is not very much to be said about them, because when they are pure, or nearly so, the alteration is limited to a compacting and conversion of them more or less into quartzites; and where they are less pure, the interstitial matter has undergone the same alterations as have been above described. Thus, where there has been any noticeable amount of argillaceous deposit with the quartz-grains, it is now often seen to consist largely of the same mixture of new white mica and chloritic matter; and in this way we pass back again towards altered sandy shales, as the interstitial constituents increase. It is noticeable, however, that whereas among the altered shales it is but seldom that brown mica is seen as a contact-mineral, and then only to a very subordinate degree, we find it more frequently and much more plentifully among the argillaceous sandstones. In one case from Rumbling Churn, near Dunstanburgh, there is as large a development of this biotite as might occur at any granite- contact, and all the characteristics of the mineral are the same. In previous allusions to the contact rocks of the Whin Sill (Guou. Maa., April, 1895) I had occasion to refer to the interesting question of the supposed transfer of soda from the igneous rock to the altered shales, etc., in such cases of basic intrusions. I pointed out that observers of the contact-effects of such rocks elsewhere had been forced to come to the conclusion that such a transfer does often take place, a very considerable mass of chemical and other evidence rendering any other verdict difficult, or even impossible. Most of our knowledge on this point comes to us from German petrologists, though instances of altered rocks rich in soda are not lacking in this country. When I commenced working at the petrology of the Whin Sill contact I naturally gave attention to this very important point, and it so happened that some of my first analyses, and separate determinations of alkalies in altered shales, very strongly confirmed the views expressed by the German authorities. In the course of the work I have made a considerable number of further determina- tions, the general result being that the answer obtained is not at all uniform in its direction. There are many of the shales in which soda DECADE IV.—VOL. V.—NO. II. 6 82 Notices of Memoirs—Dr. G.F. Matthew—Cambrian Genera. has increased very considerably ; but there are also plenty of others in which this is not the case, even with highly altered rocks close to the contact, the normal excess of potash over soda having remained undisturbed ; and the evidence, as will be seen, is rendered all the more contradictory by the fact that in a given vertical section of beds we may have a rock quite near the Whin, showing this chemically unchanged condition, whilst another one, further away from contact, shows a great increase of soda relatively to the potash. As previously pointed out, the rocks along the Whin Sill are not specially favourable for the study of the chemical aspect of the metamorphism, inasmuch as the igneous mass is intruded parallel to their strike, and we cannot take any one bed at a distance and follow it gradually up to the contact. All we are able to do is to rely on the fact that, apparently without any exception, the normal shales of the Carboniferous show an excess of potash over soda within certain limits. All the trustworthy chemical evidence available shows this to be the case, and I have myself confirmed it by large numbers of careful determinations, published and unpublished, on specimens from various localities; the two latest being a fireclay and a shale which I took from the neighbourhood of Bardon Mill, near to the exposure of the Whin Sill and its contact-rocks, but quite outside the area of its metamorphic action. The alkalies contained are respectively :— Potash... 900 500 2°62 per cent. and 2°66 per cent. Soda mt se 500 0:98 st and 1°24 a The three analyses given above of calcareous adinoles are all striking instances of a large increase in soda. The total, alkali-contents are all three high, though not higher than may be seen in some cases of chemically normal shales. But soda far exceeds potash in all of them. No shales of similar composition exist outside the contact- zone, and however we may explain the transfer of soda, we cannot very well deny its occurrence. This increase of soda, as a chemical fact, is accompanied by the mineralogical fact of the appearance _ of albite in the altered rock. Had we these cases only before us, there would not seem to be much difficulty in accepting the statements of previous observers on the subject. (Lo be continued.) INKS) ARIK OIHS, Oa IME sens SS). J.—Some CHaAracTEristic GENERA OF THE CAmpBrian.’ By G. F. Marrnew, LL.D., D.Sc., F.R.S.C. HE paper gives in brief the history and use of several generic - names, and the distribution of certain species to which they have been applied. These genera have an important bearing on the antiquity of the Olenellus Fauna. Bathyuriscus, Meek, known as a Middle Cambrian genus in Montana and Nevada, occurs in the © Olenellus Fauna of Kastern North America. It is nearly allied 1 Paper read in Section C (Geology), British Association, Toronto, August, 1897. Notices of Memoirs— Dr, Ells—Problems in Quebec Geology. 83 to the following genus—Dolichometopus, Angelin, of the Upper Paradowides Beds of Sweden, and is found in beds of similar age in Hastern Canada. With it is associated Dorypyge, Dames (= Olenoides in part of Walcott), which is a Middle Cambrian genus in Montana and is found also in the Olenellus Fauna of Eastern North America. Microdiscus, a genus of small trilobites, extending in Hastern Canada up to the Upper Paradoaides Beds, is found in the Olenellus Fauna. Agnostus has a peculiar development in the Upper Paradowides Beds in the appearance at that horizon of the section Levigati; the Brevifrontes also abound there. These two sections appear to be present in the fauna with Olenellus. If we accept the view that there has been a regular development of the faunas through Cambrian time, it is difficult to understand how Olenellus can be at the base of the Cambrian succession and yet found in company with so many genera and subgenera which are known members of the Middle Cambrian fauna, or that of the Upper Paradoxides Beds. Olenellus has not yet been found below the Paradoxides Beds, and the evidence adduced indicates that it ex- tended above rather than below this part of the Cambrian system. Ii.—Prositems in Quesec Grotocy.’ By R. W. Ents, LL.D., F.R.S.C., of the Geographical Survey of Canada. fY\HIS paper is a brief review of the geological work done in the province of Quebec since the appearance of Dr. Bigsby’s first paper on the geology of the province in 1827. It contains a short statement of the conclusions arrived at from time to time by the various workers in this field regarding the structure of the rock formations east of the St. Lawrence, as well as of the Laurentian complex to the north of that river. A summary of the latest views reached from the detailed study of these areas during the last fifteen years, which has appeared in the last volume of the Geological Survey’s Report, is also presented. In regard to the structure of the older crystallines north of the St. Lawrence and Ottawa rivers, it may be said that the opinion once held, that these rocks were originally of sedimentary origin, has now been greatly modified. The Laurentian rocks of Logan are now divided into two great groups. Of these, the lower is essentially a gneiss formation, and may be styled, for the sake of distinction, the Fundamental Gneiss. This is clearly older in point of time than the series of crystalline limestones, quartzose grey gneisses, and quartzite with which they are often so intimately associated as to render the determination of their true relations in the field difficult, but which at other points are clearly situated above the lower gneiss formation. These newer gneisses and limestones, which have been styled by Logan the “‘ Grenville Series,” are, without doubt, for the most part of sedimentary origin, though they are invaded in all directions by masses of granite, greenstone, and other forms of igneous rock. As for the Fundamental Gneiss, also once supposed to be largely of ? Abstract of paper read in Section C (Geology), British Association, Toronto, 1897. 84 Notices of Memoirs—Dr. Elis—Problems in Quebec Geology. sedimentary origin, it has been very conclusively demonstrated, chiefly through the agency of the microscope, that this is for the most part at least an altered igneous rock, and that the supposed bedding planes owe their existence to other causes than those of sedimentation. The original Upper Laurentian division, which included the great area of the Anorthosite rocks, also supposed at one time to represent altered sedimentary deposits, has been removed from the position it once occupied, since it has been proved, both by the evidence in the field and in the laboratory, to be of igneous origin and subsequent: to the deposition of the limestone and quartzite series with which it is associated, so that the Grenville Series, according to the earlier view as to the succession of strata, may now be taken to represent the upper portion of the Laurentian system. It may also be assumed to represent the lowest division of the clastic or sedimentary rocks in Canada. The relations of these to the rocks which have been styled the “Hastings Series” in Ontario are such that they may, in part at least, be regarded as portions of the same series which have been described in different portions of the field under different names; but whether these be regarded as belonging to the Laurentian or Huronian systems, is of small moment so long as their true relationship to each other and to the underlying Fundamental Gneiss is clearly understood. To the east of the St. Lawrence the old dispute as to the age of the fossiliferous rocks near the city of Quebec, as well as of their relations to the crystalline schists of the mountain area in the interior of the province, may now be considered as satisfactorily settled. The former hypothesis by which the crystalline schists were regarded as the equivalents, in point of time, of the fossiliferous sediments of the St. Lawrence Valley has been clearly shown to be unfounded, and the schists of the Sutton Mountain area are now assigned to the Huronian system, or are at least beneath the lowest Cambrian of the district. The relative position of the several divisions of the fossiliferous Quebec group has also been ascertained, and it is now established that the Sillery division is situated stratigraphically beneath the Levis, instead of being, as was at one time supposed, above it. As regards the age of the several divisions of the Quebec group (fossiliferous), it may be said that the Lévis is the apparent equivalent of the Calciferous formation, and that in its upper portion it approaches the Chazy ; while the upper portion of the Sillery is the apparent equivalent of the Potsdam Sandstone formation. Between the upper Sillery and the great mass of the rocks which have been referred to this division, there is a fault of considerable magnitude, so that the ~ lower portion of the Sillery presumably includes rocks which have been elsewhere classed as Cambrian, and these may extend as low as the Paradowxides zone or division of that system. The areas of black slate and limestone, which, in the General — Report for 1863, were regarded as beneath the crystalline schists and referable to the Potsdam formation, have been determined, on Reviews— Geological Survey of Scotland—Geology of Cowal. 895 the evidence of the contained fossils, to be much newer, and to be in fact the equivalents of the lower portion of the Trenton formation ; and to this horizon may also now be assigned the greater portion of the strata in the city of Quebec. Here, however, there are a number of anticlinal folds, and the presence of certain fossils, similar to those obtained from the Lévis beds, indicates that along some of these folds beds of that horizon may be found. The same age may be assigned to the great extension of the black slates and limestones which occur at intervals along the south shore of the St. Lawrence, nearly to the extremity of the Gaspé Peninsula, and which appear to dip beneath the strata of the Sillery formation at many points. 3 In regard to the use of the term Potsdam a distinction must now be made between the Potsdam formation and the Potsdam Sand- stone. The latter has been clearly proved in Canada to be the lower portion of the Calciferous formation, and is not separable from it, while there is a manifest break between this and the lower beds, or the Cambrian proper. The term Potsdam formation in Canadian geology was a comprehensive one like the term Cambrian, and like it included all between the Calciferous formation and the Huronian. The discriminate use of the terms has led to much confusion, and as the divisions of the Cambrian have now been properly determined the expression Potsdam formation has practi- cally no meaning in Canadian geology. 35) Jen We abana Se sual Sa. Memoirs oF THE GrotocicaL Survey, Scottanp: Tur GEroLocy or Cowat, including the part of Argyllshire between the Clyde and Loch Fine. By W. Gunn, F.G.S., C. T. Croues, M.A., F.G.S., and J. B. Hitz, R.N.; with Petrological Notes by J. J. H. Teatt, M.A., F.R.S., Sec.G.S., and Dr. Hatcu, Ph.D., F.G.S. 8vo; pp. 333, with index, numerous illustrations in the text, and 10 plates. (Edinburgh: Neill & Co. Price 6s.) ee Director-General of the Geological Survey observes, in his Preface to this Memoir, that the district known as Cowal “embraces the south-western extension of the various bands of metamorphic rocks which form the southern edge of the Highlands. Bounded on three sides by coast-lines, and penetrated by a number of sea-lochs, it affords better and more continuous sections of these rocks than are generally to be met with in the interior of the country. . . . . From the detailed study of this part of the Highlands much information has been obtained by the Geological Survey regarding the structures of the schists and the successive movements by which these structures have been produced. Originally most of the rocks described in the following chapters formed a thick series of sedimentary deposits, the geological age of which still remains to be determined. These strata have been found to have undergone a remarkable series of repeated movements. After being thrown into folds and having been cleaved so as to acquire a first 86 Reviews— Geological Survey of Scotland— system of deformation, they have again suffered a repetition of the process more than once. They consequently represent secondary and tertiary, perhaps even quaternary, structures, probably due to mechanical movements with accompanying recrystallization. The regional metamorphism thus produced is not uniformly distributed, but seems to increase in intensity both from the south-east and north-west towards a nearly central line, ranging about north-east — and south-west, which is an anticline of the foliation. It has not been traced to any intrusion of igneous rock, and is so general and diffused that it can hardly be regarded as in any sense a contact phenomenon. Where intrusive masses occur in the district they have given rise to their own accompanying alteration, quite apart from the general metamorphism of the whole area. These in- teresting and complicated structures, so well displayed in Cowal, are fully discussed in the present Memoir.” The Director-General further observes that “ Mr. Clough, having mapped by far the largest part of the whole district, has had general charge of the Memoir, which is mainly written by him.” The extreme length of the district in question, from Ardlamont Point on the south-west to the granite edge in a north-easterly direction, is about 44 miles; with a breadth of about 18 miles from Toward Point on the Firth of Clyde to Otter Beacon on Loch Fine. The country is mountainous, though the elevations nowhere quite | attain 8,000 feet, and may be said to decrease rather uniformly towards tke south-west. By far the larger portion of the area is occupied by metamorphic rocks. Subjoined is a list of these, not to be regarded as representing a stratigraphical sequence. ScCHISTS PROBABLY OF SEDIMENTARY ORIGIN : — Phylhtes, including the two series of Dunoon and Ardrishaig, which consist of phyllites and thin limestones, mixed in the first series with schistose grits and in the second with quartzite schists. Schistose grits and greywackes. Quartzite schist or quartz schist. Albite schist. Garnetiferous mica schist. Graphite schist. Schistose limestones on various 1s horizons, including the Loch Tay limestone. Mica schist. Areas coloured thus in the maps may also include unseparated albite schists, sheared grits and greywackes, and phyllites. Green beds: chlorite- epidote schists. The group lines may include some mica schists and schistose greywackes. Tenzous Rocks :— Epidiorites, hornblende and chlorite schists, serpentine. Besides the above a number of unfoliated igneous rocks occur intrusive in the schists. The age of the schists, even in relation to each other, is not certainly known, but the different bands are seen to traverse the region in a north-east and south-west direction. The intimate structure of the rocks is described with much detail. Amongst the physical features of the more quartzose beds may be noted the occurrence of - pebbles, mainly of quartz, felspar, or clay-slate. These pebbles have been subjected to a stretching action, which is supposed to have The Geology of Cowal. 87 taken place at the time of the production of the streakiness seen on the foliation planes of the adjoining phyllites, and probably both were accompaniments of the production of foliation. The elongation seems comparable to the distortion of fossils on the cleavage planes of slate. The behaviour of the several groups towards the great central anticline of foliation presents some very interesting features. ‘ In ‘the anticline’ folds (says Mr. Clough) with axes hading north- west, it is the under limbs of anticlines that have a tendency to be most thinned, whether we are on the south-east or north-west side of the centre of the anticline. Hence, if we regard the early ‘ pre- anticline’ folds as having originally had axes hading north-west, the same law of the greater thinning of under limbs of anticlines prevails in both; and we may conclude that thé source of the pressure which produced them both lay to the north-west of the area being described, and that the pressure was outwards from the Highlands in a south-east direction. The evidence in the north-west of Scot- land is now well known to show that there were there, partly at all events in Post-Cambrian times, mountain-making forces pressing outwards from the Highlands in a W.N.W. direction. Hence the central Highlands represent an area from which earth-moving forces have pressed outwards, on the one side in a west-north-westerly and on the other side in a south-easterly direction.” The bulk of the schists are regarded as probably of sedimentary origin. Chapters iii and iv are devoted to a detailed description of them. The albite schists present some curious features. They occur mainly towards the anticline centre, and at Lochgoilhead all the more micaceous schists contain albites. The albite spots are almost confined to the micaceous and chloritic beds, and it is doubtful whether they occur at all in the more quartzose pebbly beds. It is inferred from their never showing any appearance of stretching that the albites are of later age than the mass of the movements affecting the rocks in which they occur. The “Green Beds” present another curious group of rocks. These are of a mixed and variable character; for on the north- west side of the anticline about one-half of the group consists of other schists, whilst on the south-east side the different outcrops are comparatively unmixed. They are described for the most part as epidote-chlorite schists, and are often intersected by thin quartzose veins coloured green by epidote [? the ‘“‘epidosite”’ of Sterry Hunt]. Of the schistose igneous rocks, the epidiorites, hornblende schists, and related chlorite schists, associated with the presumed sedimentary series, are most abundant towards the side of Loch Fine. They are generally harder than the schists, and thus help in working out the physical structure. It is believed that they represent old intrusions rather than lava-flows. There is a special danger of con- fusing some of these old igneous rocks with the ‘“ green beds.” In the area between Stralachlan and Loch Fine, these epidiorites, etc., form huge irregular masses behaving on a large scale like sills with irregular protrusions, the longer axes of which coincide with the strike of the main mass, and of the quartzites in which they are 88 Reviews— Geological Survey of Scotland— intruded. Mr. Teall gives the following description of their ap- pearance under the microscope: ‘ Uralitic hornblende, a saussuritic aggregate of water-clear felspar and granular epidote, irregular patches of sphene (leucoxene) and aggregates of chlorite.” In chapter vii the minerals of the schists are enumerated and partly described, whilst much attention is paid to the direction of stretching. Chapter viii is devoted to the general physical structure of the schists, together with remarks on metamorphism. The most conspicuous feature of the schist area, as may be inferred from previous remarks, is the great anticline of foliation running in a direction about 35° W. of S. through the heads of Loch Goil, Loch Striven, and Loch Riddon, and the hills about a mile north-west of Tighnabruaich. There is no doubt that this anticline is a true arch of an early foliation; but scarcely perhaps an anticline of bedding. The authors (and more especially Mr. Clough) apparently conclude, after much weighing of the evidence, that at least five of the groups on the north-west side of the anticline are unrepresented on the south- east side, notwithstanding some apparent points of resemblance. Lines of actual rupture contemporaneous with the schist-making, comparable to the “thrusts” of the north-west of Scotland, probably do not occur anywhere in Cowal, except on the smallest scale, such as strain-slips with throws not exceeding a few inches. The numerous faults which have been mapped and which have effective . throws, are all later than the schist-making, and break up the minerals and planes of schistosity instead of helping to form them. To the question regarding the agents which produced the general metamorphism of the district, Mr. Clough considers that it would be premature to reply; but he does not consider that there is any exposure of igneous rock which would account for it. The alteration effected by the Glen Fine granite, for instance, does not extend for more than a mile, and is of quite a different character. The direction of the boundary fault between the Schists and the Old Red Sandstone is nearly parallel to that of the centre of the anticline. This fault cuts off a shred of Upper Old Red Sandstone rocks, which thus appear at the extremity of the peninsula that terminates in Toward Point. They consist, in the main, of red breccias and sandstones mixed with occasional blood-red and variegated shales; calcareous sandstones and magnesian limestones are numerous on a certain horizon. One of the sections which best illustrates the relations between the red marls and the metamorphic schists occurs on the shore just to the south of Inellan pier. Chapters x to xiv are devoted to the igneous rocks (unfoliated). A small part of the igneous complex of Garabhal Hill, ete., comes within the district. These are, in fact, granitites with a tendency to pass into a coarse dioritic rock; the granitic rocks are generally characterized by abundant porphyritic crystais of orthoclase felspar. Considerable attention is paid to the character of the metamorphism near the edge of the plutonic rock, chiefly with a view to contrast - the metamorphism special to its neighbourhood with that further away near the anticline of Cowal. The Geology of Cowal. 89 Hornblende-porphyrites and felsites are classed together, since the Same porphyritic constituents, viz., felspar, black mica or chlorite, sometimes hornblende, and scattered quartz blebs, occur in both. These rocks behave in the field in the same way as the lamprophyres (presently to be mentioned), generally forming sheets which run roughly with the foliation of the schists; they are of limited extent. An intrusive boss of some importance is also described as hyperite, the rock consisting of hypersthene, augite (diallagic in part), plagioclase (more or less lath-shaped), iron-ores, and interstitial quartz. Of the older igneous rocks are those described under the terms lamprophyre and mica-trap. It is only when the mica is macroscopically prominent that the latter term seems applicable. By a gradual decrease in the amount of mica the mica-dolerites may pass into rocks of more normal doleritic aspect. In all these early dolerites which have been examined the augite differs from that of the Tertiary basalts in belonging to the pale form, malacolite, and for the most part occurring porphyritically. In the north and east of Cowal these lamprophyres are exceedingly numerous, but they are not known within a distance of four or five miles of the Upper Old Red Sandstone boundary. They rarely form vertical dykes; when they do so, these dykes usually run in a different direction _ to that of the basalts. Most frequently they occur as sheets with varying and not very steep hades to the horizon. They do not keep to the bedding or foliation of the schists, but may be constantly seen cutting across their crumplings. It is evident that all the move- ments in connection with the foliation of the schist had ceased before their intrusion. Though thin and inconstant, the lamprophyres are of considerable interest in working out the geological structure of the district, and a greater help than the basalts. This is because the majority of the faults are of later date than the lamprophyres, and throw them, so that they help to indicate the different faults and even the amount of their respective throws, independently of the schists. An inspection of the geological map will show that parts of Cowal are seamed by basaltic dykes: this subject is very fully treated in the Memoir. Basalts, dolerites, and tachylites constitute the group, with which even augite-andesites are included. Thin margins or selvages of distinctly glassy rock, tachylite, are common, but not to be found without close search. One of the most curious features of basaltic dykes, especially noticeable on the coast, is the tendency for some to weather in relief, whilst others form recesses sometimes hollowed out into caves. The authors consider that the size of the grain is often a determining factor in these cases. The intimate structure of the basaltic rocks is treated of at considerable length. With respect to the relative age of the dykes, the broad east-and- west dykes are regarded as older than the basalts having a north- west direction. ‘If we suppose the early east-and-west dykes to be of Carboniferous age, the interval of time between them and the north-west dykes must be immense; for there can be no doubt that many of the latter belong to the same set as those which, still with a north-west direction, are seen in the island of Mull to intersect 90 Reviews— Geological Survey of Scotland—Geology of Cowal. the bedded basalts of Tertiary age.” The very conspicuous east-and- west dykes at Ardlamont Point are not crossed by any running north and south; but, since these are regarded as continuations of the two large dykes crossing the island of Bute, where one of them is clearly cut by later Tertiary dykes, we may infer that the Ardlamont dykes are of earlier date than the Tertiary period. Similar con- clusions result from the detailed examination of other districts. Within this area only five intrusions have been recognized as trachyte: these are all dykes, which are considered to be later than the basalts. Three chapters are devoted to the general geological structure of particular districts, and the numerous sections given in the text are of great service to the readers in this connection. The structure of the country about Lochgoilhead, for instance, is particularly interesting on account of its proximity to the anticline. Moreover, since the much frequented coach-road through Hell’s Glen traverses this region, it enjoys the advantage of being easily accessible. Two chapters, illustrated by a special map (Clough), are devoted to Glacial deposits. The following features are indicated in the map :— (1) Landslips; (2) marine and fresh-water alluvia and peat in basin- shaped hollows; (8) boulder-clay and sandy drift without definite moraine shapes; (4) drift with well-defined moraines. The direction of the striz ranges from §.W. through §. to 8.E., with few exceptions. The remaining chapters deal with such subjects as marine and fresh-water allan. peat, landslips, blown sand, prehistoric¢ HOUT geological aspects of the scenery, and economic resources. In the appendix Mr. Teall makes some general remarks on ihe petrography of the district. After insisting on the well-known fact that, in a complex series of stratified deposits, the coarser-grained sediments retain traces of their original character long after all such traces have disappeared from the finer-grained deposits, he proceeds to illustrate the point with reference to the gneissose grits (the schistose grits and greywackes of the Memoir) so largely developed in the Southern Highlands. Although distinctly gneissose in structure and composition, they differ markedly from igneous _ gneisses in their relation to the other rocks with which they are associated, and frequently contain relics of original grains of quartz, often bluish in colour, and felspar. The rocks of this class are crystalline schists essentially composed of quartz, felspar, and one or two micas: they are therefore gneisses in the usual sense of the term. Where conspicuous traces of their clastic origin remain they may be termed gneissose grits; when all, or nearly all, such traces have disappeared they may be termed granulitic gneisses: they pass by insensible gradations into felspathic mica schists. ; Plates i to v are reproductions of photographs of Natural Rock — Exposures, taken by Mr. R. Lunn. The Geological Survey of Scotland is to be congratulated on these most effective pictures of contortion, which are at once instructive and picturesque. ‘The other plates are _ likewise very good of their kind, and the volume generally may be deemed a most satisfactory contribution to geological literature. Reports and Proceedings—Geological Society of London. 91 seven @iev ae Se AlN») eer @ Cr ban GS GroLoaicaL Society oF Lonpon. I.—December 15, 1897.—Dr. Henry Hicks, F.R.S., President, in the Chair. The following communications were read :— 1. “On the Pyromerides of Boulay Bay, Jersey.” By John Parkinson, Hsq., ¥.G.S. After briefly noticing the literature of the subject, the author describes the altered rhyolites of Boulay Bay. One variety, the commonest, is of a dark-red colour, showing flow-structure ; another is porphyritic; a third, near the centre ‘of the Bay, has a pale- greenish matrix enclosing fragments, which, however, are due to flow-brecciation. Large “pyromerides occur in two localities; in the more interesting, ‘that north of the jetty, the structure of the rock indicates either a very peculiar magmatic differentiation in siti or (more probably) the mixture of two magmas differing in their stage of consolidation. From study of a series of specimens of the pyromeridal rock, the author arrives at the following conclusions :—(1) The rock shows marked flow-structure and at times bands which indicate a slight difference in its composition, the latter tending to assume a monili- form outline. In such the microscopic structure corresponds with that of the pyromerides, and exhibits traces of radial crystallization. (2) These afford a passage into somewhat oval pyromerides, with rather tapering ends and irregularly mammillated surfaces. (3) From these sometimes a single one seems to be thrown off, while lines of pyromerides or little lumps of similar material are scattered about the matrix. (4) Many of the pyromerides are solid throughout ; others have a central cavity filled with quartz. The author describes varieties of the pyromerides. They are generally deep-red in colour, and exhibit (a) fluxion-structure, made more distinct by minute black microliths; (b) a radial structure ; (c) a “patchy” devitrified structure (with crossed nicols) ;—the second (b) being not always present. The matrix is usually of a greenish tint, showing devitrification-structure and sometimes a trace of perlitic structure. The pyromerides frequently exhibit more or less crescentic cracks, due apparently to contraction, which have been filled by quartz. Sometimes also they scale off in rudely crescentic shells. In one locality a variety with good spherulites, about as large as a pea, passes into one showing a fluxion-structure and pyromerides, having traces of radial structure as well as clots and irregular ‘ wisps,” suggestive of a stiffer material broken up by one more liquid. ‘As the result of his studies, the author thinks that while very regular spherulites do occur, apparently in consequence of radial erystallization round a centre, the pyromerides are due to the mixture of two magmas slightly different in composition and fluidity, the less plastic of the two being sometimes drawn out into streaks, but at others forming lumps, in which, where their form is suitable, a radial 92 Reports and Proceedings—Geological Society of London. structure is subsequently developed. He concludes by comparing the pyromerides of Boulay Bay with specimens from other localities described by MM. Delesse and Lévy, Professor Iddings, and Miss Raisin, or collected by himself, and by discussing the quartz-filled cavities which occur in certain cases. ‘These he regards as originally vesicles, and not due to any subsequent decomposition. 2. “On the Exploration of Ty Newydd Cave near Tremeirchion, ~ North Wales.” By the Rev. G. C. H. Pollen, 8.J., F.G.S. In November, 1896, a Committee was formed, consisting of Dr. H. Hicks, Dr. H. Woodward, and the author, for the purpose of exploring this cavern, which is situated in the same ravine on the east side of the Vale of Clwyd as the well-known caverns of Ffynnon Beuno and Cae Gwyn, explored about twelve years ago by Dr. H. Hicks and Mr. H. B. Luxmoore. Grants have been made by the Royal Society and by the Government Grant Committee for the purpose of carrying on the explorations ; and though a considerable time must elapse before the work is completed, the results already obtained are of so much importance that the author has thought it advisable to bring them before the Society. In the work of exploration he has throughout been ably assisted by the theological students of St. Beuno’s College. The cavern had been in part broken into by quarrying operations, but the chambers and tunnels were completely filled up with more or less stratified deposits, and had remained entirely untouched. Although the ground above the cavern is strewn over with drift and erratics from the North and from the central areas of Wales, not a fragment of anything but immediately local material has been discovered in the cavern itself, showing clearly that the deposits in the cavern had been carried in by water before the Northern and Western ice had reached this area. ‘he work has been carried on almost continuously throughout the year, and most of the material has been removed for a distance of over 60 feet from the entrance. The height of the cavern above sea-level is 420 feet, or about 20 feet above the floor of the Cae Gwyn Cave. The following points appear to the author to be now fully established :— (1) The material in the Ty Newydd Cave, as in the lower parts of those of Ffynnon Beuno and Cae Gwyn, is of purely local origin. Of this he can speak with confidence, as the question was betore him from the beginning, and the gravels were examined with minute care for erratics. (2) This local deposit is of earlier date than the Boulder-clay with Western and Northern Drift. This was proved by the finding of granite- and felsite-boulders abundantly at higher levels and over the cave, and in one case filling the upper part of one of the fissures communicating from above with the cavern. (3) The occurrence of the tooth of a large mammal (Rhinoceros) _ in the lower part of the cave shows that the animal was con- temporary with, or of earlier date than, the infilling of the cavern by the local dritt. Reports and Proceedings—Geological Society of London. 93 IJ.—January 5, 1898.—Dr. Henry Hicks, F.R.S., President, in the Chair. Professor Judd drew attention to the outline geological maps of England and Wales on the scale of 80 miles to the inch, for the use of schools and colleges, presented by John Lloyd, Esq. These were reproduced, by permission of the Science and Art Department, from the maps in use at the Royal College of Science, South Kensington. The following communications were read :— 1. “On the Structure of the Davos Valley.” By A. Vaughan Jennings, Hsq., F.L.S., F.G.S. Hvidence is brought forward to show that the level area, about four miles in length, near Davos is occupied by superficial deposits, and that the lateral talus-fans there have been cut through at a relatively recent date since their accumulation ; that the northern end towards Wolfgang is blocked by moraine-material of great thickness, but for which the Davoser See would drain north to the Landquart, carrying with it the waters of the Fluela and Dischma ; that the contour-lines suggest the former existence of a far larger lake stretching south towards Frauenkirch, and that in that part there is proof of the previous existence of a great detrital fan sufficient to account for the existence of the lake in question. It is shown that the former ice-movement was not from the present watershed between the tributaries of the Landwasser and Landquart, but from a spot farther south. The author concludes that the main valley-systems were marked out in Pre-Glacial times, and that at one time there was a water- shed somewhere between Davos Platz and Frauenkirch. During the Glacial Period moraine-material was heaped up across the valley below the Hornli, and held up the waters to the south, forming a great lake of which the present Davoser See is a relic, the outflow being probably over a low saddle near the present Wolfgang ; during this time a great moraine and detrital fan existed across the valley to the south, and the lake for a long time was thus prevented from draining in that direction. After the Glacial Period the northern moraine was subjected to little erosion, but the southern one, formed from the first of looser material, was rapidly cut back by the Sertig Bach, and in time the barrier was so weakened as to cause that end of the lake to be tapped, and at that time the terraces opposite Frauenkirch may have been levelled, while the flow over Wolfgang would be stopped, and the Fluela and Dischma streams turned southward ; the Landquart would then cut away the margins of the talus-fans which had been accumulating in the lake. 2. “Sections along the Lancashire, Derbyshire, and Hast Coast Railway between Lincoln and Chesterfield.” By C. Fox-Strangways, Hsq., F.G.S. (Communicated by permission of the Director-General of H.M. Geological Survey.) The portion of the line considered in this paper occupies a distance of about forty miles, and runs nearly at right angles to the strike of all the beds from the Lias to the Coal-measures. 94 | Obituary—G. H. Piper, F.G.S. The lower part of the Lias and the Rhetic beds are entirely con- cealed; but grey marls overlying red marls occur about half a mile east of Clifton Station, and at the station the Red Marl of the Keuper comes on in force. The alluvial deposits of the Trent, pierced to a depth of from 25 to 30 feet, consist principally of loam overlying varying thicknesses of sand and gravel. Horns of red deer were found at a depth of 25 feet. At Dukeries Station white flaggy Keuper sandstones appear from beneath the Red Marl, and probably represent the eastward extension of the Tuxford Stone. A deep well here has been bored to a depth of 644 feet from the present surface, and details of the section are given in the paper. South of Kirton there is a deep cutting in the Waterstones, and after leaving the escarpment the line enters on the great dip-slope of the Bunter Pebble Beds, which are shown at Ollerton and at intervals for four miles beyond this. There are no sections in the Lower Red and Mottled Sandstones ; and west of Warsop the line crosses the dip- slope of the Magnesian Limestone. Details of the sections in this rock are given. Between Scarcliff and Bolsover the line crosses the Permian escarpment in a tunnel, the whole of which is in the Coal-measures ; these are high up in the series, and contain no coal-seams of value. They are not stained red. West of Arkwright’s Town Station is a very complete section of - beds representing the Middle Coal and Ironstone series (the most valuable part of the Derbyshire Coalfield), of which full details are given, most of the important coal-seams being readily recognized ; and the author describes some remarkable features in the relation- ships of some of the sandstones to the other deposits. The absence of Glacial beds is of much interest; not a trace of genuine Boulder-clay has been seen along the whole line. (Qs SALA Ol INAS INS. GEORGES HARRY JER ERE sEaGrss Born Aprit 8, 1819. Dizp Aveust 26, 1897. Tur subject of this brief notice, the second son of the late Captain EH. J. Piper, R.N., was born in London in 1819, in the neighbourhood of Regent’s Park, where his family resided. His parents removed to Herefordshire in 1829, taking their son George, then a boy of ten years old, with them. Naturally an observant youth, country life and pursuits, after London, had a great attraction for him, and he speedily became interested in studying — the birds, trees, and flowers, and early learned to fish and shoot. When only fourteen, however, his health gave way, and he had to remain in bed for about three years, suffering from a lame leg, and was never entirely free from pain during the remainder of his life. - As a consequence of this, his education was carried on at home, in a more or less desultory manner. Nevertheless, he was a keen Obituary—G. H. Piper, F.G.S. 95 scholar, and at about eighteen years of age he was duly articled to the late Mr. Thomas Jones, Attorney of Ledbury ; and having served his master and duly passed his examinations in law, he was admitted as a Solicitor in 1849, and from that time commenced to practise in Ledbury, where he continued in his profession until his death. He was joined in partnership by Mr. C. HE. Lilley in 1886, and was one of the oldest solicitors in the county. In addition to his private practice he also held appointments as Commissioner to Administer Oaths, Perpetual Commissioner, etc., Deputy-Registrar, and in 1865 Registrar, of the County Court and High Bailiff of the Court, which offices he held up to the time of his death. . Mr. Piper took a keen interest in the progress and work of the Horticultural and Natural History Societies of the County of Hereford, and had filled the position of President both of the Woolhope Naturalists’ Field Club and the Malvern Naturalists’ Field Club. To these Societies he communicated many papers, and with them he did much excellent work in botany, local archeology, and geology, more especially in the latter field of research. Mr. Piper’s geological work was carried on for years in association with the late Rev. W. S. Symonds, M.A., F.G.S., of Pendock Rectory, Tewkesbury; Dr. Bull of Hereford; the Rev. P. B. Brodie, M.A., F.G.S., and other enthusiastic workers. The greatest geological achievement performed by Mr. Piper was the carrying out successfully, after many years of patient explora- tion, the complete examination and recording, foot by foot, of the famous section near the railway tunnel at Ledbury, comprising the series of deposits from the Aymestry Limestone, through the Upper _ Ludlow rocks ; the Downton Sandstone, with Péerygotus ; the Ledbury shales, consisting of red, grey, purple shales, and grey marl-beds, with Pteraspis, Auchenaspis, Cephalaspis, Onchus, Pterygotus, Lingula cornea, etc. ; followed by Lower Old Red Sandstone, with Pterygotus, Pieraspis, and Cephalaspis, ete. In Mr. Symonds’ paper ‘“‘On the Old Red of Herefordshire” he writes of the Passage-Beds at Ledbury: ‘“‘ Having again visited Ludlow, and compared the Passage-beds of that district with those of Ledbury, I am convinced that nowhere perhaps in the world is there such an exhibition of Passage-beds presented to the eye of the geologist as at the Ledbury Tunnel on the Worcester and Hereford Railway.” See H. Woodward’s “Brit. Foss. Crustacea” (Merostomata) : Pal. Soe., part ili, 1871, p. 99. The rich collection of fossils which Mr. Piper formed from the Ledbury Tunnel Section, and from other localities in the neighbour- hood, will, it is believed, shortly find a home in the British Museum (Natural History), Cromwell Road, where so many of his fine Cephalaspidian fishes have already been presented in past years, including the superb group of twelve individuals of Cephalaspis Murchisoni, preserved in one block of Old Red Sandstone— forming Plate x in Mr. Arthur Smith Woodward’s Catalogue of Fossil Fishes in the British Museum (Natural History), Part ii, 1891, p. 189— 96 Miscellaneous—Bibliographies. from the Passage-beds, Ledbury, presented by Mr. George H. Piper in 1889. Mr. Piper was elected a Fellow of the Geological Society of London in 1874, but his numerous scientific papers will mostly be found in the Transactions of the Woolhope Club. He was for many years local Hon. Secretary of the Royal Agri- cultural Benevolent Institution, and took a deep interest in all matters relating to agriculture, and especially the cultivation of fruit and — of roses. He largely assisted in the publication of ‘The Herefordshire Pomona,” and was with the late Dr. Bull selected to visit Normandy to inquire into the subject of fruit-culture there and to exhibit Herefordshire fruit. These gentlemen returned with several prizes awarded at the Rouen Exhibition for fruit grown in their own county. It would be impossible here to convey a just idea of the large and varied fields of scientific activity and social benevolence to which Mr. George Piper devoted his long and useful life; but the testimony of respect shown for him by his fellow-townsmen of all classes at his funeral might be cited as good evidence that he had not lived in vain. He was not only highly accomplished in many literary and scientific fields of inquiry, but ‘‘he was known to all as a genial, upright, and courteous gentleman, whose life was not spent for himself alone, but most largely for the good of others. In him the inhabitants of Ledbury and its neighbourhood have lost an able lawyer and a much respected friend.” (From Mr. F. Russell’s speech in Ledbury County Court.) IMEI S\SsIa IIL /AIN EHO OS ——— A BreriocGraPHuy oF NorroLk GLACIOLOGY, INCLUDING THE CROMER CLirrs, WITH THE Forest-BED SEeRrES. By W. Jerome Harrison, F.GS. (Reprinted from the Glacialists’ Magazine for March, June, and September, 1897.)—This work of 91 pages contains all the titles and brief abstracts of most of the papers dealing with the Cromer Forest-bed and the Glacial Drifts of Norfolk, published between 1745 and 1897. To workers on Hast-Anglian geology this will henceforth be an indispensable work of reference, and all will feel greatly indebted to Mr. Harrison for the labour and care bestowed on the work. Two years ago he prepared a similar work on Midland Glaciology. A Brptiocrapuy relating to the Geology, Paleontology, and Mineral Resources of California, has been compiled by Captain — Anthony W. Vogdes (California State Mining Bureau, Bulletin No. 10). This is arranged, not chronologically, but according to the several sources of publication ; there are some explanatory notes — and there is a good index. The list includes works published up to 1896. THE GHOLOGICAL MAGAZINE. NEW. SERIES. DECADE IVa »VOLW Vi No. III.—MARCH, 1898. ORTGINADL ARTICLIENS. 7.—Tue Farumst Hnaravep GeroLtocicAa, Mars or ENGLAND AND WALES. By Professor J. W. Jupp, C.B., LL.D., F.R.S., V.P.G.S., etc. N a previous article,’ a sketch has been given of what is known concerning the origin and history of the early manuscript maps of William Smith. I have shown that concerning these maps, though they were not published, in the technical sense of that term, there exists a satisfactory body of external evidence with regard to the period of their preparation, while they furnish in themselves abundant proofs that they must have been constructed at the dates inscribed upon them. These facts have been so generally recognized that—since the clear statements on the question which have been made by Fitton, Farey, Sedgwick, and Phillips—no one has ever thought of either questioning the antiquity of the maps or denying to William Smith the honour of being the first to construct a true geological map of England and Wales. But I find that, even with regard to the later maps and sections of William Smith, which were actually engraved and published, there still exists a certain amount of uncertainty. Maps have been publicly ascribed to Smith, with the preparation of which he certainly had nothing to do; while, on the other hand, some of the most important works issued by him have altogether failed to attract the attention which they deserve. Immediately after the preparation of the Manuscript Map of England and Wales in 1801, the question of its publication, on a larger scale, was seriously taken in hand by Smith and his friends. A prospectus dated Mitford, near Bath, June Ist, 1801, was prepared by William Smith, and extensively circulated by Debrett of Piccadilly (opposite to Burlington House), asking for subscribers to a work that was to be entitled ‘‘ Accurate Delineations and Descriptions of the Natural Order of the various Strata that are found in different parts of England and Wales, with Practical Observations thereon.” The author promised that this work should contain “a correct map of the strata, describing the general course 1 GrortocicaL Macazine, n.8., Dec. LY, Vol. IV (1897), p. 489. od DECADE IVY.—VOL. V.—NO. III. ( 98 Prof, Judd—The Earliest Engraved Geological Maps. and width of each stratum on the surface, accompanied by a general section, showing their proportion, dip, and direction; the map and sections, to make them more striking and just representations of nature, will be all given in the proper colours.” Smith’s friend Richardson urged that a Latin edition of the book should be issued with the English one, and it is certain that if this had been done, all possibility of contesting Smith’s claim to priority would have been destroyed. Unfortunately, however, the failure of the publisher Debrett, and the limited means and numerous business avocations of William Smith, prevented the realization of these projects. Thanks, however, to the splendid loyalty of Smith’s numerous friends—especially Richardson, Townsend, and Farey—there exists such a body of evidence concerning Smith’s discoveries and teaching, all published between the years 1801 and 1815, that no impartial judge can for one moment hesitate in assigning to Smith that priority so strenuously claimed for him by Fitton, Farey, Sedgwick, and Phillips. Nor can it be justly asserted that the treatment of Smith by his — contemporaries was other than generous and forbearing. In 1802 prizes of fifty guineas were offered by the Society of Arts for “mineralogical maps of either England, Scotland, or Ireland, on a scale of not less than 15 miles to the inch,” and the offer was renewed year by year down to 1814, when the prize for the English — Map was claimed by and awarded to William Smith. As Phillips remarked : ‘ At this moment, any map, however crude and incorrect, professing to be a mineralogical map of a part of the British Islands, would have been a source of lasting reputation to its editor; any account of the principal facts then ascertained near Bath would have been welcomed with admiration. Had Mr. Smith been exposed to this ungenerous rivalry, he must have sunk under the grief and vexation of being anticipated in his map by some inferior com- pilation, and in his other labours by notices which, in consequence of his wandering habits and laborious profession, it would have been more easy for others than himself to have drawn up. But nothing of this kind happened.” That a knowledge of William Smith’s ideas and discoveries had by this time become very widely diffused, not only in this country, but all over Europe, and even in America, there is abundant evidence. Manuscript copies of his original table of strata with their fossils had been widely circulated, and every facility had been given to those interested in the subject to make transcripts of the maps which were so freely exhibited by their author. At agricultural meetings of all kinds Smith was a constant attendant, exhibiting and lending his maps for inspection; while reports of his explanations of maps and sections not unfrequently found their way into the newspapers. At Trim Street in Bath, in the year 1802, and a little later near Charing Cross, London (Craven Street), a collection of maps and sections, _ with an illustrative series of fossils, was arranged, and exhibited freely to all who chose to call. This collection of fossils, which Prof. Judd—The Earliest Engraved Geological Maps. 99 after a fire at Craven Street in 1804 was removed to Buckingham Street, was purchased by the Trustees of the British Museum in 1816. It originally consisted of 2,657 specimens, belonging to 693 species, collected at 263 different British localities ; and such portions of it as can be identified have been brought together and arranged according to William Smith’s original plan in the British Museum (Natural History) at South Kensington, by the pious care of Dr. Henry Woodward. It must indeed be confessed that, between the years 1801 and 1815, not only did William Smith seem to act as though he were absolutely careless of his claims to priority as a geological investi- gator, but it is difficult to conceive how he could have adopted plans more calculated to give rise to controversy as to the validity of those claims. , In 1805 Smith’s large and detailed geological map of Somerset- shire was completed and publicly exhibited, and a project was started by Sir John Sinclair, the President of the Board of Agriculture, and Mr. Crawshay, a warm friend of Smith, to attach the great geological pioneer to the corps of Engineers then commencing the Ordnance Survey of the country: had this been done, the establishment of the English Geological Survey would have been antedated by no less than thirty years. But this project, as well as attempts made by Sir Joseph Banks and other friends to procure the publication of Smith’s map by subscription, were doomed to failure. Smith’s wandering life, his unfamiliarity with literary work, and his disinclination to engage in it, no less than the constant attraction of field-research, by which he was continually making additions and corrections in his maps, all conspired to render difficult the publication, in a worthy manner, of the great work which he had produced. In 1807 Greenough, with the aid of a few mineralogical friends, founded the Geological Society. By that date we are told that the idea of publishing Smith’s geological map was so generally recog- nized as having been abandoned, that, among the undertakings recommended to the infant society as especially worthy of its attention, was that of the compilation of a Geological Map of England and Wales. The idea was warmly espoused by the Society, and the work was entrusted to Greenough, by whom the task was commenced in 1808. It should always be borne in mind that this work of Greenough, though of great value in itself, was an undertaking of a totally different kind from that of William Smith. Smith was a great original discoverer and creator, and almost every entry on his map was the result of his own personal observation. Greenough, on the other hand, was essentially a clever and an industrious compiler. He received, from the first, valuable assistance from such men as De la Beche, Buddle, Farey, and other geologists; Aiken contributed a geological sketch of Shropshire, and Fryer one of the Lake District ; while Buckland and Conybeare both made valuable con- tributions to the work. Most important of all was the circumstance 100 Prof. Judd—The Earliest Engraved Geological Maps. that the actual engraving of his map was entrusted to a geologist who is second only to William Smith himself in his contributions to English stratigraphical geology. Thomas Webster, in his letters to Sir Henry Englefield, published in 1815, had shown that he had unravelled many of the complexities of the English Tertiary strata, and laid the foundation of a correct classification of the beds which underlie the Chalk in the South-East of England; and it was to Webster that we owe the actual preparation and engraving of the Greenough Map. Many years afterwards, Greenough published a Geological Map of India—a country which he had never visited—by bringing together all the scattered observations recorded in journals or existing in manuscript in the Archives of the India House. It would not be correct to speak of Greenough’s Map of England and Wales as a mere compilation like his Map of India, for it is evident that in the case of the former map he took much pains in verifying and correcting information upon the ground, as is vouched for by Conybeare and other authorities. On the other hand, Greenough’s claim that his map should be regarded as an independent work, when compared with that of William Smith, is one that no geologist who has studied the question can reasonably allow. In saying this we do not for one moment impugn the good faith or question the honesty of Greenough. Owing to the unfortunate procrastination | of William Smith in the matter of publication, many of his ideas and discoveries had become public property, even before the com- mencement of the century, and Greenough may very well have been quite unaware how much of the current information on the succession and distribution of the English strata was directly traceable to the labours of Smith. In 1865, when the Greenough Map had become the property of the Geological Society, and a third and revised edition was being prepared, a Committee of the Society, which included Godwin-Austen, Murchison, Prestwich, and Phillips, deliberately recommended, as the result of their inquiries, that the map should henceforth bear the imprint “ based on the original map of William Smith”; and every unprejudiced student of the history of geology will agree that the action of the Council in adopting this suggestion was a wise and just one. Apart from his industry and perseverance in Cartography, it must be admitted that the claims of Greenough to be regarded as a pioneer in geological research cannot for one moment be compared with those of William Smith. In the same year that his map appeared, Greenough published his work “A Critical Examination of the First Principles of Geology ” ; and an inspection of this work will satisfy any geologist that even _ at that date he held the most uncertain views concerning the use and ~ value of fossils, and, indeed, upon all geological principles that were not included in the creed of the straitest sect of the Wernerians. In 1812 Greenough laid the first draft of his map before the Council of the Geological Society, and in the same year William ~ Smith at last found a publisher for his great work in the enterprising John Cary. Prof. Judd—The Earliest Engraved Geological Maps. 101 While constructing the small manuscript geological map of England and Wales, William Smith became convinced, as he tells us, that ‘the intricacies in the marginal edges” (of the strata) “ were such that I found to mark point by point, as the facts were ascertained, was the only way in which I could proceed safely. My experience in what I had done upon the Somersetshire Map was sufficient to convince me of this, and that to make a map of the strata on a scale as large as Cary’s England (five miles to an inch) with sufficient accuracy, much of it should first be drawn on a larger scale.” The delay in publishing the work certainly resulted in the Map of England and Wales being much fuller in detail than it would have been if issued in 1801. Instead of the eight colours used in the early map, we find no less than twenty colours employed in the engraved map of 1815; and three other spaces were introduced into the legend, though left uncoloured. We also find separate indications used for collieries, lead-mines, copper-mines, tin-mines, and salt and alum works, while the distribution of the great areas of granite and other igneous rocks were fairly indicated. One very important feature of the map was the inclusion of a section from Snowdon to the south-east of England, in which the superposition and dip of the strata and the formation of escarpments and intervening vales by the agency of denudation are clearly illustrated. The chief defects in the famous map of William Smith, which was at last published on August 1st, 1815, were as follows :—The representation of the Tertiaries was very inadequate, no indication of the Crags being given, the Isle of Wight Tertiaries, the Bagshot Beds of Southern England, and the Boulder-clays of Hast Anglia being all confounded together, and the relations of these to the London Clay being left obscure. The Wealden area was altogether unsatisfactorily treated, the argillaceous strata being coloured as “Oaktree Clay ” and the arenaceous as ironsand (Lower Greensand, etc.). Lastly, the Jurassic estuarine strata of North Yorkshire were confounded with the “carstone and ironstone” of the South-Hast of England. On the other hand, it is interesting to note that Smith had already learned at this early date the existence of strata lying between the Old Red Sandstone and the slaty rocks of Wales and Cumberland. These have a tablet assigned to them in his legend with the description “various alternations of hardstone, limestone, and slate,” though the information he possessed was not sufficient to enable him to extend proper colours for them to the map. This is probably the earliest notice of the strata afterwards made so famous _ by the researches of Murchison and his coadjutors. The period following the issue of his great geological map was one of much activity to William Smith. In the year which witnessed the publication of the map (1815) he issued “ A Geological Table of British Organized Fossils which identify the Courses and Continuity of the Strata”; and in the following year he prepared the first part of his “Strata identified by Organized Fossils,” only four parts of which out of the seven contemplated ever saw the light. In 1817 Smith published an enlarged section from Snowdon to London. 102 Prof. J udd—The Earliest Engraved Geological Maps. This very important work, which was issued by Cary on July 15, 1817, illustrates in a remarkable manner the clearness of Smith’s views regarding both the underground structure of the country and the relations of the forms of the surface produced by denudation to that structure. In May, 1819, there appeared seven other geological sections by William Smith, illustrating the structure of various parts of England, viz.: (1) From London to Brighton through Lewes ; (2) through Dorsetshire and Somersetshire to Taunton; (8) through Hampshire and Wiltshire to Bath; (4) through Norfolk (Yarmouth to Lynn); (5) through Suffolk to Ely; (6) through Essex and Hertfordshire; and (7) between London and Cambridge. In all these sections the relations of the strata with the forms and altitudes of the hills are well illustrated, the only points open to serious criticism being the representation of the relations of the London Clay to the strata above and below it, and the nature and succession of the Wealden beds. In this same year, 1819, William Smith commenced the publication of his ‘“ New Geological Atlas of England and Wales,” a work which, like so many of his undertakings, was unfortunately left unfinished. Two parts of this Atlas appeared in the year named: the first, containing Norfolk, Kent, Wilts, and Sussex, being dated January Ist; and the second, containing Gloucester, Berks, Surrey, and Suffolk, bearing the date of September Ist. In fulness of detail these county maps are far superior to the corresponding portions of the map of 1815, and they exhibit in not a few cases evidences of great advances in Smith’s knowledge. It was on November 1st of the same year that Greenough’s Geological Map of England and Wales made its appearance. A glance at this map will show that in many respects it exhibits considerable advances in geological cartography as compared with Smith’s map of 1815, or even with the later county maps. But it must be remembered, as already pointed out, that the work was really based on that of Smith, that for the Tertiary formations and the strata below the Chalk Greenough had the invaluable collaboration of Thomas Webster (who engraved the map), and that for all the other parts of the country many of the Fellows of the Geological Society supplied numerous very valuable contributions. On February 1st, 1820, there appeared the third part of Smith’s Atlas, containing the Maps of Oxford, Bucks, Bedford, and Hssex ; and in the same year Cary, who published all Smith’s maps, issued a “New Geological Map of England and Wales, reduced from Smith’s Large Map, for those commencing the Study of Geology.” — This map does not differ in any essential feature from the map of 1815, from which it was reduced. The scale of the map is nearly the same as that of a reduction of the Greenough Map, published in 1826 by J. Gardner; and this latter map has been © frequently though erroneously ascribed to William Smith. In the following year (1821) appeared the fourth part of the Professor Grenville A. J. Cole—On Flame-Reaction. 103 Atlas. It is a very important work, namely, the Geology of the County of York, in four sheets. This is one of the finest of Smith’s works. It is full of admirably worked out details. In the West Riding, the outcrops of the chief of the grit-beds are represented on the map with their relations to the coal-seams, and a fine vertical section of them is given; and in the north-east of the county, Smith clearly defines the estuarine strata of the Lower Oolites as follows: “Sand Rock and Grit Freestone of the Moors, lying over the Alum Shale” (Upper Lias), “ and, in Scarborough Castle Hill, under the Oolite or Calcareous Freestone. A thin coal in the cliffs is worked on the Moors at Danby and other places.” In this work we see the fruits of Smith’s residence at Scarborough, which commenced in the year 1820. The maps of Part V of the Atlas (Leicester, Netaneham Hun- tingdon, and Rutland) were printed in 1821, but the part, according to Phillips, did not make its appearance till 1822. Two years later Part VI, with the Maps of Northumberland, Cumberland, Durham, and Westmoreland, was issued, and this was the end of this very important undertaking, though Phillips informs us that “ other parts to complete this work were left in a state of forwardness.” With the exception of a little “Synopsis of Geological Phenomena,” a single folio sheet printed at Oxford in 1832 at the Meeting of the British Association, the Geological Atlas of England and Wales was the last of William Smith’s published works. It is perhaps not generally known that the plates of Smith’s Atlas seem to have been acquired from Cary by the well-known map-publishers Messrs. Crutchley, and the sixpenny County Maps for many years issued by that firm contain the lines and legends of William Smith’s maps. In attempting to solve various questions that have arisen in connection with the history of these early geological maps of the British Islands, I have received much valuable assistance from Mr. F. W. Rudler, F.G.S., the Curator and Librarian of the Jermyn Street Museum. And to the same gentleman the Department of Science and Art is indebted for the gift of a number of maps which have proved to be of great value in making more complete the series exhibited in the Science Museum. I]l.—On toe Fuame-Reaction oF PotTasstumM IN SILICATES. By Grenvitte A. J. Corz, M.R.I.A., F.G.S., Professor of Geology in the Royal College of Science for Ireland. HEN recently examining a series of igneous rocks for the Geological Survey of the United Kingdom, I required a ready method for the determination of potassium in the felspars, whether they occurred as porphyritic crystals or as microlites in the ground- mass. The ordinary flame-reaction has always been recognized as unsatisfactory in the presence of sodium, and the use of blue glass has been long recommended, of a sufficient thickness to cut off a sodium flame, the potassium flame then coming through alone. 104 ~=Professor Grenville A. i . Cole—On Flame-Reaction. The blue glass usually supplied with blowpipe-cabinets is far too thin, and any strong sodium flame will appear through it as a violet one. On using blue glass 5 mm. thick, all but the strongest light of an intense sodium flame is cut off, and the column or band of flame that does reach the eye appears blue and not violet. On securing, after experiment, a blue glass, or combination of glasses, which gives only this effect, potassium may be safely looked for, and will readily be recognized, even alongside the blue flame due to the presence: of an unusual proportion of sodium. Lithium, it may be observed, is cut off by a much less thickness of blue glass, and can generally, as in lepidolite and spodumene, be recognized by the eye alone, when the assay is held in the very outermost sheath of the Bunsen flame, or barely touching the flame at all. The difficulty, however, in the case of potassium is that the flame is often so feeble that some doubt exists as to its occurrence when viewed through 5mm. of blue glass. Hence intensification has been sought, in the case of silicates, by mixing the assay with powdered gypsum, a method recommended by Bunsen. On thorough heating, even 3 or 4 per cent. of potash reveals itself in this manner ; and Professor Szabo! was confident that he could detect even 1 per cent. The great value of Szabd’s results to geologists is their quantitative character; but his determinations of potassium involve the dipping of the assay into powdered gypsum, instead of its complete ' powdering together with the gypsum. The latter method I have found to be far more certain ; but it is obviously impossible to pick up again on the platinum loop, after powdering, the whole of the assay selected, or a known bulk of it. Hence even the resuits with gypsum have given little satisfaction in practice. It seemed, however, that decomposition of the assay in a bead of sodium carbonate might get rid of the difficulties surrounding the reaction. We should always have the satisfaction of knowing that what we saw could not be due to sodium, for this flame would be eliminated by testing our blue glass in each case on the bead alone. Moreover, the most refractory silicates would be dealt with even more completely than when intimately powdered up with gypsum. Since the simple support used in testing this reaction, and in all such work in the laboratory of the Royal College of Science for Treland, was described in the Geonocican Magazine,” it may seem appropriate to furnish the details of this later process here. The ordinary observations, as arranged by Szabd, may be gone through first, on an assay of the dimensions used by that author. In place of the observation with gypsum, I would venture to — substitute the following. In many cases, such as the determination of the presence of potassium in the groundmass of a lava, it may suffice as the only observation to be made. 1 “Ueber eine neue Methode die Feldspathe zu bestimmen,”’ p. 34 ; Budapest, 1876. * G. Cole, ‘‘A Simple Apparatus for Flame-Reactions’’: Grou. Mac., 1888, p. 314. Professor Grenville A. J. Cole—On Flame-Reaction. 105 (i) From a crushed and pure sample of the silicate or groundmass, select a bulk of about two cubic millimetres. This is about twice the bulk used in the ordinary Szabo reactions. (ii) Place the cone on the star-support round the lower part of the Bunsen-burner, the flame rising some 15 cm. above it. (iii) On the end of the platinum wire make a loop about 2mm. in outer diameter; dip it into water—all ordinary waters are sufficiently free from potassium—and pick up on it powdered sodium carbonate. Fuse this into a bead covering the loop. (iv) Examine the flame produced by this bead through 5 mm. of blue glass, and note that the blue column in the flame has no violet: fringe. : (v) Remove the bead from the flame, dip it into water, and pick up the selected particle or particles of the assay. (vi) Fix the wire on the support, so that its loop falls in Szab0’s position, in the edge of and enveloped by the flame, and 5mm. above the top of the cone. Leave it for two minutes, noted by the waich. (vii) Then examine the resulting flame edgewise, i.e. with the plane of the blue glass upright and parallel to the length of the wire. If potassium is present, a violet flame will be seen, on the inner side of the blue column produced by the intense sodium. The intensity of colouration is as important quantitatively as the extent of the flame. This flame is persistent for ten minutes or more, and may thus be examined at leisure. (viii) In some few cases, a further intensification may be required. - Remove the bead, dip it into a drop of strong hydrochloric acid, and insert again in the flame. The flames from the chlorides thus formed rival those produced by the sulphates under the best con- ditions of the experiment with gypsum. I find it sufficient to tabulate the results obtained by the method described in paragraph vii under three grades:— Grade 1 = about 4 per cent. of potash. » AS mo fe ” ” ” 3= ” 12 ” ” I would advise each worker, however, to establish these grades for his own eye and his own blue glass, upon specimens of known and analyzed minerals. Where only the qualitative result is required, the flame may be viewed from the back, ie. along the platinum wire, when a violet flame of varied intensity will easily be detected, occupying almost all the region covered by the flame rising from the bead. As examples of the use of the scale above suggested, the following results may be quoted. The burner used was 9mm. in inner diameter; the cone was 5cm. high, and its top was 8) mm. above that of the burner; the flame was 18cm. high, and 145 mm. above the top of the cone. Grade less than 1.—Oligoclase, Ytterby. Flame just perceptible in some experiments. Average of six published analyses gives K,0O = ‘62 per cent. 106 Professor Grenville A. J. Cole—On Flame- Reaction. Albite, Amelia Court House, Virginia. No result. K,O=°-43. Albite, Zoptau, Moravia. No result. Grade 1.—Apophyllite, Squire’s Hill, near Belfast. K,O probably = 4or 5d percent. Analyses of other apophyllites give 3:10—6-30.. Biotite, Miask. This is a low result, but one analysis gives K,O as low as 5-61, while the potash in biotite from other localities may — sink to less than 1 per cent. Grade between 1 and 2 (1:5).—Hleolite, Brevig. K,O = 5-17. Eleolite, Magnet Cove, Arkansas. K,O = 5-91. Anorthoclase, Pantelleria. K,O varies from 2:53 to 5-45. Obsidian, Lipari. K,O= 5:1. Pitchstone, Corriegills. K,O = 4:7. Groundmass of Phonolite of the Schlossberg, Teplitz. The bulk- analysis of the rock has K, O = 6°57. Groundmass of Phonolite of the Schlossberg, Briix. This is full of small nepheline crystals. Grade 2.—Muscovite (probably Russian). K,O probably = 9 or 10 per cent. Biotite, Burgess, Canada. Intensified to 25 by HCL K,O probably about 8 per cent. Grade between 2 and 3 (2:°5).—Porphyritic Orthoclase (Sanidine) in trachyte of the Drachenfels, near Bonn. Average of five analyses gives K,O = 9-7. Groundmass of Phonolite, Schloss Olbriick, Eifel. Rich in minute leucite crystals. Compare with the figures above given for . phonolites rich in nepheline or nosean. Grade 3.—Microcline, Pike’s Peak. Orthoclase from drusy cavity in granite, Slieve Donard, Mourne Mountains. Orthoclase (Adularia), Schwarzenstein, Zillerthal. Leucite. K,O = about 20 per cent. Evidently all true orthoclases, with their K, O = about 13 per cent. (theoretical 17 per cent.), come in grade 38. Soda-orthoclase will give 2°5, and anorthoclase 1:5 or even lower. Spodumene, with its good lithium flame visible to the naked eye, gives no result through the blue glass used in these experiments. Lastly, the advantages claimed for the employment of sodium carbonate in place of gypsum are:—(1) The certainty in each case that the sodium flame is clearly differentiated from that of potassium ; we have a large quantity of sodium present, and we have eliminated its effects. (2) Complete decomposition of the assay. (8) Security — against loss of the assay when picked up on the moistened bead and inserted in the flame. It is quickly fused in and absorbed. (4) Since the operation is always performed in the presence of — sodium, there is no need for elaborate cleaning of the wire after each experiment, or for the use of distilled water. Prof. H. G. Seeley—On Oudenodon from the Cape. 107 III.—On Ovprvopow (AvtLacocePHaLUs) PITHECOPS FROM THE Dicynovow Brps oF Hast Lonpon, Carre Conony. By H. G. Szetey, F.R.S., Professor of Geology, King’s College, London. "ae genus Oudenodon of A. G. Bain, 1856, was adopted by Sir Richard Owen, and defined as comprising Anomodont reptiles of the type of Dicynodon, but absolutely toothless. Still, they were referred to a family Cryptodontia, under the belief that the teeth were immature and had their development arrested, so that they never descended to the adveolar margin. A transition might easily be made from the caniniform production upward of the alveolar border seen in Oudenodon to the small teeth in Dicynodon dubius and D. recurvidens, which are in contrast to the great lateral ridges formed by the roots of the teeth in most species of the genus. The species séirigiceps was referred first to Dicynodon and then to Oudenodon. Owen described eight species, which differ from each other in the elongation of the head, in the form of the preorbital region and its prolongation in front of the nares, in the forms of the orbits of the eyes, and the anterior nares, and in the median postorbital region being either a sharp ridge or a more or less flattened concave channel. These characters might have been used to define genera. The species fall, more or less easily, into two groups, and this is also true for Dicynodon. The same characters differentiate the ‘short-nosed from the long-nosed species of both types, suggesting that the genera based on presence or absence of teeth in this case are artificial. Thus, the short-nosed Oudenodons are almost in- distinguishable except as species from the short-nosed Dicynodons ; and the long-nosed Oudenodons similarly approximate in skull-shape to the long-nosed forms of Dicynodon. I therefore propose to divide Oudenodon into two subgenera. The short-nosed types, with a wide flattened concave region between the temporal vacuities, the parietal foramen in its middle length, and orbits more or less circular and directed forward and upward, are represented by the species O. Baini, O. raniceps, and O. megalops. They may be indicated by the name AULACOCEPHALUS. The prognathous species have the orbits more lateral, the parietal foramen just behind the orbits, and a sharp median ridge between the temporal vacuities which may extend along their length or be limited to a part of it. This group is represented by the species O. magnus, O. prognathus, O. brevirostris, and O. Greyi, and may be indicated by the name RHacHIOCEPHALUS. In the same way I would divide Dicynodon into two subgenera. The short-nosed species have a broad concave parietal interspace between the outwardly inclined faces of the postfrontal bones, which make the inner borders of the temporal vacuities. The parietal foramen is in the middle of this area. The nares are scarcely seen when the skull is viewed from above, and owing to the shortening of the snout the orbits are directed forward. The species include D. Baini, D. tigriceps, and presumably D. testudiceps, and may be defined by the name AULACEPHALODON. 108 Prof. H. G. Seeley—On Oudenodon from the Cape. The prognathous type, with a median crest between the temporal vacuities, includes the species D. lacerticeps, D. leoniceps, D. pardiceps, and D. feliceps. They are grouped under the name RaacHIcEPHA- topon. IThave no doubt that one-half of Oudenodon with the concave parietal region should be closely associated with the similarly characterized half of Dicynodon, and that the half of Oudenodon with a parietal ridge should be associated with the Dicynodonis which have the same character. Yet owing to the absence and presence of teeth in the two groups there may be some convenience in keeping the types distinct. In tabular form these species may stand thus :— OUDENODON. Aulacocephalus. Rhachiocephalus. Baini. magnus. raniceps. prognathus. megalops. brevirostris. ? strigiceps. Greyi. Dicynopon. Aulacephalodon. Rhachicephalodon. Baini. lacerticeps. tigriceps. leoniceps. testudiceps. pardiceps. feliceps. Almost all these specimens were obtained from the Graaff Reinet district and the Fort Beaufort district, at the time when Cape Colony was expanding to the east, and Mr. A. G. Bain was engaged in making military roads. The Aulacephalodon tigriceps is from the Gonzia River, Kaffraria; and Aulacocephalus raniceps from Hast London. As the strike of the beds is the same from Graaff Reinet to Hast London, ESE., it is probable that these fossils occur upon a definite geological horizon, above the zone of Pareiasaurus and Tapinocephalus, and below the zone of Ptychognathus (Lystrosaurus), near the bottom of the Middle Karroo, in what have been termed the Beaufort Beds. Many years ago Mr. McKay, of Hast London, sent to this country _asmall collection of fossils from the black slaty rocks of the Hast London district. Professor Huxley in 1868 selected one of these as the type of the genus Pristerodon, described in the GroLogicaL Macazine for that year, Vol. V, p. 201, Pl. XII. The collection also included a small Oudenodon now catalogued in the British Museum (Natural History) under the number R. 1819, which is distinct from all described species and may be referred to as Aulacocephalus pithecops. It is somewhat crushed, and is remarkable for its small size, being only three inches long. It is distinguished by the very large size of its nearly circular orbits, which are placed in the middle length of the head, have a diameter of => inch, and approximate closely to each other, so that the frontal — interspace between them is narrower than the concave parietal area, which is its hinder prolongation. The species is defined from O. magnus by the concave parietal region; from that species and Prof. H. G. Seeley—On Oudenodon from the Cape. 109 O. prognathus by wanting the anterior angle to the eye. It is separated from 0. Greyi by the same characters, as well as by wanting the large anterior nares of that species, and by having the tamporal vacuities elongated from front to back. It has a relatively longer nose than O. megalops, has not the eyes so far forward as in O. Baini or O. brevirostris ; and the skull is much narrower than in the Hast London species O. raniceps and differs in its proportions, being of thin and delicate build, while O. raniceps has the bones relatively strong. Oudenodon (Aulacocephalus) pithecops, Seeley, sp. nov. From the Dicynodont Beds of East London, Cape Colony. Restored from [R. 1819]. Preserved in the Brit. Mus. Nat. Hist. 4% less than natural size. The skull is depressed, about twice as wide as high, and measured transversely in front of the orbits, it is half as wide as long. The preorbital region forms nearly an equilateral triangle, conical, rounded from above downward and from side to side. Towards the extremity of the snout, on each side there is a longitudinal depression, extending from the orbits forward to the nares. Those openings were small, and at present are obscured with matrix. The orbits almost suggest the eyes of a lemur in their large circular form; their chief direction is upward and outward. The interspace which divides them is about one-third the diameter of an orbit. The maxillary border extends back as far as the front of the orbit, below which it is notched out and gives place to the malar bar, which contracts a little behind the orbit from above. In side view it is prolonged back parallel to the alveolar margin, uniting in the usual way with the squamosal, and with the vertical bar of the postfrontal bone which descends behind the orbit. The external squamosal element of the zygoma is inclined obliquely outward, and as it extends backward becomes deeper by ascending. Jis upper edge is on a level with the base of the orbit in the malar portion at the back of the orbit, but the concave upper outline of the zygoma is on a level with the middle of the orbit, where the arch terminates posteriorly. It is there inclined inward at an angle 110 G. F. Harris—J ourney through Russia. of 45°, making the outer hinder angle of the head, which is its widest part. The upper surface of the skull suggests a sort of cruciform pattern owing to transverse extension outward of the narrow bars of the postfrontal bones which margin the back of the orbits. The parietal region is concave from side to side, margined in length by sharp — curved ridges which approximate towards each other in advance of the middle length. In that narrowest part of the parietal the ovate parietal foramen is situate. In those curved lateral ridges run the sutures, which separate the flattened oblique posterior plates of the postfrontal bones from the parietals, till near the squamosal, when the postfrontal descends from the parietal ridge upon the squamosal in the usual way. These oblong postfrontal plates make right angles with the margins of the parietal bones to which they are external ; they face towards the zygoma, and posteriorly the postfrontal and zygomatic areas unite in a concavity which emarginates the squamosal bone, and forms the upper lateral outline of the back of the head, on each side of the narrower and shallower concave parietal area between. The temporal vacuities are fully half as long again as wide, and well exposed laterally owing to the low level of the zygoma. The brain-case appears to be closed by the usual bones which form | the vertical occipital plate. They are slightly displaced. The supra-occipital bone is quadrate and single. ‘The interparietal is above it. There is no evidence that the exoccipital bones form the occipital condyle in the way affirmed for Oudenodon raniceps, but the exoccipital bones are large. There is no descending quadrate pedicle, but the quadrate bone is short; and the articulation for the mandible appears to be above the level of the occipital condyle, though that structure is not clearly shown. Seen from the side the superior contour of the head is gently arched from front to back. It will thus be evident that this species is distinct, and in some details of the articulation for the lower jaw shows characters which are exceptional in the group to which it belongs, though all the short-nosed species have the skull depressed behind and wide from side to side. IV.—NaRRATIVE OF A GEOLOGICAL JOURNEY THROUGH Russia. 2. Finuanp (continued from p. 15). By Gzo. F. Harris, F.G.S., M.S.G.F., ete. ROCEEDING in a westerly direction from Tammerfors, we stopped near the station of Siuro to examine some railway cuttings where good sections of gneissose rock and mica-schist, both of Pre-Bothnian age, occur. Macroscopically, the gneissose rock is distinctly and regularly foliated, having small, lenticular, - streaks of quartz abundantly disseminated. Locally, however, the section in the field exhibits much contortion; and thin, irregular, veins of quartz, manifestly of secondary origin, are not uncommon. G. F. Harris—Journey through Russia. TL Under the microscope this gneissose rock presents evidence of great strain and mechanical movement. The quartz, the most abundant mineral present, has been crushed to such an extent as to assume a cataclastic structure, and nearly all the fragments show character- istic mechanical deformation. In addition, the fragments have been arranged in closely packed layers, and where the shearing proved too great for them they have been broken through along these layers; in the undulating cracks thus formed mica occurs in some abundance. It is this structure which renders the rock so distinctly foliate. Felspars are not common in my hand-specimens, and those present are also much broken up. In one micro-slide, however, I find a rather large fragment of a triclinic felspar, much altered _ by crushing; it is too far gone to enable it to be satisfactorily determined, but presents the general features of microcline. This comparatively large fragment forms the nucleus of a lenticular, augen-like structure, bounded for the most part by mica, interrupted here and there by minutely crushed quartz which invaded the nuclear area. Many of the quartz fragments in the rock exhibit secondary enlargement. This gneissose rock at Siuro occurs near the junction of mica- schist with an immense massif of porphyritic granite. The next section we examined was in the railway cutting, a little to the west of the station of Suoniemi, where the Pre-Bothnian mica-schist is well exposed. This rock presented no points of special interest. It is reddish-brown in colour, fine-grained, and well foliated. In thin sections, under the microscope, it is found to consist of deformed angular fragments of quartz interspersed amongst orientated minute films of sericite. Large masses of muscovite occur in blocks by the side of the railway, but I did not see them in siti. Fie. 3.—Section in a ‘‘leptite’’ quarry, Mauri, Finland. A railway cutting near Kulovesi showed an indescribable mixture of schist and small veins of granitic rock, on the top of which were a few feet of glacial clay said to be of marine origin, but we saw no fossils. It was an impalpable mud of brownish-green colour. Walking northwards from this place for a couple of miles, we came to the hamlet of Mauri, and penetrating a wood found a most interesting exposure (Fig. 3) of a rock called by Mr. Sederholm 112 G. F. Harris—Journey through Russia. “leptite.” It may be described as a foliated arkose, containing, however, much minute quartz. The rock is salmon-pink in tint A conglomerate of the same material runs through the quarry This has been severely dealt with; the metamorphic action which rendered the sandstone foliated has drawn out the original pebbles into long lens-shaped patches, the major diameters of which, in all cases, are parallel to the folia. Macroscopically there does ‘not — appear to be much mica; but micro-examination proves that that mineral is fairly abundant in exceedingly minute flakes. To the naked eye all the mica appears white, or bronze-coloured, though thin sections of the rock demonstrate the existence of a little biotite. Evidently the colourless mica has been produced at the expense of alkali-felspars, and the felspathic constituents as seen in the rock, as it stands at present, have largely become saussuritic. The larger fragments of quartz are very interesting. If I dared use the term in reference to a foliated rock I should say that they act as phenocrysts, for that is exactly what they resemble when one first glances at them under the microscope. They are scattered amongst the exceedingly minute fragments of quartz, altered felspar, and mica, which form a kind of groundmass, out of which they stand conspicuously ; and they have been broken up into small fragments by the crushing and shearing to which the rock | has been subjected, whilst they present the usual phenomena of cataclastic structure. The evidence in the field is clearly borne out by micro- examination. J wish we had had more time at this spot, for I feel convinced that much light on an interesting phase of dynamo- metamorphism would be shed by a careful examination of the district. This leptite is foliated enough to place it beyond the pale of an ordinary arkose, and yet not sufficiently to cause it to be regarded as a true schist. In respect to the relative age of this rock—unfortunately, its junction with the schists near Kulovesi railway station is a fault, and along that line of junction was the only hope of determining its position with reference to the older rocks of the district. At the same time, it is believed that it is younger than the granites of the area, as these latter are brought up against, but-do not cut through it. Following the classification detailed in the last article, this leptite and conglomerate are distinctly Pre-Cambrian. But they are, no doubt, much younger than the Pre-Bothnian gneiss. The next day was devoted to an examination of some rocks on the shores of Lake Nasi (Niasijarvi). We set out in two enormous barges which had been decked over for the occasion, and these were drawn by two very fussy little steam-tugs. It is almost needless to say that nearly all Tammerfors came out to see us off. After a boisterous passage to the other side of the lake, our first point d’appui was the locality where “archean ~ fossils” are found. The landing, and then slipping over many hundred yards of well-polished rock with beautiful glacial striae, proved rather exciting, which excitement was considerably G. F. Harris—Journey through Russia. 113 accentuated as two or three members fell into pools of water conveniently arranged by Nature in big and deep holes in the immediate vicinity of the ‘ Pre-Cambrian organic remains.’ The “archzan fossils” gave rise to an animated discussion. There, on the smooth surface of the phyllades, we saw some circular and ovoid markings outlined by black carbonaceous- looking rings. Nobody seemed to know what they were, and it is to be observed that no one even ventured to give them a generic and specific name “ in order that they may hereafter be identified.” Vague remarks about ‘fossil wood” ime. ‘impure phyllades ” closed the visit to this spot. Re-embarking, we went to an re in the lake, where a remarkable phenomenon awaited investigation. I have said (p. 15, ante) that the Bothnian schists in the neighbourhood of Tammerfors are characterized by the presence of conglomerates on several horizons. As we landed on this island the large pebbles in one of these conglomerates, many of them 3 and 4 inches in diameter, were very conspicuous, and the bed here cropping out must be many yards in thickness. Although indurated, and to a certain extent otherwise metamorphosed, this conglomerate is fresh enough to enable each pebble to be clearly made out, or defined from amongst its neighbours. On the beach the rock is much weathered, and decomposition has set in on the surface of the majority of the pebbles, which are pitted with small holes. Beautiful little faults, having a throw of a foot or so, are seen in several places ; they go right through the pebbles, and slickensides is not an uncommon phenomenon. The structure of this archean conglomerate exhibits a few points of interest. In addition to the larger stones mentioned there is much grit and fine quartzose sand, the grains of the latter being angulate. The larger pebbles are for the most part fragments of volcanic rocks presenting large phenocrysts of a triclinic felspar. It is difficult to determine the precise nature of these volcanic rocks, but in one of my micro-preparations there is certainly a small pebble of « labrador porphyry.” The extinction angles of four large phenocrysts of the felspar in this are + 34, ie. + 36, +35, indicating labradorite. These phenocrysts, however, are much altered and have many inclusions. The augite is not very satisfactory and cannot be distinctly identified ; ‘T infer its former existence by green decomposition products in small phenocrysts having the approximate appearance of augite. In ‘addition to these pebbles of volcanic rocks the conglomerate is made up of pieces of rolled phyllade. Mr. Sederholm remarks ' that all the rocks represented by these pebbles crop out to the south of the conglomerate, and there is, therefore, no reason to suppose they have travelled very far. But he mentions some strangers to the district as occurring therein, viz., ‘“‘ deux variétés de granite ou syénite quartzifére, et une diorite quartzifére.” 1 Guide xiii, ‘*‘ Les Excursions en Finlande,’’ p. 4. ? ’ DECADE IV.—VOL. V¥.—NO. III. 8 114 G. F. Harris—Journey through Russia. - Perhaps the principal point of interest in this Archean con- glomerate is the change which some of the smaller fragments have undergone. These adhere to each other for the most part, but here and there is some well-developed granular quartz which acts as a partial cement. The smaller clastic material consists of pieces of plagioclase, fragments of uralitic augite, of quartz, and perhaps of olivine. There has been a great deal of alteration and secondary development in these fragments and the cement. That might have been surmised from the condition of the augite, as just mentioned, almost completely altered into uralite; whilst the olivine is partially changed to biotite and similar products. Running through this finer clastic material and the cement are roughly parallel lineations of uralite, which is also seen bordering some of the larger pebbles. It is accompanied by occasional minute flakes of biotite. The rough attempt to produce foliation in this conglomerate and much of the change induced in the pyroxene was doubtless brought about by the same processes which converted the neighbouring volcanic tuffs into uralite schists—for the conglomerates alternate — with “beds” of these schists. Leaving this interesting little island we went across the bay of Hormistonlahti, and landed to make a further examination of the conglomerates and to inspect the uralite schists. The whole - of the rock is vertically disposed. These dark-green schists have not been very much altered; their foliation is not conspicuously marked, though distinct enough when closely examined. The volcanic ejectamenta are small, but the fragments, as seen under the microscope, are sufficiently large to enable their basic character to be distinctly made out, and they do not seem to have suffered much in the conversion of the tuff into a metamorphic rock. As will be readily understood, the uralite is for the most part orientated and is the principal assistant in producing the foliate structure. This mineral is most completely formed, and actinolitic needles are not only spread all over it, but project from its sides in characteristic fashion. The needles also have a direction parallel with the folia and impart a semi-fibrous aspect to the mineral. A brisk walk along the beach enabled us to see that the uralite schist was remarkably uniform in character for long distances ; I did not observe any contortion in it. There appeared to be but few exposures inland, a mantle of glacial beds spreading over the surface of the ground and masking the solid beds beneath. But you cannot see far in this part of Finland after you have left the lake-side. The glacial beds give rise to a luxuriant vegetation, and though the trees are not very tall they are sufficiently numerous and close enough together to prevent one from observing much more than arises along the immediate vicinity of the route traversed. Regaining the barges, we made an earnest attempt to negociate the lake; the little steamers did their best, and in a short time we had covered 12 or 14 miles, in a northerly direction. Landing again some few miles south of Teisko, opposite a grand section in the glacial beds, full of boulders and small fragments of rock, G. F. Harris—Journey through Russia. 115 we climbed a hill to examine an outcrop of granite. We also got out to look at some diorite which has broken its way through the granite. The outcrop of the diorite is very small, not more than a few yards across; but the granite extends for hundreds of miles over this part of Finland. It is the typical Post-Bothnian granite alluded to ante, pp. 14,15. Thin sections show the diorite to be a rather formidable compound ; for it is a quartz-mica-hornblende diorite, the whole being much decomposed. ‘There is a considerable quantity of opaque iron disseminated throughout, and my slide shows both black and white micas, though the latter is very rare. In a little time we arrived at the house of the hospitable proprietress of Teiskola, the most northerly point of our journey ; and later on the little tugs took us back down the lake some 20 miles to Tammerfors, sending myriads of sparks from the wood fires flying out of the funnels on the way, the display resembling ‘ fireworks” in the cold night air. Up early the next morning, we trained to the station of Suinula, a mile and a half from which place we visited an exposure of gneiss. Farther on, along the railway line, near Orihvesi, we came to some large railway cuttings exhibiting the contact between the Tammerfors schists and the porphyroid granite. There seemed to be much difference of opinion as to the precise nature of this junction, which latter, however, was most clearly shown. Our Director, Mr. Sederholm, said that the junction was “ mechanical.” In the same section is a whiter granite, younger than the schists, which often contains tourmaline. The porphyritic granite contains many fragments of schist which have been to some extent absorbed by it. The micro-structure of such a fragment shows it to be a typical biotite schist, but having a little white mica; the quartz is in small angular grains and exhibits the usual cataclastic phenomena. Many of the larger quartz crystals have been crushed in siti, the original boundaries of each of these little groups being clearly definable. Retracing our steps from Orihvesi to Halimaa, we went for a long drive to Kangasala, where we made our first personal acquaintance with asar. This gives me an opportunity for saying a few words concerning the superficial deposits of Finland. The greater part of the solid rocks of the country are covered by morainic deposits. These are specially well developed, and form one continuous sheet in the north, central, and eastern portions of the land. In the south-central parts this sheet is much interrupted by innumerable lakes, along the shores of which some of the best sections are exposed. The country along the eastern boundary of Finland from near the north of Sweden to the shores of Lake Ladoga is all mapped as ‘“ morainic deposits.” They are a monotonous series of mixed gravels and sands. On the other hand, in that portion of the country bordering the Gulf of Bothnia and the Gulf of Finland, Glacial and Post- Glacial clays are well developed, and crop out in every little river valley for many miles inland. The greatest expanse of this clay is to the south of Uleaborg, and in the immense tract of 116 P. M. Kermode—Cervus giganteus in the Isle of Man. country to the north of Abo and Helsingfors. Near Uleaborg, also, are extensive deposits of Post-Pliocene sand, smaller patches of which are met with at intervals in the western parts of the country and bordering the Gulf of Bothnia. In the interior of Finland this sand also occurs, and large outcrops are mapped to the north-east of Teisko and near Lake Ladoga, and on towards St. Petersburg ; in the southern part of Finland, however, it is but sparingly represented, and it does not appear to occur at all in the northern part of the country above Uleaborg. Perhaps, the most interesting glacial deposits of Finland are the asar and stratified terminal moraines, which in some instances stretch uninterruptedly for many miles across the country. We had abundant opportunity of examining these at typical localities, as will presently be described. Confining attention to the neighbourhood of Tammerfors for the moment, I may remark that the geologists of Finland are of accord that glacial phenomena there are not so simple as in other parts of the Grand Duchy. Messrs. Sederholm and Ramsay state! that there are several systems of glacial strie. The predominating directions are “S. 25°-30° H. et 8. 60°-65° H. (cété frappé au N.-W.).” To the south of Tammerfors the striations run W.—-E., and sometimes N. 65° EH. These diverse directions are explained as. being formed during the retreat of the ice; but to the north of the town there are strize running S. 5° E., and belonging without doubt to a more recent system, which is connected with a large terminal moraine found to the north-west of Tammerfors and which, by its configuration and sandy composition, resembles an as. What is believed to be the oldest system of glacial strize in the district is in the country to the south of the town where the grooves run N.and§. The morainic gravel throughout is remarkably uniform. The glacial clays in the southern part of Lake Nasi are recognized as marine “ Yoldiu-clays,” and there is also a fresh-water deposit. (Zo be continued.) V.—Tue “TIriso Hix,” Cervus GigANTEvs, In THE Isue or Man. By P. M. C. Kermops, Esq., Hon. Sec. Isle of Man Natural History and Antiquarian Society. N September last the Committee appointed by the British Association to ‘examine the conditions under which remains of the Irish Elk were found in the Isle of Man” commenced excavating at Close-y-garey, near Poortown; but owing to the unusual amount of water, considerable labour and expense were incurred in the preliminary work of draining, and by the 25th September the grant was exhausted. Our local Committee thereupon took up the work, issuing a circular for subscriptions, the response to which enabled them to carry on the excavations with such success that on the 30th 1 Guide (op. cit.), p. 8. P. M. Kermode—Cervus giganteus in the Isle of Man. 117 September portions of what appeared to be a perfect specimen were disclosed in the undisturbed marl. ~The dub, or old marl-pit, in question, lies in a hollow in the glacial drifts, about half a mile south of the Peel Road Railway Station, on the east side of and close to the line. It had about sixty years ago been worked for marl, and the present well-defined banks mark out a rectangular hollow about three feet below the surrounding surface, measuring about fifty yards square. Across one corner of this a trench was dug to carry off the water, and the operations of the Committee were confined to a triangular area on the west side of the*trench, measuring about 15 yards east and west by 380 yards north and south. We excavated all over this space to a depth of nine feet and more. The first four excavations being through ground which had previously been disturbed yielded no definite results, but at one point, about 10 yards from the north bank and 8 yards from the west, a few elk-bones were met with in the disturbed soil. These and some other bones were submitted to Professor Boyd- Dawkins for examination, and he finds among them, belonging to this species, . fragments of maxilla, the sixth cervical vertebra, the second lumbar vertebra, and a fragment of a rib. The last excavation, about the centre of our area, brought us to the undisturbed marl at a depth of about three feet. On testing this I found it to extend to a depth of 10 feet 6 inches at a point about eight yards east of the bank, but four yards nearer to the bank it did not reach a greater depth than eight feet. Between this and the bank it appeared to have been disturbed. In this bed of white marl, at a depth of about nine feet from the surface, we found the remains of a complete skeleton, lying on its right side, the head towards the bank, the legs drawn up to the body. We considered it necessary to get it out the same day (Saturday), as already many people had been to the place the previous evening, and some one had broken off a piece of the exposed antler. Had time allowed we should have endeavoured to have cleared away the marl from around the bones and had them entirely disclosed and photographed. Time, however, did not allow of this, and as it was very wet we probably should not have succeeded anyhow. Deemster Gill, Mr. Crellin, the Rev. 8. N. Harrison, and I therefore took very careful note of the position of the bones as they were gradually uncovered and removed. So perfect was the skeleton that we had no difficulty in doing so. The bones were nearly all in juxtaposition and in a fair state of preservation. The left antler had fallen back over the lumbar vertebre; it was rather decayed, the tines had fallen off, and the beam was missing. The other antler had dropped down by the cervical vertebra, and, except for the beam, was in good preserva- tion, but in lifting it from the marl the tines dropped off. Un- fortunately the skull had decayed away and only a portion of the left lower jaw and fragments of the upper jaws remained. The left antler is the larger; it measures across the palm 118 P. WM. Kermode—Cercus giganteus in the Isle of Man. 15 inches, allowing for a piece of the front edge which has decayed away; the right measures 13 inches. With the tines restored, they are respectively 564 inches and 53 inches long, and the beam would have been at least 10 inches more. They show six points or tines, besides the brow-tines, which had fallen off, the part where they joined the beam having decayed away. On laying the bones in position I find that the animal must have been about 18 hands or six feet high at the shoulder. The fact of its having antlers shows it to ihe been a male; and their size and number of tines, that it was an adult. One of the ribs had been broken, no doubt the result of fighting with another buck in the rutting season, and had healed again. The teeth are in excellent preservation, showing no sign of weakness or decay. The limbs are perfect, all the small bones having, I think, been recovered ; the vertebre also are sound and appear to be all present. The right shoulder-blade, which lay beneath the other, is badly decayed, as are many of the ribs, but I think they can be pretty well restored, and, but for the missing skull and the beams of the antlers, the bones when articulated and mounted will make a perfect skeleton. Having secured this specimen, we continued our excavations in an easterly direction, but very quickly got through the marl, and again found the soil to have been disturbed as far as our trench. With regard to the formation in which it was found, the British Association Committee will no doubt have a full report for the meeting at Bristol next September. The result of all the ex- cavations, allowing for the very disturbed state of the ground, shows the following beds :— ft. ins. A. Disturbed soil and peat, an average of about 3 0 B. In one place a blue clay or silt was observed resting on the white marl. C. White marl, containing the elk-remains ... on 6 6 D. Blue marl x © HK. Red sand with gravel 0 3 F. Brownclay .. en ee 0 3 G. Sand and gravel . : 0 3 Hcy \ ? Glacial drift roe As stated above, the whole surface had been lowered about three feet in digging for marl; the peat had for the most part been removed, and a great deal of the marl also; indeed, we were fortunate in finding this one spot in which the marl itself had not been disturbed. The finding of detached bones shows that other individuals of this species had perished here, and is consistent with what we were told, namely, that a specimen had been seen when digging for marl, and that the antlers of yet another had been taken out and sold. We were told also that two skulls without antlers had been seen on the east side of our trench. Samples of the marl and other beds were forwarded to Mr. James ~ Bennie of Edinburgh, for preparation and microscopical examination, and so far as we have heard, the peat appears to be an ordinary lake peat, without anything very distinct about it. The marl contains no G. P. Hughes—The Red-Deer in Northumberland. 119 fresh-water shells, but there seems to be a great number of Ostracoda, also some Chara-seeds. The Arctic crustacean Lepidurus glacialis and the Arctic willow Salix herbacea, which we found in our previous excavations at Ballaugh, seem to be absent from this section. Mr. Clement Reid, of H.M. Geological Survey, has kindly undertaken the determination of the vegetable remains, and we hope therefore to be able to give further information on the subject in our Report to the British Association. In recording this latest discovery of the remains of the great deer, it is of interest to recall the fact that the first specimen to have been set up, if not, indeed, the first almost perfect skeleton found, is that now at Edinburgh, which was found at Ballaugh in the Isle of Man in 1819. Altogether we have been able to trace remains of about twelve individuals, and possibly more may yet be met with, so that a herd of this noble beast must have existed here after the kingdom of Man became an island. It is more easy to account for its disappearance in so small an area than for its original presence ; the best explanation of the latter being that suggested to the writer by Mr. G. W. Lamplugh—that it had crossed over on the ice. It is somewhat remarkable that no other contemporary remains have been met with, unless we may now except Hguus caballus, some bones of which we found at Close-y-garey. From their appearance Professor Boyd-Dawkins thinks these may possibly be of the same age: most unfortunately they were only met with where the soil had been disturbed, but they at least suggest grounds for further search, which I hope we may be able to undertake in the near future. ; VI.—Nores on tHe Rev-Deer, Cervus ELAPHUS, LINN.’ By G. Prinete Huceuss, Esq. M\EHE Red-Deer (Cervus elaphus), or common stag, is a native of the more temperate regions of Europe, Asia, and North America. In Great Britain it has its freedom limited to the Highlands of Scotland, where, however, it is carefully protected, and affords the créme de la créme of British field-sports to the practised rifleman and mountaineer.” In early English History, when the marauding disposition of the people made cattle a precarious property, the wild deer. which depastured the country in large numbers, afforded the staple article of food. Large hunting parties were collected, and as many as 1,000 stags are recorded as having been taken at one of these gatherings.® The true stag and deer are at once distinguished by the presence of deciduous branching antlers in the male, the female being in nearly 1 Read before the British Association, Toronto, in Section D (Zoology), 1897. 2 The shooting of some of the deer forests, of trom 25,000 to 35,000 acres, is let for between £3,000 and £4,000 per annum. 3 The ballad of Chevy Chase records such a wholesale slaughter, though the history of field-sports relieves the statement of any suspicion of poetic license. AU) awe, Jee Jal ughes—The Red-Deer in Northumberland. all cases destitute of such weapons. These appendages vary much in character, being cylindrical or rounded in some species, and flattened and palmate in others. They are bony outgrowths from the frontal bones of the cranium, and, being developed periodically,’ have an important physiological significance. An extraordinary supply of blood seems to be provided for these bony outgrowths at the spring of the year, and the vessels surrounding the frontal eminences enlarge. This increased vascular action results in the secretion of formative bony matter, producing a swelling or budding at the summit of the frontal bones, at the spot where the horns of the previous season had separated. In the early condition the horn is soft and yielding, and it is protected only by a highly vascular periosteum and delicate integument, the cuticular portion of the latter being represented by various fine hairs, closely arranged. From this circumstance the skin is termed “the velvet.” As development goes on, a progressive consolidation is effected; the ossification proceeds from the centre to the circumference, and a medullary cavity is ultimately produced. While this is taking place a corresponding change is observed at the surface. The periosteal veins acquire a great size, and by their presence occasion the formation of grooves on the subjacent bone. At the same time osseous tubercles, of ivory hardness, appear at the base of the stem. These coalesce by degrees, enclosing within their folds the great superficial vascular trunks, which are gradually closed and cease to flow. The supply of nutriment being thus cut off, the first stage of excoriation is accomplished by the consequent shrivelling up and decay of the periosteal and integumentary envelope. The full growth of the antlers is now terminated, and the animals, being aware of their strength, endeavour to complete the desquamation by rubbing them against any tree or other hard substance that may lie in their path. This action is termed burnishing. After the rutting season the antlers are shed, to be again renewed in the ensuing spring; and every year they increase in development, until they attain their maximum growth.” The fossil remains of deer, which have been plentifully found in this country and the North of India, indicate that when unmolested by man and in a wild state they attained a far greater size and probably age than at the present day. The period of gestation of the hinds extends over 8 months, the young being produced in the month of May. During the winter both sexes collect in vast herds; but in the rutting season the stags 1 «Tn the Deer (Cervide) the antlers consist wholly of bone which grows from the frontals, the periosteum and finely-haired integument, called ‘ velvet,’ coextending therewith during the period of growth; at the end of which the formative envelope loses it vascularity, dries, and is stript off, leaving the bone a hard insensible weapon. After some months’ use as such the horns, or more properly ‘antlers,’ having lost all vascular connection with the skull, and standing in relation thereto as dead — appendages, are undermined by the absorbent process and are shed; whereupon the growth of a succeeding pair commences. The shedding of the antlers coincides with that of the hair, and, with the renewal of the same, is aunual.’’—Ouwrn. 2 See Richardson’s ‘‘ Museum of Natural History.”’ G. P. Hughes—The Red-Deer in Northumberland. 121 frequently engage in the most desperate encounters, and sometimes the antlers are inextricably fixed by the tines, both animals being left to perish with interlocked weapons. ‘¢ As when two bulls for their fair female fight, Their dewlaps gored, their sides all smeared in blood.”’ Virnein: A£ineid, xii, 715. Antlers of Red-Deer, Cervus elaphus, Linn: Found by G. P. Hughes, Esq., beneath a peat deposit, Cresswell Bog, eastern base of the Cheviot Hills ; and preserved at Middleton Hall, Northumberland. The specimen of which I submit a photograph is, I have reason to believe, hardly surpassed for size and preservation by any other examples from the peat deposits of Great Britain. The late Karl of Malmesbury, who was for many years tenant of the Auchnacary deer forest in Scotland, and moved among sportsmen of the first rank at home and abroad, saw these antlers, in company with another great sportsman and deerstalker and intimate friend of Sir E. Landseer, the Earl of Tankerville, and was of opinion that only in a few German collections in Hesse Cassel, etc., on the sites of 122. G. P. Hughes—The Red-Deer in Northumberland. the vast forests of Franconia and Thuringia, where giant specimens of Mammalia at one time abounded, would their equal be found. I have, therefore, thought it desirable, as I have no descendant of my own, to have this specimen photographed, and a copy sent to some of our national Museums and Societies, in order to have the existence of this fine pair of antlers of Cervus elaphus recorded in proper form. | MEASUREMENT OF THE ANTLERS PRESERVED AT MippLEeToN Hau, WooLER, NorTHUMBERLAND. - 3 me mM E . Width from inside to inside of the crowns des B00 . Length of the beam to leading crown tine . Width from outside to inside of beam at crown ... . Circumference of the crowns (left)... (right) Rohr + . Saap 5. Length of brow antlers (left) (right) m= oo co & Ob 6. Width of skull at stem : 7. Circumference of stem at base... 000 200 8. Number of points upon the two stems or beams ... FOO O em ON Dore “This set of antlers, with several of less size, with entire skeletons of red-deer measuring 15 hands in height, one foot taller than the red-deer now extant, were exhumed from a lacustrine deposit of | marl and peat known as the Cresswell Bog, at the eastern base of the Cheviot Hills. The following is the section of deposits in descending order as given by Mr. G. Tate, F.G.S., Secretary to Berwickshire Naturalists’ Club :—(1) Peat, in which are prostrate trees of hazel and birch, and also hazel-nuts: from 2 to 4 feet in thickness. (2) Marl, in which have been found skeletons of red-deer, teeth of the boar, and great numbers of fresh-water shells: 8 feet thick. (8) Blue Clay, a few inches in thickness. (4) Boulder-clay and gravel.”—Transactions of Berwickshire Nat. Club, 1860. ° These facts give a tolerably clear history of the succession of events at this spot. During the Boulder-clay period the district was covered with water up to a considerable height. This period, with its subarctic climate, its glaciers and floating icebergs, passed away, and the present conformation of the British Isles was to a great extent assumed. Where this specimen was found a small lake had been left, in which for ages mollusks lived and bred, for the accumulation of 8 feet of marl, chiefly formed of their shells, indicates a con- siderable lapse of time. Deer and boar living along its margin, or coming to it for drink, or, I may add, pursued by wolves or Neolithic man, occasionally found a tomb beneath its waters and yielding marl. In the course of time the waters were partly drained off, but the ground being adapted for the growth of mosses, peat was formed over the marl, and trees and bushes growing around were time after time carried by floods and winds into the marshy ~ ground, which they have contributed to increase and solidify. W. M. Hutchings—Rocks of Great Whin Silt. 123 VII.—Tue Conractr-Rocks or tHe Great Wuin SILL. By W. Maynarp Hurcuines, F.G.S. (Concluded from the February Number, page 82.) N describing “ An Interesting Contact-Rock” (Grou. Mac., March and April, 1895) I gave its analysis, showing :— Potash ... 200 00 abo 500 boo 1-25 per cent. Soda 200 900 600 see 500 eee 2°01 ” And in this rock also the great relative increase in soda corresponds with the appearance of albite among the new minerals. But, as stated above, we also have cases of great alteration without increase of soda; as, for instance, the two intensely affected shales described from Rowntree Beck and Winch’s Bridge, both very rich in alkali, and both showing still a normal excess of potash. And, again, three other specimens of completely altered rocks from near contact give :— Potash ... ... 3°15 percent. ... 4°24 percent. ... 3°40 per cent. Sodamiesemess L320 BS eee lige ie goo | OS7/ 99 Tn these the mica is all regenerated, with chlorite, as described, but there is no sign of any new felspar. Without burdening this paper with too many figures, I may say that in between these extremes of great alteration of alkali-ratio, and no alteration at all, come determinations giving an intermediate result—soda has increased beyond the normal limits, but still not to the extent of exceeding the potash, as for example :— Potash... £3 ane iss 3°55 percent. ... 1°60 per cent. Soda sue abs ae ae 2°20 es soo. alee a If soda-transfer takes place, we should expect to find evidence of it in the less pure sandstones, as well as in the shales, those with argillaceous interstitial matter being really only diluted shales. J have determined the alkalies in three specimens of altered sand- stones, as follows :— 3 per cent. 2, ¢ ah ” Potash om Os Zoe perrcentemen Ooo) pericentsy 2.102 Soda seer) 1 2046 Ss Aero talk As vee, Here there is in each case a very decided excess of soda, and the total alkali contained is much more than would be expected in consideration of the relatively small amount of original argillaceous material. These determinations, as far as they go, would strongly countenance the idea of transfer of soda in some form, and tend also to show that the sandstones have taken it into combination, and held it, out of proportion to the shaly deposit contained in them. Tests of some of the limestones have also been made, for the same reason, that where less pure they contain argillaceous material, and should show the alteration of alkali-proportion if it has taken place. Of the following two analyses, A represents a specimen from within a few inches of contact, containing a quantity of garnet and 124 W. MW. Hi Wecrngnee Rocks of Great Whin Sill. a good deal of recrystallized silica. B is a rock practically free from minerals other than calcite—only a very few garnets and a little quartz :— AN B. SMG, cas én 300 dae 40°90 percent. ... 4°60 per cent. Alumina eat Ms is 5°45 ap Boo os se Ferric Oxide... yee wise 7°88 4 soo ONES) if mee es eases Nh eer a 99.40) 2 SOO eee Magnesia we 660 Bbc 2°17 39 loo 5 otashweres i ee B56 0°28 a BS me OLS) FS Sodaiyeee: ne ae ce 0-74 50 sce MPG 30 Carbonic Acid ... van oe 10-06 ss ooo) wi iY) 3 Water... axe aoe 5n0 2°80 a ton, PNG ae 99°67 100°87 A portion of B was dissolved slowly in dilute cold hydrochloric acid, the residue filtered and dried, and its alkalies separately determined. It gave :— Potash ... are 560 aa has a 0°35 per cent. Soda a : 0-78 ” Another limestone, completely recrystallized, and showing grains and small indeterminable crystals of foreign matter, gave :— Potash ... oe was ae aes isa 0:26 per cent. Soda wee ab Soe sis Gee as 0°81 ” This rock, dissolved in dilute acid, gave a residue which, after filtration and ignition, was 6 per cent. of the original material, and contained :— Potash ... noe See 545 ood bc 0-58 per cent. Soda ae 006 ee : 6°30 ue} All the above show large excess of soda, but amongst the lime- stones, also, we find contradictory results. ‘Thus, one altered bed containing augites, etc., gives :— Potash ... 300 209 a0 200 bo 2°55 per cent. Nodame nee. 200 200 250 350 009 0°62 22 Another hand-specimen shows sugary white limestone, together with a layer of brown hornfelsy rock, due to impurer material. The alkali-contents are :— White Limestone. Brown Layer. Potash ... sed ay 0°30 percent. ... 5°79 per cent. Sodaa ss. BB Ae 0-07 a soa LO sa At my request, Mr. Garwood collected a series of specimens representing the succession of beds downward from the Whin Sill to the basement conglomerate, at Falcon Clints, in Upper Teesdale ; as I thought it would be of considerable interest to make alkali- determinations in them, and at the same time examine them micro- scopically and note the nature and intensity of the alterations. The particulars of the section at this point, as given to me by Mr. Garwood, are as tollows :— W. M. Hutchings—Rocks of Great Whin Sill. 125 WuHin Sitt, 100 FEET THICK. Feet thick. No. 1. Limestone, with garnets, etc., where impure ; white and sugary where pure, but containing patches of altered shaly matter, sandstone, ete. 24 No. 2. Shale, weathered ... axe see ee ea 12 No. 38. Limestone ... See a Woe ae ee 10 No. 4. Shale, weathered tee ae ae 6 No. 5. Limestone ... 0 aa Pon A ae 2 No. 6. Sandy shale : 3 No. 7. Limestone, hard blue, with fossils 8 No. 8. Flaggy sandstone ... : 10 No. 9. Shale with nodules.. ; skis 8 No. 10. Basement conglomerate es B06 2 Total of sedimentary beds 88 The specimens examined gave results as follows :— No. 1.. This limestone has been described above, so far as concerns the garnet and idocrase-bearing hornfelsy alteration-product, of which an analysis was also given. This analysis showed a large excess of soda. But it was another hand-specimen from the same locality, with both pure limestone and a layer of the hornfelsy material, which gave the figures just quoted, showing potash in large excess over soda. In this limestone-bed occur patches and lenticular masses of altered sandstone and shale. A specimen of such a sandstone shows, in the sections, that it is rather coarse-grained, with a good deal of interstitial matter of originally argillaceous nature, with fine- grained quartz. This matter is all intensely altered, showing some newly-formed mosaic of quartz and a little felspar, a lot of white mica in beautiful tufts and bunches, and here and there patches of newly-crystallized, glassy-clear groups of well-twinned plagioclase crystals, some of them identifiable as albite. The alkali-contents of the rock are :— Potash ... ac 206 doe Bo tee 0-55 per cent. Soda ae Bi a: sae ae eis 201 a A patch of shale from the same source shows alteration on the usual lines—much of the indefinite new “speckly ” product, white mica, chlorite, etc., with “spots” containing more chlorite, less mica, and great aggregations of rutile grains. It contains :— Potash ... adie a Bod dos ee 4°82 per cent. Soda ee ae a3 oa Ho tas 1°48 a No. 2. This was a ciency quartzy shale. The quartz is not much affected, but the main mass is greatly altered, chiefly to speckly matter and white mica, the latter often forming clear patches and circular spots of larger, clearer flakes of muscovite, or of muscovite and chlorite. The rock contains :— Potash ... a0 299 as bbe be 5°36 per cent. Sodayuuen: BBC ae oe Ba soc 2°93 ‘es No. 3. Limestone, originally impure with argillaceous matter. The bulk of it is not highly altered, not even rendered coarsely 126 W. MN. Hutchings—Rocks of Great Whin Sill. crystalline. But there are many “spots” in the sections, in which, among a good deal of indeterminable matter, some chlorite, etc., are a good many small bits and prismatic crystals of augite. Some augite occurs also outside these spots, but not much. ‘The alkalies are :— Potash ... 200 500 506 aye ooo 2°55 per cent. Soda) sec. di dae sas us ee 0°62 a No. 4. A main mass of fine-grained shale, in which are bedded good large quartz fragments, with numerous flakes of clastic mica, and a good many grains of calcite. The coarser constituents are not altered, but the finer portion has been completely regenerated, giving rise to a small-grained dim sort of mosaic, with a little new mica, and showing here and there larger patches of this and of chlorite. This rock contains :— Potash ... did 900 Se ae ate 3°55 per cent. Soda tre me ie sts Hest Ss 2°76 is No. 7. This limestone is very much recrystallized, but does not show any distinct new minerals, being only slightly impure :— Potash ... Se 500 300 260 oon 0°26 per cent. Soda ae ae aa S00 ios wa 0-81 a No. 8. A sandstone converted into a quartzite. There was very — little interstitial matter, which is now much altered, but details cannot be made out :— Potash ... es a ah 500 wis 0°23 per cent. Soda wee Ke ae aoe au as ely a No. 9. This is the bed described as “an interesting contact- rock,’ the main characteristics of which were recapitulated above, so that no description need be given here. It was pointed out that the bed varies more or less in composition in different parts, being more or less quartzy, etc. As since IJ first described it I have made some more alkali-determinations on various specimens, it may be worth while to add them here :— per cent. percent. percent. percent. per cent. Potash... 556 WON ono | OPE son | NGO 5 BP oon OO Soda 2: a0 EO cog) PIM) Wee iIE Gag | WS) cog «WBS The last is from a sample representing a large number of the ‘“‘nodules,” which were carefully detached from the rock. We do not know how far from the contact the metamorphism caused by the Whin Sill was capable of extending, but we have here an instance of very great alteration at over 80 feet distance, and may safely say that the action would have continued much further. — From published observations on the subject, it does not seem usual for the contact-zone of basic dykes or sheets to be as extensive as this. The interpretation of the chemical determinations above given does not seem to be an easy or a satisfactory business, owing to their contradictory nature. Many of them show an undoubted access of soda, at least—that conclusion seems to be unavoidable, W. WM. Hutchings—Rocks of Great Whin Sill. 1G unless if can be shown that there are shales, and argillaceous sand- stones and limestones, among the Lower Carboniferous beds, and indeed in the particular districts in question, containing soda in some such ratio to potash as is disclosed by these determinations. On the other hand, it is difficult to explain the fact that such soda- rich alteration-products alternate with others, derived apparently from quite similar original rocks, in which, as we saw, soda has not increased, or has increased in a far less degree. Supposing some compound of soda to pass from the igneous magma into the invaded beds, we can readily explain to ourselves how it could come about that purer limestones show little or no trace of its action. Solutions containing this compound of soda could permeate the limestone, and pass into beds of shale, ete., beyond it, without being in any way permanently taken up and combined with it; and in course of time the limestone would be freed from the merely mechanically held soda; whilst in the complex silicates of the shales would be offered a material with which introduced soda would easily enter into new and permanent combinations. But we cannot very well explain how it is that one bed, or part of a bed, of shale takes up so much more than another. We must leave this, for the present, as one of the many things which we cannot yet make clear. Looking at those rocks which show a considerable amount of soda-felspars, and carefully observing the part these felspars play in the structure of the rock, and their relationships to the other minerals, it does not seem possible to conclude otherwise than that the soda-increase and formation of these felspars and these structures were all part of the one process of contact-metamorphism and recrystallization of the rock-constituents. No later introduction of soda, by percolation of solutions from the cooled and weathering igneous rock, is at all consonant with what we see. And this is equally true of those beds in which, though we find soda in excess, we cannot detect any felspar with the microscope, and are led to assume that the soda is combined in the abundant new mica developed, in the “speckly ” intermediate material, and in other new products. In this rather indefinite and unsatisfactory position we must, apparently, leave this part of the subject for the present, at all events so far as the Whin Sill is concerned. Having devoted a good deal of time and trouble, both to “looking it up” elsewhere, and to trying to obtain evidence from our most favourable British opportunity of studying it, 1 make no apology for dealing with it at some length, even though, unfortunately, not conclusively. It touches one of the most important points which still stand first for consideration on our way to an understanding of the true nature and processes of contact-metamorphism. Incidentally, it is worth pointing out that the series of alkali- determinations given above, supplementing as they do my previous analyses of fireclays and shales, quite definitely dispose of the contention, often put forward, that none of these deposits contain 128 W. MM. Hutchings—Rocks of Great Whin Silt. enough alkali to justify the belief that they could be the early material of true clay-slates, ete. It is not, however, in this chemical question, nor yet in the mere cataloguing and description of the new minerals produced, that the great interest of the contact-rocks of the Whin Sill is centred. This interest mainly lies in the observation of the nature of the structures produced, and the relationships of the minerals to one another; and in the comparison of these structures with those of rocks from great contact-areas round granite intrusions, as well as with those of others, of similar composition, which have been subjected to intense dynamic and deep-thermal conditions, but not, so far as we know, to the action of any intrusions of igneous masses. When a shale is highly altered by contact with the Whin Sill, we get in most cases, as has been shown, a splitting-up of the complex micaceous mineral of which it largely consists, into a purer, more highly developed white mica, which we may in general designate as muscovite (though to some extent it may consist of paragonite or of an intermediate stage), and into a chloritic mineral. Both the mica and the chlorite crystallize in the rock in all directions, quite irrespective of the stratification-plane in which the original micaceous minerals lie flat. A certain criss-cross structure is at once produced ; it commences as soon as the contact-effect is noticeable at all, becomes more and more pronounced in the more highly developed cases, and is often accentuated by the formation of rosettes and sheaves of mica and chlorite. These effects and appearances are all the more striking because they are produced on an original material of such low development. We pass at one step from a rock with no white mica, no chlorite, and no criss-cross structure, to one in which all these things are in full evidence. At granite-contacts we may often see exactly the same products in the altered rocks, but they are then frequently, in that sense, not so striking; because in most cases the rocks acted upon have been in a much higher stage of development; they were not elementary shales, but slates, in which a good deal of formation of mica and chlorite had already taken place. The final result is, however, the same in both cases, and is also the same whether the granite acts on a mere shale or on a slate; we get a pure white mica, and a corresponding separation of chlorite or its equivalent in biotite, cordierite, etc., all crystallized in every direction in the rock. To make out the minerals and the structures in the Whin Sill rocks we may need high powers, whereas we may see all these things with low powers, or a pocket-lens, in the sections from a granite-contact; but this is a matter of no importance, and is — related to nothing beyond the respective bulks of igneous rock concerned, and probably also the greater or lesser depths of the invaded rocks, with corresponding differences of their initial tem- peratures. The same considerations apply also to the frequent abundance of certain special minerals at granite-contacts, and their absence, or rarity, in the Whin Sill rocks. Leaving aside these conditions of mere size and intensity, the results are strikingly W. M. Hutchings—Rocks of Great Whin Sill. 129 parallel ; and a concurrent examination of a series of rocks from the two sources does not fail to impress one with the idea of how relatively slight and mild a degree of contact-action is required 1o bring about certain very definite and characteristic effects. I have compared these Whin Sill rocks over and over again with contact- rocks from several localities, and quite recently, whilst once more passing them in review in connection with the putting together of these notes, I have had the opportunity of looking at them side by side with a fine series from Scotland. One can often pick out examples of both, which, barring certain minerals (as e.g. kyanite), are so exactly similar in structure and general nature, that the slide from the granite-contact might be almost imagined to be derived from one from the Whin-contact by some process akin to photo- graphic “enlargement,” every detail being reproduced. But, on the other hand, we may compare these Whin Sill sections with any number of examples of rocks which have suffered the most intense degrees of crushing and shearing, and which have been under enormous depths of cover, without being able to find in these latter any signs of even a commencement of the characteristic structures, or more than a very moderate amount of the mineralogical development. Such rocks as these, as I have shown in former notes (e.g. Guont. Mac., July and August, 1896), certainly display a decided degree of advance beyond the clays and shales from which they started. We have the formation of new mica and of chlorite, going along the same chemical and mineralogical lines as in contact- action; but it does not seem to be able to pass beyond relatively moderate limits, giving us a still impure mica. And in the matter of structure the limits are still more restricted. We do not get beyond a felted and wavy mass of mixed mica and chlorite; there is no growth of crystals of mica at all angles and in all directions, no criss-cross structure, no rosettes and sheaves, and no sign any- where of crystallization of chlorite. Neither do we ever see any trace of the amorphous, or semi-amorphous, and speckly material passing upwards into definite mica, etc., which I have pointed out as so frequently characteristic of rocks which have recrystallized under contact-action. Nor do we see in such rocks any trace of biotite or other special minerals which we know so well in contact-rocks. Yet all these things which we may thus find to be absent from some most ancient sedimentary rocks after they have had every allowance of time, dynamic action, and depth-conditions, we see can be pro- duced in similar materials, almost instantly, as it were, by the action of a relatively insignificant amount of igneous magma intruded among them; the evidence in the special case before us being quite beyond the possibility of confusion or question, as to the fact that these effects are wholly due to the intrusion and to nothing else, and thus much simpler and clearer than often is the case in granite areas. These observed facts, and the considerations arising out of them, duly weighed, seém to lend a reasonable degree of probability to the conclusion I have suggested on other occasions, viz., that so DECADE IV.—VOL. Y.—NO. III. 9 130 W. M. Hutchings—Rocks of Great Whin Sill. far as our present actual knowledge goes, there are structures and mineralogical developments which, whenever we see them, even in moderate degrees of evolution, we are not only justified in ascribing to contact-metamorphism, but which we have not an atom of reason or evidence for attributing to any other cause, no other cause having as yet ever been proved to produce them; and certainly not dynamic action, as to which we can collect plenty of very clear evidence that it has failed over and over again to bring about even the beginnings of them, under the very circumstances which ought to be most favourable for its doing so. When we look at this matter quite calmly, it certainly does seem rather strange that the “blessed word” dynamometamorphism has been allowed to exercise such a spell over our minds in directions in which it can hardly be said to have ever made good its pretensions. Here were rocks of sedimentary origin, showing very great and striking mineralogical developments. They aiso showed beyond question that they had undergone great dynamic action. Therefore the latter was the cause of the former. In how many cases has there been but little better evidence than this to support its all-embracing claims, which were made to explain everything without proper proof! And at the same time we have, all around us, examples of the fact that what dynamic action has been asserted, ~ but not proved, to do, is done not only by every great intrusion of granite or other igneous rock, but by even quite small intrusions also. Let a great area of sedimentary rocks be altered by the action of igneous masses which we cannot see; then let powerful dynamic action follow, and there we have at once a fine example of the marvellous recrystallization and formations of new minerals which dynamic metamorphism has brought about, shutting our eyes to other cases in which even more intense action, on similar materials, has effected practically nothing of the sort. If we take simply what we at present know, and can prove over and over again, and separate it from what is certainly not at all proved, no matter how strong the a priori evidence may sometimes appear, it would seem to be quite reasonable if we were to regard certain microscopic structures of altered sedimentary rocks as probably indicating that the alteration took place under the influence of contact-metamorpbism, no matter whether we can actually see the igneous rock concerned in it or not. On a similar line of reasoning from what we know, we might also draw the same inference from the development of certain minerals in such rocks, not only the specially so-called “contact-minerals,” but others as well. Thus, the presence of undoubtedly newly-formed biotite in- altered shales and slates should point the same way, till we have some evidence that any other process known to us can be proved to have the power of producing it. And it might even not be going outside the safe ground of induction if we were to include ~ very highly developed and individualized muscovite, and certain forms of chlorite, under the same head. ‘)f these several points, that of structure certainly appears to be Notices of Memoirs—Lyman on Compass Variation. 181 the most important, and the safest on which to rely, whenever we find it. But we know that dynamic action may have more or less completely effaced this structure, and in a great number of cases has done so. We know on what lines this effacement proceeds, and with what sort of new structures it replaces those it has modified or destroyed. It is, however, not uncommon to find that, even in greatly affected “dynamic” areas of this description, the action has not embraced the whole of the rock, and from among rolled-out, sheared, and puckered schists, may come specimens showing, more or less per- fectly, the contact-structures which we seem to have good grounds for always recognizing as such. | ISPFOQLwGwEHS) (Ougy Ive yMa@alisytS Compass VARIATION AFFEOTED BY GEOLOGICAL STRUCTURE IN Bucks anpD Montgomery Countiss, Pa.’ By Brensamin Smite Lyman. HE Journal of the Franklin Institute, October, 1897, contains an interesting paper by Mr. B. Smith Lyman, formerly State Geologist to Japan, describing a remarkable coincidence between the axis of a set of curves of magnetic variation in Bucks and Montgomery Counties, Pennsylvania, and a great deep-seated fault in the New Red strata below ending westwards in the axis of an anticlinal fold. Both the curves and the fault are shown on an accompanying map. From this paper we extract the following passages :— The magnetic curves were mapped some years before the beginning of the recent Geological Survey, that for the first time fully proved the peculiar structure ; but the curves had no influence whatever in the interpretation of the geology, and the correspondence was not perceived until long after the geological map was printed. The magnetic map was made about the year 1883, by the Water Department of the city of Philadelphia, for use in its excellent topographical survey of the Perkiomen and neighbouring valleys under Mr. Rudolph Hering. The map records the results of a number of determinations of the magnetic declination made by the Water Department itself and by the Coast Survey and by other observers, and curves of equal declination were drawn for every tenth of a degree. The curves are so extremely at variance with the simple, nearly straight lines of earlier, less detailed maps, as either to show extreme confidence in the accuracy of the observa- tions, or perhaps even to excuse a suspicion of the possible incorrect- ness of the curves in some way, especially in view of the acknowledged want of precision of some of the observations, and the absence of any obvious topographical or other occasion for such 1 Reprinted from the Journal of the Franklin Institute, October, 1897. | Mining and Metallurgical Section: Inaugural Meeting, held April 28th, 1897. 182 Notices of Memoirs—Lyman on Compass Variation. great irregularity. But the curves are in the main beautifully confirmed and thoroughly vindicated by the underground geology. The striking feature and dominant peculiarity of the curves is a very strong bend convexly north-eastward near New Hope and Lambertville, on the Delaware; but gradually changing towards the west, so that the curves near Shwenksville and Boyertown point still more sharply south-eastward. The axis of the bend in the curves is, then, itself greatly bent, nearly to a right angle. The Geological Survey of the two counties, begun at the end of 1887, has proved beyond a question the existence of an enormous fault, of about 14,000 feet, in the rock beds, almost precisely on the line of the Delaware River end of that magnetic axis, and following the same course past Doylestown, gradually dying out, and west of that town turning north-westward, passing north of Shwenksville, disappearing there as a fault, but continuing as a sharp anticlinal to the border of the New Red and of Montgomery County, 5 miles north-east of Boyertown. The geological structure of the map of 1893, published by the State Geological Survey, was drawn without the least reference to the magnetic curves, and, indeed, without any knowledge at that time of the slightest correspondence between them and the geology. The geological map gives the direction and amount of the dip at — a couple of thousand points, amounting to a complete demonstration of the structure, and to a full proof of the situation and extent of the fault and of the sharp anticlinal into which the fault runs. The topography also given on the same map shows that there is no one strongly-marked ridge following the course of the axis of the magnetic curves. Indeed, there are more decided topo- graphical indications in the way of long, rather high ridges in other directions. Furthermore, the form of the outcropping rock beds, sedimentary or igneous, does not correspond in any degree with the magnetic curves. Moreover, some light is perhaps thrown upon the obscure subject of terrestrial magnetism. It is true, the nature of the relation between the magnetic and geological phenomena is not so easily determined; but it seems to become certain that the internal structure of the earth’s crust has an important influence upon terrestrial magnetism, even if it be not in any degree its first cause. Terrestrial magnetism and its changes have sometimes been con- sidered explainable by solar influences alone, no longer by direct action of the sun as a magnet, but by the sun’s heating the atmosphere or the earth’s crust. The present phenomena seem, however, to point to more strictly terrestrial processes as the true. cause, and to suggest that the solar influence may partly at least be exerted through the attraction of gravitation as well as through heat. The enormous and locally unequal strains produced by the contraction of the earth’s crust in cooling would be particularly” liable to be affected by the presence of a deep fault or by a sharp anticlinal. Such lines would be places where the crust has yielded and is readier to yield, and consequently where the strain has ai pees! Hae li ~- 7 : 7 2: Bae oo, me bs ce £ > iat Td | Ae “AI ‘Id “A ‘I8A ‘AI 9pvooq ‘9681 “OVIN “10U4) Reviews—J. G. Millais—British Deer. 1338 been to some extent relieved and is less. The recent occurrence of earthquakes along the New Jersey end of this very fault-line shows that the resistance there is less, and that the remaining strain must likewise be less. On such a comparatively weak yielding line the rock beds in readjusting themselves, even where ‘there is no violent earthquake, must occasion a certain amount, not only of strain, but of friction and heat that might give rise to electrical currents. A decided magnetic effect, too, has sometimes been observed to accompany earthquakes, and in some cases to precede them. In like manner, the strains and yielding or readjust- ment that may be occasioned by the attraction of the sun and moon might apparently cause electrical currents; and, in fact, magnetic disturbances have been found to correspond, like tides, with the place of those heavenly bodies. Again, the broken or arched form of the rock beds may permit at least a temporary local ‘variation in the temperature of the crust, as affected by the earth’s hot interior, that could occasion electrical earth currents. Terrestrial magnetism seems, then, to arise not only from the manifold action of the sun’s heat upon the air and the earth’s crust, but from the internal movements of the crust and from the tidal effect of the sun and moon upon the air, ocean, and solid earth. The author does not admit that the magnetic curves could have been produced by any known deposits of iron-ore or trap, near or distant ; comparing such an idea to the ancient Oriental tales of the loadstone that drew men’s boot-nails, or the seaside mountain that pulled the bolts out of ships’ sides. He adds :—‘“‘ Deposits of magnetic iron-ore, though differing much in magnetic force, seldom directly affect the most delicate magnetic needle at a distance of more than a few hundred feet.” 154 dH WA de den WW Se British Deer anp THEIR Horns. By Joun Guitie Mitzats, ¥.Z.8., ete. With 185 text and full-page illustrations, mostly by the Author, assisted by Sidney Steel, two by H. Roe, and photographs; and a series of unpublished sketches by Sir Edwin Landseer. Imp. 4to; pp. xviii and 224. (London: Henry Sotheran & Co., 37, Piccadilly, and 140, Strand, W.C. 1897.) (PLATES III AND IV.) R. MILLAIS is already favourably known to the public as the author of ‘‘Game-Birds and Shooting Sketches” and “ A Breath from the Veldt,” both rich in illustrations. Although a thorough sportsman, and, like his father, the late Sir John Everett Millais, Bart., R.A., a born artist, Mr. John Guille Millais com- bines with these qualities sufficient of the true naturalist and palezozoologist, to lead him in his “History of British Deer and their Horns” to enter upon a brief account of the ancient types of deer which inhabited these Islands in prehistoric times, 134 Reviews—J. G. Millais—British Deer. and whose skeletons and antlers preserved in the British Museum (Natural History), Cromwell Road, or in other kindred institutions, now form their only record. Many of these Mr. Millais has sketched with commendable fidelity. It is difficult to separate the extinct Alces latifrons, found in the Cromer Forest Bed and at Happisburgh and Corton, and on the Dogger Bank, from the living elk (Alces machlis) found subfossil at Cleveland, Yorkshire, and in about thirty-one English, Scotch, and Irish localities, and which still survives in Norway and in Canada. To the same northern category also belongs the reindeer (Rangifer tarandus), which is recorded from more than eighty localities in this country, is still living in Northern Europe, Asia, and America, and is believed to have survived in Caithness until the middle of the twelfth century. Of fossil varieties of the true deer, Cervus polignacus, C. Brownii, and ©. Savini, little need be said. They are forms closely related to the existing fallow-deer (C. dama). Cervus Dawkinsii and C. Fitchii are most probably related to the elk (Alces machlis); C. verticornis, C. tetraceros, and C. Sedgwickii are all from the Norfolk Forest Bed at Cromer, Bacton, and Kessingland. C. tetraceros has the beam more or less straight, with the tines rounded, simple, and springing all from one side of the beam. C. Sedgwickit has the beam flattened and more — arched, and the tines, although upon the same plane, are flattened and branched. There is yet another extinct deer (the Cervus giganteus), the largest of all the Cervidee, whose remains have been obtained not only in great abundance, but in so perfect a state, in Ireland that entire skeletons are to be seen in many of our Museums, whilst the antlered skulls adorn many noble residences in England, Scotland, and Ireland. Formerly known as “ Megaceros Hibernicus ” or as ‘‘the gigantic Irish elk,” yet it is in no wise related to the elk, although frequently spoken of as such. It is in every respect a true deer, and in many of its characters (save that of size) not unlike our existing fallow-deer. When it is stated that these deer frequently measure 9 feet across the antlers, the weight of which is as much as from 80 to 90 1bs., one is astonished at the amount of vital energy in such a beast as would enable it to throw out year after year such a mass of osseous matter in the short period of four months, for the horn- growth of the Megaceros doubtless followed the same rules as those which govern the horn-growth of other deer to-day. “In the British Isles this deer seems to have been most numerous in Ireland, where remains are found below all the peat-bogs in the lacustrine shell-marl. In County Limerick the greatest number of heads has been dug up, notably in the extinct Lake of Loch Gur, where literally hundreds of them have been unearthed. In 1875, Mr. R. J. Moss made excavations in the bog of Ballybethag, — Y miles south-east of Dublin, and during the summers of 1876-77 twenty-six heads and three complete skeletons were procured. Below the great bog, in the vicinity of Tullamore, is another -Reviews—J. G. Millais—British Deer. 135 productive district, as is also the margin of Loch Derg (Co. Galway) and Killowen (Co. Wexford). “The first tolerably perfect skeleton of Megaceros was found in the Isle of Man, and was presented by the Duke of Athole to the Edinburgh Museum in 1820.”! In 1896 a second, nearly perfect, example of Megaceros was obtained near Poortown in the same island. _ (See p. 116.) In England the remains of this great deer are rare. The first skull and antlers were dug out of the peat-moss at Crowthorpe in Yorkshire. About twenty-nine localities are recorded, but the remains are exceedingly fragmentary. In France its remains are said to have been found near the foot of the Pyrenees ; in the valley of the Oise it has been found associated with the mammoth, the rhinoceros, the musk-ox, the reindeer, and hippopotamus. There is one skull with imperfect antlers in the British Museum from as far east as the Government of Orbowschen, in Russia. Complete heads and antlers have recently been found in the south- west of Scotland. There is good evidence for the conclusion that after the great deer had spread into Ireland, and probably long before its extinction in this country or in Western Europe, Ireland must have become isolated from England, and during a long succeeding period the Cervus giganteus lived and flourished in that island, and was neither exterminated there by prehistoric man nor by any of the Carnivora, but by a great and gradual change which took place in the climate of that country. This change, in which Scotland and a part at least of England also partook, was an increase in cold and a settled humidity of climate, tending to a great growth of peat, which in time filled up the former extensive fresh-water lakes, once so abundant, and injuriously affected the forest growth over large areas of the country. With this change the great Irish deer died out; but its remains show that it was living there before the growth of Sphagnum or bog-moss had taken place, for they rest in the shell-marl beneath the peat. This shell-marl is really composed of the accumulated deposit of dead and decomposed shells of fresh-water Unio, Anodon, and Limnga, so that it repre- sents a long and tranquil period of time during which conditions were favourable to forest growth, and consequently to the deer and the other denizens of the woods and waters. We give a diagram-sketch by Mr. Millais of the way the Irish deer occurs beneath the peat (see Woodcut). The man who searches for the megaceros-heads uses a rod about 25 feet in length. First of all he takes a survey of the bog, and from long experience knows where to commence his probing in what seems a likely spot. Should the iron strike stone or gravel, he knows by the gritty feel, whilst horn gives a dull thud, and by turning the rod round and round the searcher is able to tell of what nature is the substance he has struck. 1 This skeleton from the Isle of Man was described by Baron Cuvier in his ‘« Ossemens Fossiles,’’ tome iv, pl. viii, fig. 1. 136 Poni . G. Millais —British Deer. How THEY HUNT THE [IRISH DEER AT THE PRESENT DAY. Showing mode of finding the heads, and the strata in which they are generally imbedded. 1. Peat (top layers), 3 feet. 2. Gravel, 6 inches. 3. Peat (lower layer with trees), 3 feet. Layer of oak-leaves, 3 inches. . Blue clay (mixed with shells), 6 inches. y Lacustrine shell-marl (with remains of Megaceros, and fresh-water mollusca), 3 feet. . Blue clay, mixed with subangular stones. (Thickness shown in diagram, about 12 feet. Many of the peat-bogs are far thicker.) Reviews—J. G. Millais—British Deer. 137 Many a time a day’s digging only produces a head not worth lifting, owing to its being broken in many pieces, or perhaps it is only a dropped antler. As to the causes which have led to the extirpation of the larger mammalia, we do not think it necessary to postulate a universal cause or agent of destruction before which all the big herbivora were swept away. Professor Owen long ago pointed out that the large mammals were always the first to suffer from floods or from droughts; events which happen most frequently within the tropics, but which may occur occasionally in almost any country. Nor can we look at the accumulated-results of subaerial and diluvial action, especially in such an extensive region as Argentina, without perceiving that zolian agencies—wind-storms, dust-storms, rain-storms, and floods—acting on the Sierras and higher plateaux for thousands of years, have led to the gradual accumulation of those vast masses of fine material which have built up the great Pampean for- mation, while along the course of the great alluvial valleys cut through its deposits by the rivers flowing from the north, lie buried many hundreds of giant Mylodons, Megatheria, and Glyptodons, once the denizens of the wooded region of Central South America. The discovery of thousands of remains of great wingless birds in the superficial deposits of New Zealand has no connection whatever with the destruction of giant Edentates in South America, nor with giant deer in Ireland, save that man the destroyer was for a long period absent from the scene, and the Dinornis and its kindred enjoyed for many centuries undisturbed possession of their island- home, the Harpagornis, a large hawk, being the only bird of prey, and no Carnivora having reached New Zealand except seals. With man came the hunter-element (see Plate III), and the “fire-stick”” ; and the forests, being not unfrequently accidentally lighted, the affrizghted game (whether deer or Moas) fled towards the water to escape from the fire, and met their death by drowning in the morasses they attempted to ford. In Australia the destruction of the large Marsupialia was probably not unfrequently caused by drought, which has so often proved fatal to the flocks and herds of the squatter in our own time. ‘There, too, also local floods often prove, as in South America, most destructive, although of short duration, and these may even in a single night affect a vast area of country. Mr. Millais has figured many fine antlers of Trish deer, notably those forming part of the complete skeleton of Cervus giganteus in Sir Edmund Loder’s Museum at Leonardslee (pp. and 9); and four heads on p. 19, from Loch Gur, from the Royal Dublin Society, from County Waterford, and from Limerick, which illustrate remarkable divergences in mode of growth. The antlers in these specimens have lost their original crescent-form and become too much flattened out. This may either have been caused when the antlers were softened from lying in the bog, or afterwards. when mounted, they have bent downwards by their own weight. Originally they were certainly more V-shaped. On pp. 14 and 15 are given 138 Pon peat . G. Millais— British Deer. two views of a splendid head and antlers from near Tullamore, Ireland, in the possession of the Duke of Westminster, in which the palms are enormously developed. There are remains of 19 individuals in the British Museum, comprising 4 complete skeletons, 38 antlered males and 1 of a (horn- less) female; 2 skulls of hinds from Naull, Co. Dublin; 8 skulls with antlers which have no special locality save “ Later Tertiary deposits, Ireland”; 1 head from Red Bog, Dunshaughton, Ireland ; 1 skeleton from Axe Corey, Co. Wexford; 2 skulls of males with shed antlers from the Dogger Bank; and 1 head from Russia. The remaining types of British Deer—the “Red-deer” (Cervus elaphus) ; the “ Fallow-deer”’ (Cervus dama); and the “ Roebuck ” (Capreolus caprea)—are so well known in the living state, that they would appear to have little claim on the attention of the paleontologist. When, however, we study the Pleistocene deposits of our Island, we are led to find that even these denizens of our parks have a more or less remote geological history, not wholly devoid of interest. Taking the red-deer as the typical representative of a great group of Cervide, which are spread over Kurope, North Atrica, Asia (north of the Himalayas), and North America, we find these are mainly characterized by the conformation of the antlers. In this type the. brow- and bez-tine are both present ; the beam is nearly cylindrical, subdividing into two or more points at the summit. The group of allied species would include the red-deer (Cervus elaphus) ; the Canadian wapiti (C. Canadensis); C. maral; the Thian-shan deer (C. eustephanus or C. Leudorfi) ; the Amurland deer (C. wanthopygus) ; C. corsicanus; the Barbary deer(C.barbarus) ; and possibly also the Hangul or Cashmir deer (C. Kashmirieusis). Our brickearths, cave-deposits, and peat-bogs also yield evidence of deer-remains far larger in size than those now living, so that there can be little doubt that, ancestrally at any rate, the great. red-deer and the wapiti were closely related. In Flower & Lydekker’s great work on Mammals, living and extinct, stress is laid on the absence of a cup at the surroyals, as distinguishing the wapiti from the red-deer; nevertheless, many red-deers’ antlers have no trace of the cup whatever. Indeed, after studying a long series of them one cannot help feeling that the richly crowned antlers of certain red-deer from the peat, notably the pair obtained from the bed of the River Boyne at Drogheda, Ireland (part of the Egerton Collection), owe their unusual development to specially favourable environments and abundance of food, as exemplified in the collection of magnificently crowned heads preserved in the Castle of Moritzburg by H.M. the King of Saxony (sixty of the choicest of which have been figured by Dr. A. B. Meyer, Director of the Royal Zoological Museum in Dresden, in two volumes, royal folio, one vol. published in 1888 © and one in 1887). In Mr. Millais’s work (p. 23) he writes: ‘The Warnham deer are second to none in this country in the matter of body and horn. Reviews—J. G. Millais—British Deer. 139 Their origin, however, is quite recent, and even after the introduction of the Stoke deer, by which the herd was strengthened some years ago, they were in no wise remarkable until the late Mr. F. M. Lucas took them in hand and began a series of experiments with a view to improving the pasture—about 250 acres in extent. Every alternate year he dressed the land with bone-dust, the effect of which soon made itself felt. The nutrimental qualities of the grass seemed to be improved 70 per cent., yielding exactly what was wanted for fattening and horn-growing. Half the park is reserved for hay, so the red-deer, which number about 100, have no great extent of ground to range over and very little winter-feeding. Neverthe- less, they thrive and have continued to improve steadily since 1884, when the dressing was first tried, and at the present time a four-vear-old Warnham stag is better than an adult animal in most other English parks.” (See Pl. IV.) Mr. Millais gives on p. x an illustration of a pair of antlers grown by a stag living on an open heather-covered mountain (Castlewellan, Ireland), with but little wood-shelter at the base. Two other heads on pp. 1380-1, one from Braemore forest, Ross-shire, the other from Eskdale, and the pair of fossil antlers from Bakewell, Derbyshire (figured in Pl. I], Guor. Maa., Feb. 1898), may serve to illustrate the simpler form of red-deer antlers in which the cup and highly-branched crown are but little developed; the beam may be of great strength, but it and the tines are well-formed, symmetrical, and well-adapted for offence and defence. This type appears to be a mountain-dwelling, hardy, fighting stag. The crowned antlers with such a large number of points (often from thirty to forty) are found in the peat-deposits, and belonged to stags which must have been as well-fed in a natural state as are those in Mr. Charles Lucas’s park at Warnham Court, or in the German deer-forest of the King of Saxony at Moritzburg. Clearly, in these latter instances, the excessive richness of the growth of antlers is a luxury which would only be found exceptionally in a wild state, and must require special care for its proper maintenance even in a park-herd (or under domestication).* Passing over the fallow-deer as affording less geological interest, we come lastly to the little roebuck, Capreolus caprea, a small form of deer and a truly wild denizen of our woods, being found in Dorsetshire, Hampshire, and Essex, in the south, in the west in Wales, away north to Scotland, and widely over Europe and Western Asia. The male is somewhat over 2 feet in height at the withers, of a dark reddish-brown colour in summer, with a white patch on the rump. The small antlers stand close together at their base, have a short rugged beam, rising vertically, then bifurcating, the posterior branch again dividing. The roe-deer dates from the 1 Mr. Lydekker, F.R.S., informs the writer that there is a magnificent series of red-deer antlers to be seen in the Hall of Hampton Court Palace, where they may have been since the days of its founder, the famous Cardinal Wolsey, in 1026, or since its rebuilding by Wren in 1690. 140 Reports and Proceedings—Geological Society of London. Pliocene period, and is doubtless related to several other small Cervide, some of which, like the Chinese water-deer, are hornless forms. We must now part with Mr. Millais, but we do so with regret. We cannot imagine a more charming book for the Library table of a country house than his “ British Deer and their Horns.” et Ores AlN» ROC frp sie Ss. GroLogicaL Soorrry oF Lownpon. January 19, 1898.—Dr. Henry Hicks, F.R.S., President, in the Chair. The following communications were read :— 1. “On some Gravels of the Bagshot District.” By Horace W. Monckton, Hsq., F.L.8., F.G.8. The author refers to his papers on Gravels South of the Thames published in the Quart. Journ. Geol. Soc. for 1892 (p. 29) and 18938 (p. 808), and gives some additional details. He suggests that the occurrence of stones which have been very little rolled or waterworn in gravels at certain localities affords evidence of the presence of ice in the water by which those gravels ' were deposited, and that the position of some sarsens which he describes is due to the same agency. He gives details and exhibits photographs of a number of sarsens which he has seen in siti. 2. “On the Occurrence of Chloritoid in Kincardineshire.” By George Barrow, Esq., F.G.S. (Communicated by permission of the Director-General of the Geological Survey.) The rock containing the chloritoid was first found in sitd at the entrance to the little gully at the head of Friar Glen Burn, near Drumtochty Castle. It has since been observed at many places along a belt of country extending from the coast north of Stone- haven nearly as far as the North Esk. The rock is easily recognized by the presence of numerous white spots, which are always present and are larger than the chloritoid. The chloritoid and the spots vary in size, being largest when the rock is most crystalline (a schist), and smallest when it is least crystalline (a slate). The mineral appears as minute glistening scales in the schist, but in the slate it can be recognized only with the aid of the microscope. The optical characters are described, and shown to be identical with those of the mineral from the Ile de Groix, and with those of the ottrelite from Ottré and Serpont. An account of the methods adopted to obtain a pure sample is given. Several analyses were made, and it was proved that as the purification increased the analyses approximated more and more closely to the analysis of the mineral from the fle de Groix. The final result was as follows :— Obituary—Professor Dr. Oscar von Fraas. 141 SiO ahs aes acon ah. 26100 AT OS ores ie oe eet ee 0-05) HeOr fel nas) Cee aL 50 Hes Oth = ah Way Pa ee ane OLD Mg Ofer ssc) aa eR Thossonsionition ay ames 6:00 Total Af han oat ees The author discusses some of the published analyses, and suggests that many of the discrepancies may be due to impurities in the material analyzed. : GIG 5)1544 SISO rN Da aan (Ojash- THE AGE OF THE RAND BEDS. Srr,—In the Gronocicat Magazine, 1897, p. 549, Mr. W. Gibson states that I have obtained fossils of doubtful Carboniferous age from a dolomite associated with the Gat’s Rand Beds. I am not aware of having made such a statement, and it certainly does not occur in the paper alluded to (‘The Occurrence of Dolomite in South Africa,” Q.J.G.S., vol. t, p. 561). In fact, so far as I am aware, no fossils of any kind have hitherto been discovered in the Dolomite of this country. Davip Draper. JOHANNESBURG, Dec. 31, 1897. THE OCCURRENCE OF PLACOPARIA IN THE SKIDDAW SLATES. Str,—In the course of my work on the Graptolite Fauna of the Skiddaw Slates I have come across two specimens of the trilobite Placoparia. No mention of this form is made by Postlethwaite and Goodchild in their paper on the “ Trilobites of the Skiddaw Slates ” (Proc. Geol. Assoc., vol. ix, p. 455), and as it is known to be characteristic of a definite horizon in other localities, it seems worth while to place on record the occurrence of this genus in the Lake District. The specimens in question come from two different localities, Outerside and Ellergill, and are in the Woodwardian Museum. The Ellergill specimen is a recent gift from Professor H. A. Nicholson. GertruDE L. Ewes. Woopwarpian Mvuszeum, CamsrinGce, February, 1898. @aS tere OPA enys= OSCAR FRIEDRICH VON FRAAS. Born January 17, 1824. Diep NovEemMBer 22, 1897. We regret to announce the death of the veteran geologist Dr. Oscar von Fraas, of Stuttgart, Director of the Royal Wiirtemberg Museum of Natural History. He was born at Lorch, in Swabia, in 1824, and after his ordinary education at school he proceeded to the University of Tiibingen. ‘There he devoted special attention to 142 Obituary—Lieut.-Col. C. Cooper- King. . theology, with the intention of entering the Church; but he was at the same time also deeply interested in natural science, and he attended the lectures of Quenstedt, who filled him with enthusiasm for geology and paleontology. He worked hard in collecting fossils and making geological observations in Swabia, and when he had the opportunity of spending a year in Paris, in 1847, he attended the lectures of D’Orbigny and Elie de Beaumont at the School of Mines. On returning to his native country, Fraas followed his theological profession, and from 1850 to 1854 he was pastor of Laufen a. d. Eyach. In 1854 he became Conservator of the Department of Mineralogy and Paleontology in the Royal Wurtemberg Museum at Stuttgart, an office which he held until a few years ago, when, on the retirement of Dr. von Krauss, he succeeded to the Directorship, and left his son, Dr. Eberhard Fraas, in charge of the minerals and fossils. In the course of his official labours, Dr. Oscar von Fraas not only made the Stuttgart collection one of the finest in Hurope, and enriched it with Swabian fossil batrachians, reptiles, and — mammals, many of which are absolutely unique; he also published popular writings to interest the people in his work, and carried on a long series of researches, of which the results appear in more than sixty papers and memoirs. Most of these relate to the geology, fossils, and prehistoric archeology of Wiirtemberg ; but some also recount his experiences in the East, which he visited in 1864-6, and again in 1875. He paid special attention to the geology of the Lebanon ; and the scientific results of his journeys through Syria are collected in a small volume entitled ‘“‘ Aus dem Orient,” which was published in two parts (1867 and 1878). Among his larger memoirs, those on the Miocene Mammalian Fauna of Steinheim (1870), and on the armoured reptile Aetosaurus from the Swabian Trias (1877), are especially important contributions to knowledge. Dr. Oscar von Fraas was elected a Foreign Correspondent of the Geological Society of London a few days before his death. LIEUT.-COLONEL CHARLES COOPER-KING, F.G.S. Born Frespruary 4, 1843. Dizp January 16, 1898. CHartes Cooprer-Kine, Lieut.-Colonel Royal Marine Artillery (retired), died at his residence, Kingsclear, Camberley, Surrey, on the 16th of January, 1898, aged nearly 55 years. The only son of Major U. H. King, R.M., Light Infantry, he was born at Plymouth. He was at school there until the end of 1859, passed into the Royal Marines as a Marine Cadet in January, 1860, second on the list, and joined H.M.S. “Excellent.” He passed as a Second Lieutenant R.M. at the Royal Naval College, Portsmouth, first on the list (1862); and, recommended for the R.M. Artillery, he was gazetted at Fort Cumberland. In 1864, he was appointed to command the detachment of Marines on H.M.S. “Scylla” in the- China seas and Japan. He was promoted to First Lieutenant in 1865; and rejoined headquarters (Hastney) in 1867. He passed (fourth) into the Staff College, July, 1868; and in August he Obituary—Lieut.-Col. C. Cooper- King. 143 married Harriet, daughter of the late C. V. Garrett, of Southsea. Passing out of the Staff College, first on the list, and specially recommended, he went through the usual course of study and practice in regimental duties at Aldershot, and the long course of gunnery at Woolwich and Shoeburyness (1871). He was appointed Instructor of ‘actics, Administration, and Law at the Royal Military College at Sandhurst, 1872; and was Professor of the same subjects 1878-1885. His promotion as Captain dates November, 1875, and Major by Brevet, 1879. He retired from the Service February, 1886; and devoted his time and energy as a military instructor or “coach,” preparing subalterns of the ‘Militia for commissions in the Army. He leaves two daughters and five sons; two of the latter are Lieutenants in the Army. After the systematic study of geology and chemistry was eliminated from the curriculum at the Staff College, and the professorships thereof had ceased, Colonel C. Cooper- King succeeded Major Mitchell as Lecturer on Geology in 1886. Dealing also with such other branches of Natural Science as the officer- students could find time to study, his synopsis of these lectures on ‘Applied Science” embraced not only the land, but water (fresh and salt), air and weather, magnetism and electricity, as well as food and forage. Colonel Cooper-King drew a large class to geology, both in the lecture-room and the field; for, being a military expert himself, his explanations of the science in relation to military tactics and battlefields were well appreciated. Whether on the blackboard or on paper, his apt and facile illustrations of geological conditions and natural-history facts were very acceptable to his students and his scientific friends. Always observant, and ready with pen and pencil, his notebooks were rich with reminiscences of places and people, visited or met with, at home and abroad. In spite of frequent illness, due to rheumatism and heart-failure, his energy spurred him to persist as a hard worker, whether in the study on literary matters, in the field as military correspondent, or in his class-room among military students. Many of his friends in the Army remember with pleasure, and often with gratitude, the advantages they received from his teaching, as private instructor or at college; and, indeed, he was always ready to help, both cadet and officer, with advice and solid information. He was an Assistant-Hxaminer in Geology, Geography, and Physiography for the Science and Art Department (South Ken- sington) and the Civil Service Commission for twenty years. As literary work, we may notice his books—‘‘On Map and Plan Drawing,” “ History of Berkshire,” “George Washington,” “The British Army,” and “The Story of the British Army,” the last- mentioned lately published. He was Hditor of the “ Great Campaigns in Europe,” and for some time of “The United Service Magazine.” Reviews, notices, and miscellaneous pieces by C. Cooper-King are scattered in different periodicals. In his ‘‘ History of Berkshire” (HE. Stock, London, 1887), a good 144 Obituary—Lieut.- Col. C. Cooper- King. knowledge of geology underlies his sketch of the county and description of the ways and doings, not only of prehistoric man in the region, but of the many events in historic times during the conquests and civil wars of Berks. The natural features, which have had an effect in the development of the county since the first nomad lived and fished along the banks of the Thames down to the time in which we live, are carefully considered. We have here a sketch of the evolution of the county, in its races, its homes, fortresses, arts of life, domestic and military ; and in its ecclesiastical, military, municipal, and civic relations. In this, too, his antiquarian knowledge gave his story vigour and accuracy. The ancient camps and earthworks were ably elucidated in the Transactions of the Newbury District Field Club, of which he was a worthy honorary member. His clear and succinct account of the Stone Implement Station in Wishmoor Bottom, near Sandhurst, Blackwater, and Camberley, with a good plan and an explanation of the structure of the ground, is published in the Journal of the Anthropological Institute, vol. 11, No. 6 (January, 1873), pp. 865-872, pls. xx and xxi, Also noticed in the Brit. Assoc. Report for 1872, Sections p. 190. Colonel Cooper- King was elected a Fellow of the Geological Society in 1872. In 1875, he communicated to that Society a paper, written in conjunction with his friend IT. Rupert Jones, on some newly exposed sections of the “‘ Woolwich and Reading Beds” at Coley Hill, Reading, Berks (Quart. Journ. Geol. Soc., vol. xxxi, pp. 451-457, pl. xxii). The features then exposed were correlated with those of neighbouring sections described by Buckland and Rolfe many years ago, and more lately by Prestwich and Whitaker. Two zones of clay-galls were particularly described, and the beds and levels from which these balls of clay (and ochreous nodules) were derived were carefully indicated. Together with the same friend, Colonel C. Cooper-King had long studied the conditions and characters of the Bagshot Sands; and his acute observation and thoughtful conclusions must be regarded as having given value to the papers on the Bagshot district published in the Proceedings of the Geologists’ Association, vol. vi, 1880-81, pp. 319, 429, ete. His high grade in college work indicated his mental capacity, strong will, and power of endurance; and his subsequent career showed his versatility and broad intellectual grasp, also his determination to use his gifts for the benefit of his country and especially of those around him. Thus a man of talent, of great capabilities, of high attainments, — and enormous energy, conscientiously and willingly exercising his” powers for the good of others, and working hard for the support of his family even to the last, has passed away, like a goodly fruiting tree torn away by the ruthless tide of a flooded river, - which will distribute the seeds in far-off places, where, like those previously shed, they must produce good results. tera a) THE GEOLOGICAL MAGAZINE NEW ObRIES. «DECADE SI Vege VOL. IV: No IV.—APRIL, 1898. Ore Garay Arie, AS ana Gases pent hemi , I.—Tue Harttest Grotocica, Mars oF ScoTLAND AND JRELAND. By Professor J. W. Jupp, C.B., LL.D., F.R.S., V.P.G.S., etc. fP\HE first geological map of Scotland has a history not less interesting than that of Smith’s famous map of England; seeing that what Smith accomplished, single-handed, for the southern part of Britain, John Macculloch did, with the same independence of all extraneous aid, for the northern half of the Island. Smith’s fame has happily been long since vindicated; but, owing to a variety of circumstances, Macculloch has never received full credit for his grand work; on the contrary, his fair name and even his veracity have been too often cruelly aspersed. Macculloch, though of Scotch descent, was born in the Channel Islands, and patented first in Cornwall and afterwards as a medical student in Edinburgh. He was an excellent chemist and mineralogist, and brought to the study of geological problems an amount of exact scientific knowledge rare in those who at that day turned their attention to the subject. Commencing life as an Army-surgeon, he in 1803, when thirty years of age, was made Chemist to the Board of Ordnance, though the appointment did not prevent him from practising privately as a medical man at Blackheath from 1807 to 1811. In the latter year, however, he gave up medical work and was sent to Scotland to make inquiries as to the best rock suitable for powder-mills. Suk sequently, a Commission was formed to ascertain what mountain in Scotland would prove most suitable for experiments similar to those carried on by Maskelyne at Schiehallien, to determine the earth’s density. In this way Macculloch was led to spend much time in travelling about Scotland and in studying the rocks of the country, and between the years 1811 and 1821 he each year devoted portions of every season to geological work in the North. In 1814 he received the appointment of “Geologist to the Trigonometrical Survey,” a post to which it had been proposed, as we have already seen, to appoint William Smith in 1805. John Macculloch was an original member of the Geological Society, and soon became one of the most active workers in it. His paper entitled “‘ Account of Guernsey and the other Channel Islands ” was the first which was honoured with a place in the Transactions of the Society, and many other valuable memoirs from his pen found DECADE IV.—VOL. ¥.—NO. IY. 10 146 Professor J. W. Judd—Earliest Geological Maps a place in succeeding volumes. Macculloch was the fourth President of the Geological Society, occupying the Chair from 1816 to 1818. In 1819 Macculloch published, in two volumes with an Atlas, his “Description of the Western Islands of Scotland, ‘including the Isle of Man, comprising an Account of their Geological Structure, with Remarks on their Agriculture, Scenery, and Antiquities.” The maps and sections of this work must be admitted to be: of extraordinary merit, when the imperfect topographical data at the author’s disposal are taken into account. His sections, illustrating the relations of igneous to stratified rocks, are of great value, and exhibit a very marked advance on anything of the kind that had ever been produced before. In 1826 Macculloch, who had collected a vast mass of information concerning the geology of Scotland, received a commission from the Lords of the Treasury to construct a geological map of the country. While he was thus employed, Macculloch received a regular salary from the Government, and, when the map was completed, it was engraved and coloured by the order and at the cost of the Treasury. Macculloch finished the field-work in 1832, and by the middle of 1834 the coloured map was ready for publication, and was, with accompanying memoirs, sent in to the Treasury. Unfortunately, however, various circumstances seem to have delayed the publication of the work. There being no Ordnance Map of Scotland at the time, Macculloch was compelled to employ the best private map which then existed—that of Arrowsmith— on which to insert his geological work. All who have endeavoured to do any serious geological mapping in Scotland, before the publication of the Ordnance Map, will sympathize with Macculloch in his disappointments—frequently verging on despair—in trying to adequately represent the geological structure of the country on such an imperfect topographical basis as that of Arrowsmith’s Map. Macculloch’s Geological Map of Scotland, which has recently been characterized by a very high authority as “perhaps the most remarkable achievement of the kind which up to that time had been accomplished by a single individual,” long remained almost unknown to and neglected by geologists. In 1851 Murchison referred to it as being “usually known as Macculloch’s Map,” and as being “so replete with errata that it would be a waste of time to attempt to enumerate them.” Macculloch belonged neither to the school of the Neptunists nor to that of the Plutonists, and not to take a side in those days of embittered controversy was in itself almost accounted a crime. In the accuracy of his mineralogical and petrographical knowledge, | and in his insistence on the importance of such knowledge to the field-geologist, he resembled the disciples of Werner; but by the accuracy of his description of the relation of igneous to sedimentary masses he did more than any other geologist to confirm and establish the principles so well shadowed forth by Hutton. When William Smith’s teaching of the value of fossils in classifying strata had spread, so as to meet almost universal acceptance among geologists of Scotland and Ireland. 147 south of the Tweed, Macculloch unfortunately found himself too old, too conservative, and too opinionated to accept the new views and to give them the welcome which they deserved. In spite of omissions and defects, which it would be easy to point out in any great pioneer work of the kind, Macculloch’s Map is a splendid production, and all subsequently published maps of the country have been based upon it. In one important respect the map, as finally published, did not do justice to Macculloch’s acumen and research. As is well known, he very early made out the true relations and age of the Torridon Sandstone and its infraposition to the Durness Limestone, in which lattér rock he was the first to detect fossils. Murchison and Sedgwick, however, vehemently opposed his views, maintaining that the Torridonian was nothing but Old Red Sandstone faulted down; and, in deference to their authority, Macculloch allowed his earlier and correct interpretation to fall into abeyance. If we seek for the causes of the neglect and injustice with which John Macculloch’s great work has been so long treated, they are not difficult to discover. In the first place, Macculloch, excellent mineralogist and able geologist as he undoubtedly must be admitted to have proved himself, was a man with many eccentricities of character—some of them not of the most amiable kind—and he became extremely unpopular during the later years of his life. In England, and especially among his earlier associates of the Geological Society, his contempt, strongly felt and often offensively expressed, for ‘“‘mere amateurs” could scarcely tend to make his company agreeable in circles where geology had been so widely cultivated by unprofessional workers. In Scotland, a supposed want of patriotism, indicated by a tendency to point out faults in the national character of the Highlanders, was a characteristic of Macculloch which made him the subject of the most rancorous attacks. Hmbittered by this isolation, and smarting under what he regarded as the undeserved neglect of his work and the unmerited aspersion of his character, Macculloch in some of his later works assumed an air almost of omniscience, and poured unmitigated contempt on all advances in geological science in which he had not taken a share. Macculloch died as the result of a carriage accident in Cornwall within a year of the completion of his map, and when it was only just on the point of being issued to the public. The earliest copies published bore the imprint “A Geological Map of Scotland by Dr. MacCulloch, F.R.S., ete., ete. Published by order of the Lords of the Treasury, by S. Arrowsmith, Hydrographer to the King”; and one such copy, originally the property of the late John Phillips, which came into my possession on the death of that geologist, I have handed over to the Geological Society, where it is preserved, side by side with the immortal work of Smith. But the title and description of the map were unfortunately merely engraved on a loose sheet to be pasted over the title of the topographical map; and, after the death of Macculloch, this description was, either by accident or design, usually omitted, and the 148 Prof. Judd—Geological Maps of Scotland and Ireland. geological map was issued as though it were the work of Arrowsmith. It must certainly be admitted that Macculloch’s strictures on the topography of the map were of such a character as to be only too well calculated to produce resentment in the minds of the publishers. From this sketch of the history of Macculloch’s Geological Map of Scotland, it will be seen that the first Government Geological Survey carried on in the British Islands was that of Macculloch. It is often said that the work of the Government Survey originated in the grant of £300 per annum made to De la Beche in 1832 to aid him in his labours in the South-West of England. But as we have seen, Macculloch was in 1814 appointed Geologist to the Trigonometrical Survey, and in 1826 was commissioned and paid by the Treasury to make a regular survey of the country ; and his map finished before the date of the first grant made to De la Beche was published at the national expense. ‘his first geological survey of Scotland by Macculloch has therefore just the same right to be regarded as a Government Survey as the second survey of the — country which was commenced in 1854 by the late Sir Andrew Ramsay, and is now being carried on by many workers with such admirable skill and energy. James Nicol’s Geological Map of Scotland—a work of great merit —which was issued about 1846, bears much the same relation to ~ Macculloch’s map that Greenough’s map does to that of Smith’s. Nicol’s work could not have been executed had not Macculloch’s— map been in existence, but the younger geologist was able from his own investigations, and by collecting and incorporating the work of many fellow-labourers in the same field, to make his map of Scotland a much more complete and trustworthy work than the original of John Macculloch. The Geological Map of Ireland by Sir Richard Griffith is well worthy of taking a place side by side with Smith’s England and Wales and Macculloch’s Scotland. Griffith, who, though born in Dublin, received his scientific training in London and Edinburgh, entered the Government service as an Hngineer and Surveyor in 1809, when only twenty-five years of age. For nearly fifty years he was constantly employed, travelling in all parts of the country, examining bogs, mines, and agricultural properties, carrying on the “ Perambulation or Boundary Survey of the parishes, baronies, and counties,” and making that assessment of the land so well known as ‘ Griffith’s Valuation.” In 1812, when Greenough laid the first draft of his Map of England and Wales before the Geological Society, he appears to have pressed upon the attention of his friend Richard Griffith the desirability of undertaking a similar work in Ireland, and in the summer of that year the first draft of such a map was made | by Griffith with the aid of notes supplied by Greenough. This | draft appears to have been continually added to and improved down | to the year 1821, when a proposal for its publication was made by the author in a letter to the Royal Dublin Society. Nothing, however, came of this proposal; and it was not till 1835, when Geol, Mag. 1898. 7 | Decade lV, VoLV. PLV. ahi ie tO et G.M.Woodwar d delet hth. West, Newman imp. alt sgyptian Fichinoidea. Decade IV. Vol. V.PL VL Geol. Mag. 189 6. imp . Newman ? West G.M.Woodward del. et lith. jan Hcehmoidea. ligypt Dr. J. W. Gregory—Egyptian Echinoidea. 149 Griffith was President of the Geological Section of the British Association at the Dublin Meeting, that he was able to publicly exhibit in a complete form his Geological Map of Ireland. In the following year, the Irish Government ordered this map to be reconstructed and engraved on a scale of one inch to four miles by the Board of Ordnance. Before the map could be issued, however, Griffith drew up for the Railway Commissioners a work entitled an ‘‘Quitline of the Geology of Ireland,” which contained a reduction of his map, with many of the details omitted. This small map, which was issued in April, 1838, must be regarded as the first complete geological map of Ireland that was regularly published. Ihave not been able to ascertain whether any of Griffith’s earlier manuscript maps are in existence. In August, 1838, the large geological map of Ireland appears to have been exhibited at the British Association Meeting in Newcastle; but it was not regularly published till March, 1859. A second edition of the map was published in 1855 by order of the Treasury. The Wollaston Medal, which was in 1831 awarded to William Smith for his Geological Map of England and Wales, was in 1854 presented to Sir Richard Griffith for his Geological Map of Ireland. ‘The three pioneer Geological Maps of England, Scotland, and Ireland have now been placed in juxtaposition in the geological gallery of the Science Division of the South Kensington Museum, where they are open to examination and comparison with the earliest geological maps published in France and other countries. A study of these maps will serve to demonstrate the priority claimed, and justly claimed, by Fitton, for the esol maps of this country over those of any other. part of Europe. The Geological Map of the Basin of Paris ths Cuvier and Brongniart was published in 1810, while William Smith’s early maps had appeared in 1799 and 1801; and the maps of England, Scotland, and Ireland, by Smith, Macculloch, and Griffith respectively, were published in 1815, 1835, and 1888, the first complete Geological Map of France, that of Elie de Beaumont and Dufrenoy, making its appearance in 1840. IJ.—A Coturction or Eayrrian Fosstt EcHInoIpea. By J. W. Grecory, D.Sc., F.G.S. (PLATES V AND VI.) \HE first collection of Egyptian fossils sent for determination by Captain Lyons, R.E., Director of the Egyptian Geological Survey, to the British Museum, includes an interesting series ae Echinoidea, which has been intrusted to me for examination. It is hardly necessary to state that our knowledge of the fossil echinid faunas of Egypt is mainly due to M. P. de Denis Te Ba who has described a large series in two admirable BRELOG 2 S88" 1 P. de Loriol, ‘‘ Monographie des Behinides contenus dans les couches nummu- litiques de Egypte” : Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii (1881), pp- 59-148, 11 pls. ‘‘ Kocaene Echinoideen aus Aegypten und der libyschen Wiiste”: Beitr. Geol. Pal. libysch. Wuiste, Abth. ii, Ht. 1, Palzontogr. Suppl., 1883, pp. 1-49, 11 pls. 150 ID lls Ve Gregory — Egyptian Echinoidea. The echinids in the Egyptian Geological Survey Collection include 79 specimens, which are referred to 15 genera and to 30 species, of which three are new. The horizons are known in each case, but the localities are not stated for one set, which apparently belong to an old collection preserved in the Cairo Museum. The horizons represented are as follows :— Pleistocene. Middle Miocene—Helvetian Series: Siuah. Upper Eocene—Bartonian Series. Middle Kocene—Mokattam Series. Lower EHocene—Libyan Series. Cretaceous—Turonian. Genus RHABDOCIDARIS, Desor, 1856. 1. Reaspociparis LIBYENs!s, n.sp. DIAGNosis. Test large and depressed; width much greater than the height. The shape is decagonal, with the sides all concave. The ambulacral areas occupy deep depressions, while the central suture of the inter- ambulacral areas is also depressed. Interambulacra.—Each vertical series consists of nine or ten plates. The tubercles are very prominent, the bases are perforated, and the mamelons strongly crenulate. The scrobicular areas are not con- fluent, but separated by one or two lines of granules. The scrobicular circles are well developed, the granules being much larger than those covering the rest of the plates. The tubercles are separated from the ambulacral suture by a series of small crowded granules, of which there are four or five rows at the ambitus. The granulated area between the tubercles and the median interambulacral suture is about twice as wide as on the other side; it is ornamented at the ambitus by six or seven rows of granules. Ambulacral plates.—About eleven correspond to an ambital inter- ambulacral plate. The pores of each pair are very wide apart, but are connected by a well-developed groove. The granular area down the middle of the ambulacrum is wide, and consists of two large and one or two small granules on each ambulacral plate. Apical area large, pentagonal. Dimensions. mm. Height of test beh Pes ae ade a xe 30 Diameter of test —... 300 300 500 356 305 54 Diameter of apical system ... Ae 060 300 300 18 Ambulacrum: width of poriferous zone at ambitus ase 2 width of interporiferous zone at ambitus ... 4 Interambulacrum : height of ambital plate 000 B09 7 width of ambital plate 13 width of median granulated area ‘of interambulacrum at ambitus ... 4 Distripution.— Lower Eocene — Libyan Series: near Assiut; Coll. Geol. Surv. Egypt, No. 629. Dr. J. W. Gregory—Egyptian Echinoidea. 151 Ficures. — Pl. V, Fig. la, test from the side; 6, from above. Fig. lc, two ambital interambulacral plates, x 2 diam. Fig. 1d, two ambital ambulacral plates, x 4 diam. AFFINITIES.—This echinid is most nearly allied to Rhabdocidaris itala (Laube),' which has been described from the Egyptian Hocene by M. de Loriol-le-Fort. The principal difference between them is that in #&. itala the tubercles are non-crenulate, whereas in Rh. Libyensis they are strongly crenulate. The tubercles are also taller. The shape of the test is more like that of R. Zitteli, Lor.,’ but in that species the granulated areas of the interambulacra are much more restricted. : The third echinid with which it must be compared is Porocidaris Schmideli (Minst.),° with which it agrees in the crenulation of the tubercles. But the new species has not the slits around the bases of the mamelons; the interambulacral plates are much taller; in a British Museum specimen (No. 75,669) of P. Schmideli the height of the ambital plates is to the width as 9:13; and in P. Schmideli the epistroma consists of coarser and more uniform granules. Genus PSPAMMEOCHINUS, L. Agassiz, 1846. 1. Psammecuinus Dvuctet, Wright, 1855. Synonymy.—See Gregory, “ Maltese Echinoidea”: Trans. Roy. Soc. Edinb., vol. xxxvi (1891), p. 590. Disrrisution.—Up. Miocene—Tortonian: Malta. Mid. Miocene— Helvetian: Egypt; Coll. Geol. Surv. Egypt, No. 822. There is a broken specimen of a Psammechinus in the collection which agrees in the characters shown with this well-known Maltese species. The granulation of an ambital plate of the Hgyptian specimen is shown on Pl. V, Fig. 3. The species has not pre- viously been recorded from Hgypt. An allied African species is P. Soubellensis, Per & Gauth.,* in which, however, one tubercle on each interambulacral plate is much larger than the rest of the horizontal series. 2. PsamMecuinus Lyonst, n.sp. DraGnosts. Test small; somewhat conical above, with tumid, well-rounded sides. Base flat. Seen from above the shape is sub-pentagonal, but with well-rounded angles. Ambulacra.—Kach ambulacral series consists of about thirteen plates, each of which bears a single conspicuous tubercle. The pore pairs are arranged in well-curved triplets. ~ A double series of miliary granules runs down the middle of each area. The scrobicular areas of adjacent plates in the same vertical series are confluent. 1 Cidaris itala, G. C. Laube, ‘‘ Ech. vicent. Tert. Geb.’’: Denk. Ak. Wiss. Wien, vol. xxix, pt. 2 (1869), p. 9, pl. i, fig. 3. 2 De Loriol, 1883, Beitr. libysch. Wiiste, vol. ii, pt. 1, p. 8, pl. i, figs. 1, 11. 3 Oidarites Schmidelii, Minster, in Goldtuss, Petret. Germ., vol.i, p. 120, pl. xl, fig. 4. De Loriol, 1883, op. cit., p. 9, pl. i, fig. 10. F 2 pan & Gauthier, Ech. toss. Algér., vol. iii, fase. 10 (1891), p. 252, pl. v, gs. 1-4. 152 Dio Ve Gregory—Egyptian Echinoidea. Tnterambulacra of about ten plates in each vertical series. Hach plate bears a prominent tubercle. The miliary granules are abundant and well developed. The scrobicular circles are complete, those on the upper border of one plate completing the circle of the plate above. Peristome very large; branchial slits deep. DIMENSIONS. mm. Height of test Ar B58 x8 Ase cae oes 5:5 Diameter Olbestimemese See BG ae 9:5 Width of ambulacrum at ambitus .. ioe ne aes 30 Width of interambulacrum at ambitus ee eas ase D3 Diameter of peristome S06 : tee 4-5 Distripution.— Mid. Misono Sree Gdet Cpe Coll. Geol. Surv. Egypt, Nos. 977, 988. Fieurns.—Pl. V, Figs. 4a and 6, a test from the side and from below, x 2 diam. Fig. 4c, ambital plates, x 8 diam. Fig. 5, ambital plates of another specimen, x 8 diam. Arrinitizs.—The species, by its unituberculate, multigranulate interambulacral plates, belongs to the series of species which Pomel grouped as the genus Arbacina; while by the deep, narrow branchial slits it is allied to the same author’s Oligophyma. Its nearest ally is Psammechinus subrugosus, Pomel, from the Pliocene of Oran, in which the mamelon of the primary tubercles is much larger, there are some secondary interambulaeral tubercles, and the ambital interambulacral plates are longer. Psammechinus levior, Pomel,” from the same deposits, has a more scanty epistroma. The specimen illustrated by Pl. V, Fig. 5, resembles the Arbacina asperata, Pomel,® from the Pliocene of Gren! but in that form the tubercles have a much larger, flat mamelon, which is about two-thirds instead of one-third the diameter of the boss. It also resembles a small Persian Miocene Psammechinus affinis, Fuchs,* in which the scrobicular circles are complete on each plate, so that the adjacent scrobicular areas are separated by two lines of granules instead of by only one. Oligophyma cellensis, Pomel,® is another ally, but that has a much smaller peristome and longer, lower interambulacral plates. Genus COPTOSOMA, Desor, 1858. 1. Coprosoma Tuevestenss, Per. & G. Cyphosoma Thevestense, Peron & Gauthier, 1879: ‘‘ Ech. foss. Algér.,” fasc. vi, p. 105, pl. xiii, figs. 5-8. DistrisuTion.—Turonian: Tebessa, near Constantine, Algeria. — Turonian (?) : Abu Roasch, Egypt; Coll. Geol. Surv. Egypt, No. 50. * Pomel, ‘‘ Pal. Algér.,’’ Zooph., fase. 2, Ech., livr. 1 (1885), pl. C, xii, figs. 1-4. lipids Dl. C, xii, figs. 5-8. ‘' SP libide pls Ce xa, fies. 5-8. 2 Fuchs, “Tert. Ech. Persien’”?: Sitz. Ak. Wiss. Wien, vol. Ixxxi, pt. 1 (1880), p- 99, pl., figs. 6-16. S o Rommel opscits, ploC. axe micsemle=ge Dr. J. W. Gregory—Egyptian Echinoidea. 158 Remarxs.—This species is represented by three specimens. The pores are in ares of five to six pairs in each compound ambulacral plate. The specimens agree with the Algerian type in all important respects. The ambulacral plates are unituberculate, and each tubercle is surrounded by a complete scrobicular circle, so that the scrobicular areas are not confluent. The tuberculation of an Kgyptian specimen is shown on Pl. V, Fig. 2. Genus LAGANUM, Gray, 1825. 1. Lacanum pEpREssvuM, Less. Synonymy.—See A. Agassiz, “ Revision of Hchini,” pt. i, 1872, p- 1388. DisrrisutTion. — Recent: Pacific and Indian Oceans, Red Sea, Persian Gulf. Pleistocene: HE. Africa; Suez; Coll. Geol. Surv. Egypt, No. 968. Remarks.—The collection includes six specimens of a Laganum from the Pleistocene of the Suez Canal (Coll. Geol. Surv. Egypt, No. 968). The specimens appear at first sight to differ from the typical L. depressum, as the margins are tumid, and there is a depression around the test between the apex and the margin. This character is described by Professor A. Agassiz in L. Bonani,! whereas the test of L. depressum is said® to have thin margins. ‘The shape of the petals in one or two specimens is also different from the typical L. depressum, as the petals are more pointed at their outer ends. Hxamination, however, of the large series of L. de- pressum in the Zoological Department shows that these characters vary so much in this species that the Egyptian fossils may be safely referred to it. Some specimens registered as 58. 5. 15. 154, have equally pointed petals; others from the Kingsmill Islands have the petals pointed at the ends, but the poriferous zones are broader ; while in some other specimens the pore-zones are as narrow as in the fossil specimens from Suez. Among the many varieties of L. depressum these specimens are most nearly allied to Laganum attenuatum, L. Ag.,> with which they agree in the circular actinal depression and the general shape of the test. Some of the six specimens have the external shape of the variety L. ellipticum, L. Ag.,* and others have the more strongly pentagonal shape of the typical L. depressum.° L. attenuatum is a variety most typical of the Red Sea and Persian Gulf. Genus SCUTELLA, Lam., 1816. 1. ScurELLA suBROTUNDA var. Pauuensis, L. Ag.,° 1841. Remarxs.—This echinid is represented in the collection by two Miocene specimens (No. 995), of which one is broken. ‘The 1 A. Agassiz, Revision Echini, pt. ili (1873), p. 517. 2 Tbid., p. 518. 3 L. Agassiz and Desor, ‘‘ Cat. Raiss.’’: Ann. Sci. nat., vol. vii (1847), p. 132. 4 L. Agassiz, Mon. Scut., p. 111, pl. xxiii, figs. 13, 14. ® Cf. ibid., pl. xxiii, figs. 1-3. § Scutella Paulensis, L. Agassiz, Monogr. Scutelles, 1841, p. 83, pl. xix, figs. 8-10. 154 Dr. J. W. Gregory—Egyptian Echinoidea. echinids agree with S. subrotunda (non Leske) in the length of the petals, whereby they differ from the Tongrian S. striatula, Mare. de Serr. They differ from the typical S. subrotunda, Leske, by the absence of the notch in the posterior margin of the test behind the anus. In this character they agree with S. Paulensis, L. Ag.; but they differ from L. Agassiz’s type of that form by their greater equality of length and breadth. Agassiz remarked the close resemblance of S. Paulensis and S. subrotunda ; and it seems to me, as the shape is inconstant, that the former species should be reduced to a variety of the latter, characterized by the absence of the notch and by the less branched actinal furrows. The branching of the furrows is, however, inconstant; they are not well marked in the specimens; but in some areas the furrows branch once as in S. Paulensis, whereas in other areas there are distinct secondary branches as well. The original locality of S. Paulensis is St. Paul-trois-Chateaux, near Dax, and its horizon is Lower Miocene or Langhian.’ Fuchs has described two Egyptian Miocene Scutelle. In S. rostrata, Fuchs,” from Siuah, the posterior margin is curved and not truncate; and the interporiferous areas of the petals is broader than in the two echinids of the Egyptian Survey collection. The general shape of these specimens agrees with that of S. ammonis, Fuchs,’ in which the petals are a little shorter; thus, the length of the anterior petal is 38; of the distance from the inner end of the petal to the anterior margin of the test, whereas the same proportion in these specimens is 2. Genus CONOCLYPEUS, L. Agassiz, 1839. 1. ConoctyrEus Denanovet, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 82, pl. ii, fig. 17. Var. MILVIFORMIS,‘ nov. Distrieurion. — Libyan Series: Coll. Geol. Surv. Egypt, ex No. 858. Pl. VI, Fig. 2; two-thirds natural size. RemaRr&s.—Five specimens in the collection agree in all essential respects with De Loriol-le-Fort’s C. Delanouei, except that the shape is not elliptical but somewhat kite-shaped. The greatest width is a trifle anterior to the peristome; the sides thence run straight backward, converging slightly till opposite the anterior margin of the periproct ; thence they bend sharply round to the well-curved posterior extremity. As De Loriol’s figure (17a) is not regularly elliptical, and as the test shows a tendency towards this kite-shaped base, it seems unnecessary to make a new species for these echinids. But the difference is so constant in the five specimens that it is desirable to notice it as a varietal character. * e.g. Depéret, ‘‘ Classification et parallelisme du Systéme Miocéne’’: Bull. Soc. géol. France, ser. 3, vol. xxi (1893), p. 176. ; * Fuchs, Beitr. libysch. Wiiste, vol. i (1883), p. 48, pl. xvii, figs. 4-6. ® Fuchs, ibid., p. 48, pl. xiv, figs. 1-4. * From mzlvus, ‘a kite,’ the test being kite-shaped. Dr. J. W. Gregory—Egyptian Echinoidea. 155 Genus RHYNCHOPYGUS, D’Orbigny, 1855. 1. Rayncnoryeus Zrrruni, De Loriol, 1883. “Beitr. libysch. Wiiste,” vol. ii, pt. 1, p. 18, pl. ii, figs. 9-11. Distripution. — Mokattam Series: Minieh (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, ex Nos. 862, 863. RemarKs.—The echinid referred to this species differs from the type only by being slightly broader in proportion to its width. Genus HCHINOLAMPAS, Gray, 1825. 1. EcHINOLAMPAS TUMIDOPETALUM, n.Sp. Dracnosts. Test large and tall, subconical, rising Fae a level base. Seen from above the shape is sub-elliptical, but the posterior half is broader and fuller than the anterior part. Apical area and mouth subcentral. Ambulacra.—The petaloid portions are very swollen and upraised. The inequality in the length of the poriferous zones of the antero- lateral pair of petals is considerable. The petals are long, reaching nearly to the margins. The poriferous zones are narrow ; the inter- poriferous area is long, lanceolate. Floscelle well developed; the bourrelets large and conspicuous. Dimenstons. Crushed specimen. mm. mm. Height BE ae boc 660 600 48 ahs 49 Length ae ie a0 on 600 78 ae 79 Breadth 600 65 ates 56 Length of petal of antero-lateral ambulacrum 38 sds 35 Width of petal of antero-lateral ambulacrum 11 360 10°5 Width of poriferous zone of ditto... 260 2 ae 2 Width of interporiferous zone of ditto 500 7 Se 6°5 Distance of apex from anterior margin... 38 a 30 Distance of mouth from anterior margin ... 35 Distripurion.—Miocene : Coll. Geol. Surv. Egypt, Nos. 966, 972. Ficurrs.—Pl. VI, Fig. la, a specimen from above; Fig. 1b, the same specimen from the side: nat. size. AFFINITIES.—This species is represented in the collection by four specimens, of which three are somewhat broken, while the fourth is a little deformed by lateral pressure. The most striking character of the species is its swollen ambulacra, which are of the type met with in Achinolampas stellifera, from the Calcaire Grossier. From this species H. tumidopetalum differs by its greater size and more conical test. Among known species of Zchinolampas this most nearly resembles EH. Anguille, Cott.,: trom which it differs by the tumid petals and by the more conical form of the test. The outline seen from above or below is almost identical with Cotteau’s figures 7 and 8 of his West Indian species. chinolampas florescens, Pom., var. coarctata,’ 1 G. Cotteau, ‘‘Descr. Ech. tert. St. Barth. et Anguilla’’: Handl. k. Svens. Vet. Akad., vol. xiii, No. 9 (1875), p. 24, pl. iv, figs. 4- 8. 2 A. Pomel, ‘‘ Ech. Kef. Ighoud”’ : Mat. Carte ‘géol. Algérie, ser.i, Pal. (1885), p- 26, pl. iii, figs. 12-14. 156 Dr. J. W. Gregory—Egyptian Echinoidea. has a high test of much the same form as E. twmidopetalum; but the petals are much broader, shorter, and more leaf-like, and the floscelle less conspicuous. 2, EcHINOLAMPAS GLOBULUS, Laube, 1869. « Bch. vicent. Tert. Geb. ’?: Denk. Ak. Wiss. Wien, vol. xxix, pt. 2 (1869), p. 24, pl. iv, fig. 5. Distripution. — Lower Eocene—Libyan Series: near Assiut, Egypt (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, No 6381. ‘'en specimens of this variable species from the Lower Hocene near Assiut. 8. EcuINOLAMPAS AMYGDALA, Desor, 1847. Agassiz & Desor, “Cat. Raiss.”: Ann. Sci. nat., Zool., ser. 3, vol. vii, p. 164. There is one echinid in the collection (ew Nos. 862-38) the pro- portions of which agree with those of the Egyptian specimen, which, according to De Loriol, is the typical form of this species. The species was based by Desor on an Egyptian fossil. The dimensions are as follow :— Coll. Geol. Surv. Egypt. De Loriol-le- Fort. Length ace So Lp 42 mm. eee 30-38 mm. Breadth 206 ues ae 20 mm. oy — Ratio of breadth to length ... “48 sat “00 Height ma hs uae 32 mm. ane = Ratio of height to length .... “76 ; ofa Disrripution.—Mokattam Series: Mokattam (De Loriol-le-Fort). Libyan Series : Coll. Geol. Surv. Egypt, ex Nos. 862-3. 4. Ecutnonampas Prrrireri, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 95, pl. v, fig. 2. Distripution.—Mokattam Series: Mokattam, Thebes (De Loriol- le-Fort) ; Coll. Geol. Surv. Egypt, ex No. 899. The collection includes a small specimen from the Mokattam Series, which appears to be referable to #. Perrieri, Lor., though that species was described from the Upper Hocene beds of the Siuah Oasis. M. de Loriol-le-Fort did, however, record a doubtful speci- men from the Mokattam beds of the Beharieh Oasis. The dimensions are as follow :— De Loriol. Egypt. Geol. Surv., ex No. 859. Length eae ae pas 62-62 mm. ... 46 mm. Breadth ae a cee = 600 ... 3838 mm. Ratio of breadth to length ... 82) ecw. ae 83 Height des Aap 603 == cto ... 20°5 mm. Ratio of height to length ... 42-45... 300 “44 o. Ecninonampas Lisycus, De Loriol, 1883. “ Beitr. libysch. Wiiste,” vol. ii, pt. 1, p. 31, pl. v, figs. 1-3. Disrrisurion.—Mokattam Series: Siuah (De Loriol-le- Fort); — Coll. Geol. Surv. Egypt, one specimen ex No. 859. No. 859 in the Egyptian Survey Collection includes two specimens which are clearly specifically distinct. The larger specimen has the Dr. J. W. Gregory—Egyptian Echinoidea. 157 following dimensions, which are those of H. Libycus and £. sub- cylindricus, Des. But the characters of the petals show that the Hgyptian Survey specimen is nearer to the former. The specimen is broken at the posterior end, so the specific determination is somewhat uncertain. DIMENSIONS. Length ats Abe ate ee Bi Sala see 70 mm. Breadth Bee 5c A a A Ad 55 mm. Ratio of breadth to length bel ise sige nae es “786 Height yee 900 vs 506 we 35 mm. Ratio of height to length aul ot ae aa a “50 6. EcHINOLAMPAS AMPLUS, mache 1883. “Beitr. Kenntn. Miocaenfauna Aegypt.”: Beitr. Geol. Pal. Lib. Wiiste, vol. i, p. 45, pl. xiv, figs. 5-8. Distripution. — Miocene: Siuah and Geneffe (Fuchs) ; Coll. Geol. Surv. Egypt, No. 643; near Wady Jiaffra, between Cairo and Suez, Camp No. 9. Genus HUPATAGUS, L. Agassiz, 1847. 1. Evuparagus Corrraur, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 139, pl. xi, figs. 8-10. Disrrrsution.— Libyan Series: near Thebes (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, ex Nos. 861 and 867. 2. Evpatacus Lisycus, De Loriol, 1883. “ Beitr. libysch. Wiiste,” vol. ii, pt. 1, p. 52, pl. xi, fig. 4. Distrigution. — Libyan Series: El Guss Abu Said, west of Farafrah (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, three specimens ex No. 868. Genus HYPSOPATAGUS, Pomel, 1885. 1. ? Hyresoparacus LureBvret (De Loriol), 1881. Macropneustes Lefebvrei, De Loriol, 1881: Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 181, pl. ix, figs. 7-9. Hypsospatangus Lefebvrei, Cotteau, 1886: Pal. frang. Terr. tert., vol. i, Hoe. Hch., p- 96. Distripution.— Libyan Series: near Assiut, Minieh, and El Guss Abu Said, west of Farafrah (De Loriol-le-Fort) ; ? Assiut ; Coll. Geol. Surv. Egypt, ew No. 631. The only specimen that may belong to this species is one that is so much broken at the hinder end that it is not possible to’ determine whether a fasciole was present. The shape of the petals is, however, nearer to that of Hypsopatugus than to Hupatagus. 2. HypsopaTaGus, sp. Libyan Series: Coll. Geol. Surv. Egypt, ex Nos. 862-8, 867. There are two echinids in the collection which are elongate forms of Hypsopatagus, but they are too ill-preserved for description. The outline of one is shown on Pl. VI, Fig. 4, which presents 158 Dr. J. W. Gregory—Egyptian Echinoidea. a considerable resemblance to the Hupatagus Siokutensis, Fuchs,} which has, however, a more cordate or elliptical test. Genus HEMIASTER, Desor, 1847. 1. Hemraster ScuweinFurtHt, De Loriol, 1883. “ Beitr. libysch. Wiiste,” vol. 11, pt. 1, p. 34, pl. viii, figs. 83-5 Distripution. — Libyan Series: El Guss Abu Said, west ‘of Farafrah (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, ex Nos. 862-3. PERICOSMUS, L. Ag., 1847. 1. Pericosmus tatus, Ag. & Des., 1847. Agassiz & Desor., op. cit., p. 19, pl. vi, figs. xvi, 1. Remarks.—This well-known echinid is represented in the col- lection by two specimens from the Miocene (Geol. Surv. Coll. Egypt, No. 964). They agree with Agassiz’s cast (M 28), but differ slightly from Agassiz & Desor’s figure by the fact that posteriorly the test slightly overhangs the periproct, which cannot be seen from above. The specimens agree with Cotteau’s admirable description of the species ;* and the posterior extremity of the test agrees with his figure of P. Orbignyi, Cott., to which he applies the same description as to P. latus. Hence the Egyptian form agrees with Cotteau’s description better than with the original figure. The echinids differ from P. Orbigqnyi, Cott., by the greater equality of length and breadth, the dimensions being 75 mm. and 76 mm. respectively. 2. Pertcosmus Prront, Cott. G. Cotteau, ‘‘Faune terr. tert. Corse”: Ann. Soc. Agric. Lyons, ser: 4, vol. ix, 1877, p: 314, pl. xiv, figs. 3,4. DistrigutTion. — Helvetian: Corsica; Egypt; Coll. Geol. Surv. Egypt, No. 659. The collection contains three broken Pericosmi, which have the anterior apex, steep anterior slope, and long posterior slope characteristic of P. Peroni, Cott. Two of the three echinids are too broken for satisfactory determination, but a third shows the form of P. Peroni fairly well. Genus LINTHIA, Merian, 1858. 1. Linrata Ascuersont, De Loriol, 1883. “ Beitr. libysch. Wiste,” vol. ii, pt. 1, p. 37, pl. ix, figs. 1-4. Disrrreurion.—Libyan Series: Gebel Ter, near Esneh, and west of Farafrah (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, ex Nos. 862-3. 2. Linrata HsnrHensis—ASCHERSONI. Linthia Esnehensis, De Loriol, 1883 : “ Beitr. libysch. Wiiste,” vol. ii, pt. Lp: 39) ppl ix, digs. o,/0: L. Aschersoni, De Loriol, 1883: ibid., p. 87, pl. ix, figs. 1-4. 1 Fuchs, ‘‘ Tert. Kch. Persien’’: Sitz. Ak. Wiss. Wien, vol. lxxxi, pt. 1 (1880), p- 100, pl., figs. 17-20. > G. Cotteau, ‘‘ Faune terr. tert. Corse’’?: Ann. Soc. Agric. Lyons, ser. 4, vol. ix, pp- 310-12. Dr. J. W. Gregory—Egyptian Echinoidea. 159 There is in the collection a specimen which is intermediate between the above, but nearer, if anything, to L. Hsnehensis. The relative dimensions are as follows :— Esnehensis. -Aschersoni. Egypt. Sury. Coll. Length ... .. 80-42 mm. 26-37 mm. 36 mm. Ratio of breadth to leneth 1-110 ... I see anaaluele4 Ratio of height to length PUB) ooo 8) = OY a0 “74 But the Egyptian Survey specimen has the shallow anteal notch and broader anterior ambulacrum of L. Aschersoni; the ridge of the posterior interradius is higher than in L. Aschersoni, but lower than in L. Hsnehensis. ‘The apical disc of this echinid is shown on PI. VI, Fig. 3. Distripution.— L. Bixoctaenst, Lor., Libyan at Gebel Ter, near Hsneh (De Loriol-le-Fort). L. Aselvansant, Lor., Libyan at Gebel Ter, near Esneh, and west of Farafrah. The above-mentioned Egyptian fossil is from the Libyan Series (De Loriol-le-Fort), ex Nos. 864-5. 3. LINTHIA CAVERNOSA, De Loriol, 1881. _ Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 111, pl. viii, fies. 8-10. Disrrisution.— Libyan Series: Gebel Omm-el-Renneiem; Hl Aouhi, near Edfou ; Djebel Fatira (De Loriol-le-Fort) ; Coll. Geol. Surv. Heypt, ex No. 867. 4. Linrata Denanovst, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 109, pl. vii, fig. 12. Distrrpution.—Mokattam Series: Mokattam (De Loriol-le-Fort). Libyan Series: Gebel Ter, near Hsneh (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, ex No. 996. The collection includes one large, well-preserved specimen of this species. Its dimensions are: mm. Length 600 06 300 00 bas bce boc 60 Breadth du 366 bag ae eA as 000 575 Height 500 se sus 45 Distance of apical system from anterior margin se 609 20 5. Lryrura (?) Correaur, Tournouer, 1870. SyNoNyYMyY. Periaster Cotteaut, Tournouer, 1870, “ Ech. calc. & aster. sud-ouest France”: Actes Soc. linn. Bord., vol. xxvii, p. 33, Dleexvilh foe: Linthia Cotteaui, Cotteau, 1886: “Pal. frang. Terr. tert.,” vol. i, Gib, Oe Aésll5 (oll, Woot Distrisution.—Mid. Hocene: Hastingues, Landes (Tournouer & Cotteau). Libyan Series: Egypt; Coll. Geol. Surv. Egypt, ex No. 868. Remarks.—The generic position of this species seems to me doubtful. The dimensions of the specimen assigned to it are as follow :— 160 DrNIW: Gregory—Egyptian Echinoidea. Length eae écc 235 bon boo ei ase 37 mm. Breadth 500 300 956 ode 680 35 mm. Ratio of breadth to length bod ie sh a ue “95 Height one soc oo 200 300 27°5 mm. Ratio of height to length ae 3c 306 o00 ies Apical disc : * distance from anterior margin 17 mm. Apical dise : ratio of distance from anterior margin to length “46 The specimen shows hoth peripetalous and lateral fascioles. The dimensions show that the apical disc is anterior in position, and hence the fossil is a Linthia. The echinid has, however, the very short posterior ambulacral petals, while the petals of the anterior pair are longer and more flexuous. The petals, moreover, are deep. These characters are unusual in Linthia, but are very frequent in Schizaster. Hence the species has more the characters of a Schizaster with an anterior apical disc than of a normal Linthia. Cotteau, indeed, remarks (op. cit., p. 243) that the French specimens have the apical disc either central or even slightly posterior ; so that he was doubtful as to the generic position of the species. The nearest allied echinid previously recorded from Hgypt is the Linthia Arizensis (D’Arch.), which is, however, much flatter and more depressed. As there is only one specimen of this form, its specific determination is necessarily somewhat uncertain. Genus SCHIZASTER, L. Agassiz, 1847. 1. Scuizaster Tuesensts, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 125, pl. ix, figs. 5-6. Disrrisution. — Libyan Series: Todtenberg, near Assiut (De Loriol-le-Fort) ; Coll. Geol. Surv. Egypt, ex No. 868. 2. ScuizaAsteR Moxarramensis, De Loriol, 1883. “ Beitr. libysch. Wiiste,” vol. ii, pt. 1, p. 41, pl. x, figs. 1, 2. Distrisution. —- Mokattam Series: Mokattam (De Loriol-le- Fort). Libyan Series: Gebel Ter, near Hsneh (De Loriol-le-Fort) ; Geol. Surv. Egypt, ex No. 867. 3. SCHIZASTER ZitTei, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 122, pl. ix, fig. 2. There are one good and three crushed specimens of this species in Nos. 864-5. Disrrisution.—Mokattam Series: Mokattam (De Loriol-le-Fort). Libyan Series: Coll. Geol. Surv. Egypt, ex Nos. 864-5 ; Gebel Ter, near Hsneh (De Loriol-le- Fort). 4, Scuizaster Gavpryi, De Loriol, 1881. Mém. Soc. Phys. Hist. nat. Genéve, vol. xxvii, p. 120, pl. ix, fig. 1. DistriputTion.—Mokattam Series: near Thebes; Mokattam (De — Loriol-le-Fort). Libyan Series: Coll. Geol. Surv. Egypt, No. 996. The collection includes two specimens of this species. The two specimens differ in the size of the anterior ambulacral depression ; A. J. Jukes-Browne—The Vale of Marshwood. 161 in one of them the ambulacral furrow is considerably larger than in the other. It seems unnecessary to regard this as a specific or varietal difference, for it may be either sexual or a seasonal variation, the anterior furrow being enlarged to serve as a marsupium. EXPLANATION OF PLATE V. Fies. la and 16. Rhabdocidaris Libyensis, nov. sp., from the side and from above ; nat. size. Fig. le, ambital interambulacral plates of the same, x 2 diam. Fig. 1d, ambital ambulacral plates of the same, x 4 diam. Fig. 2. Coptosoma Thevestense, Per. & G., ambital plates, x 4 diam. Turonian: Abu Roasch. Fic. 3. Psammechinus Duciez, Wright, ambital plates ef Egyptian specimen, x 5 diam. Fies. 4 and 5. Psammechinus Lyonsi, nov. sp. Fig. 4a, side view, x 2 diam. ; Fig. 46, actinal view, x 2 diam.; Fig. 4c, ambital plates, x 8diam. Fie. 5. Ambital interambulacral plates of another specimen, x 8 diam. EXPLANATION OF PLATE VI. Fies. la and 16. Echinolampas tumidopetalwm, nov. sp., abactinal and lateral views ; nat. size. Fie. 2. Conoclypeus Delanouei, Lor., var. milviformis, nov., actinal surface; two- thirds nat. size. Fie. 3. Linthia Esnehensis —Aschersoni, apical disc, x 5 diam. Fic. 4. Hypsopatagus, sp., side view; nat. size. IJ].—Tue Oricgin or tHe VALE or Marsnwoop 1n West Dorset.! By A. J. Juxrs-Brownz, B.A., F.G.S. T\HE great sheet of Chalk which, with the subjacent Greensand and Gault, stretches through so large a part of Southern England and underlies the whole of the Hampshire Basin, termi- nates abruptly in West Dorset. There is no doubt that the Upper Cretaceous rocks once spread continuously over the Jurassic hills east of Bridport and across the Vale of Marshwood, and were united to the corresponding beds in East Devon, where the Chalk and Greensand are so conspicuous in the cliffs near Beer Head. To those who are unacquainted with geological methods this statement may seem highly imaginative, since, at the present time, there is a broad intervening tract, from the centre of which all traces of Cretaceous strata have been removed, and around which only a few isolated patches or outliers of Greensand remain as relics of their former extension; yet to the eye of a geologist these very outliers, of which Pilsdon Pen is one, are clear and certain proofs that a continuous sheet of the same material once overspread the whole area. The physical features of this area may be briefly described, as they are not likely to be familiar to those who do not live in the west of Dorset. The Vale of Marshwood is an area of low ground, most of which lies between 100 and 200 feet above the sea; its length is about five miles and its breadth three; its floor consists of the clays of the Lower and Middle Lias, and it is encircled by steep 1 This paper is reprinted, with some alterations, from the Proceedings of the Dorset Nat. Hist. and Ant. Field Club, vol. xviii, and is published with the permission of the Director-General of the Geological Survey of Great Britain. DECADE IV.—VOL. V.—NO. IV. 11 162 A. J. Jukes-Browne—The Vale of Marshwood. slopes formed by the yellow micaceous sands of the Marlstone Beds, the cincture of the hills being only broken on the south by the gaps through which the rivers Char and Simene escape to the sea and by a dry gap or pass above Chideock. The hills on the north side of the Vale are higher than those on the south side, and they form the watershed dividing the valley of the Axe from the valley of the Char, which occupies the greater part of Marshwood Vale. Pilsdon Pen and Lewesdon Hill are the highest hills in Dorset, Pilsdon being 907 feet and Lewesdon 894 feet, according to the latest Ordnance Survey Map. It is only on the Blackdown Hills in Devon that the Upper Greensand reaches a greater height than this, and these hills, although so much farther west, do not attain to more than 930 feet. It is obvious, therefore, that there must be some local reason for the great height to which the Greensand reaches in Dorset, and yet I am not aware that any geologist has accounted for the fact. It may seem a paradox to say that the height of the Greensand hills and great hollow of the Vale of Marshwood are due to one and the same cause, yet it is true that they are so closely related to one another that the history of the one involves the history of the other. This history begins with the uplift of the strata which took place in Miocene or Pliocene times, and bent the beds into © a dome-shaped elevation, or pericline, i.e., an area in which the strata are bent up so as to dip outwards in all directions from a central spot or axis. I propose to ascertain the probable whereabouts of this centre by a consideration of the levels through which the base of the Upper Greensand passes in Hast Devon and West Dorset. It might be thought that this spot could be found more easily by examining the arrangement of the Jurassic rocks on the borders of the Vale of Marshwood, but though these undoubtedly show the existence of an anticlinal axis running in an east-and-west direction from which the strata slope to north and south, the curve to east and west is not so apparent in them because they had received a decided easterly tilt before the Greensand was deposited on them. Moreover, the Jurassic rocks are broken by many faults, and only a few of these affect the Cretaceous strata, for most of them seem to date from the Purbeck and Wealden periods, when the above- mentioned tilting was produced. It is therefore by the position and relative heights attained by the base-line of the Gault and Greensand that the periclinal uplitt of this district can best be determined, and by transferring the boundary-lines from the published Geological Survey map to the six-inch county maps, we can easily trace the rise and fall of this base-line. The boundary-lines on the old Geological Survey map are not everywhere correct, but I have good reason to believe that this particular boundary is sufficiently accurate for our purpose. _ The map (Fig. 1) is based on the new one-inch Ordnance map, and the geological lines have been partially revised, so that it is more accurate than the old Geological Survey map. Fic. 1.—GzotocetcaAn Map or A Portion or West Dorset. Scale half an inch to a mile. Clays of Mid.and Lower Lias (ig) FOUL gem o iN dy! Kil Sil II Ii) . il : my Fa | yee if ech ui iE | i 8 =f Hy il! | IN =I Pil Nie ith SOLS i 2 {Il x ee eT] ! : i ee WMH | | N sant | i ——on | es Ih i RS | i : iy Chalk =a Upper Greensand ee Lower Ootite “WH Up. Liasand Marlstone Sand mr | ll paws Wee? = en EUMUMAH aa (ey ml ; ee (| (li — Hii im ante Sear. iW" ' 7S ce THD J Ki Be iN ee Sat AN i eee ea | AA lls K—82— fro a eA B= = 164 A. J. Jukes-Browne—The Vale of Marshwood. Commencing with a traverse from west to east through Pilsdon and Lewesdon, and starting the base-line of the Greensand at Secktor, near Axminster, we find it there to be only about 320 feet | above sea-level, and thence it rises gradually eastward till it reaches 580 feet at Birdsmoor Gate, 700 feet at the southern end of Pilsdon, and about 770 feet on Lewesdon. Between Lewesdon and Beaminster there are several faults breaking the Jurassic rocks, but it is not certain that any of them displace the Cretaceous series, and on Hackthorn Hill the base of the Greensand is close to the 500 feet contour. The distance from Lewesdon to this point is four miles, and, assuming the fall to be gradual, it is a little, but not much more, rapid than the rise from the west up to Lewesdon. Taking next a traverse through the southern outliers near the coast, we find the Cretaceous base-line in Black Ven Cliff at about 320 feet above the sea. Thence it rises to about 350 feet in Stone Barrow, and 400 and more on Golden Cap and Langdon Hill, and finally to about 500 feet on Hype Down. Then comes a space of four miles occupied by low ground near Bridport, and when Green- sand is next found on Shipton Hill, its base has fallen to 400 feet, sinking still lower eastward to 300 feet at Askerswell. Along this line of country, then, as along the first, we seem to have a gradual rise and fall in the height of the Cretaceous base-line. We will next trace the rise and fall of the same line from north to south. This is best shown on the western side of the area. North of Thorncombe village the base of the Greensand lies at about 450 feet, on the south side of that outlier in the same latitude it is nearly 500, by Lambert’s Castle it is about 600 feet; thence it falls to 550 feet below Coney’s Castle and to 350 feet at Stonebarrow, 24 miles further south. _ On the eastern side of the district the regularity of the rise is broken. by faults, but we find it rising to a maximum of 600 feet on Drakenorth Hill, east of Poorton, falling thence rapidly both to the north and to the south. Hven where it is faulted up again on Eeggardon Hill it does not seem to get much above 400 feet, and at Combe, near Litton Cheney, it is down to about 500 feet. We may fairly assume that the centre of the uplift, or pericline, will be found by drawing lines between the points where the base- line reaches its greatest height, namely, from Lambert’s Castle to Drakenorth Hill, and from Lewesdon to Eype Down. The inter- section of these lines occurs a little east of Monkswood, above the low ridge which forms the watershed between the Char and the head branch of the Simene brook. We may take this spot as the approximate centre of the pericline, which appears to have an ~ elliptical shape, its longest axis being from east to west and its shortest from north to south. We can even form a good estimate of the height to which the base of the Greensand reached over this — centre by prolonging the actual rise of the base-line in the Pilsdon outlier, for at the north end of Blackdown, by Stony Knap, it is at 500 feet, rising thence to 700 feet below the Pen, and if this rise were continued south-eastward to the spot above mentioned it would A. J. Jukes-Browne—The Vale of Marshwood. 165 bring the base to a height of 877 feet. Assuming the thickness of the Cireemeama there oD have been 180 feet, the Chalk would have come in at about 1,150 feet. The relative levels of sea and land varied, of course, at different epochs of Tertiary time, but we are quite warranted in believing that there was a time when the Chalk and Greensand formed a con- tinuous mantle over the rocks which now occur in West Dorset. Let us next consider how this mantle of Cretaceous material has been so largely removed from the district in question. When the country was raised above the level of the sea at the close of the Oligocene period it must have undergone considerable erosion from he. planing action of the sea waves, and if the flexures were commenced at that time the anticlines would suffer most. We know very little about the history of this part of England during the Miocene and Pliocene times, but the final result of. the successive upheavals and denudations was to leave a surface of erosion which was planed across the flexures, and both upheaval and denudation had been carried on to such an extent that the Chalk had been either entirely or almost entirely removed from the central parts of the anticlinal areas. This surface of erosion was what our American cousins call a peneplain, that is to say, it was not a level plain or plateau, but had its slight irregularities and slopes, and had, moreover, a summit elevation from which it sloped in more than one direction. A con- sideration of the present watersheds and of the river-courses in Dorset and the adjacent counties leads us to infer that the original watershed of this peneplain lay to the north and west of the line now occupied by the Chalk escarpment.! It probably trended from somewhere in the neighbourhood of Wincanton at a high level above Sherborne and Yetminster to Beaminster Down, and thence over Lewesdon and Pilsdon to the hills between Axminster and Lyme. The western part of this line, from Beaminster Down along the ridge on which Lewesdon and Pilsdon stand, is still the watershed between the streams which run southward and those which drain into the rivers Parret and Axe. It will be noticed that this watershed does not coincide with the longer axis of the Marshwood pericline, but lies to the north of it. In order, therefore, to understand the drainage system of this part of Dorset we must imagine a time when the surface of the land sloped gently both northward and southward from the line above- mentioned. On this surface there was a certain accumulation of clay, pebbles, cherts, and flints, the heavy and insoluble relics of the Hocene, Greensand, and Chalk which had been destroyed ; remnants of this deposit, which is generally called “the clay with flints,” still remain on the tops of the higher hills. The rain flowing down the southern slope of this surface gathered into streams, which cut channels for themselves through the Chalk 1 See ‘‘ Origin of the Valleys of North Dorset,”’ in Proc. Dorset N.H. and A.F. Club, vol. xvi, p. 5 166 A. J. Jukes-Browne—The Vale of Marshwood. and Greensand. They ran, of course, high above the present surface, and their courses were prolonged far to the southward before reaching the sea ; indeed, during the Miocene and again in the later Pliocene time it is probable that most of the English Channel was dry Golder: Cap ‘Hardown ill 677 t 1 E ros v2 On :- 2 Pen 850° LLL ZL Pilsdon ildhay Ch aT i RI Fia. 2.—Section across the Vale of Marshwood along the broken line on the Map. Pay aa a tit land, and that these Dorset streams were merely tributaries of a large river which ran westward down the valley of the Channel. Now the slope along which these streams made their way was planed across the summit of the low dome or pericline, which has been described ; and as we have calculated the base of the Green- sand on this summit to have been about 100 feet higher than it is at Lewesdon, where the thickness of Greensand at present is not more than 180 feet, and as the surface sloped southwards from Lewes- don, there cannot have been much Greensand left over the central area of the pericline when the streams began to make their valleys. Hence, as they deepened their channels they would quickly cut through the Greensand on the central area and would soon enter the Jurassic beds on which the sand rests; these beds are the Midford Sand, the Upper Lias clay (which is thin), and the » Marlstone Sands. As soon as any stream cut into the Upper Lias the water on the overlying sands would issue in the form of springs. Thereby the volume of the streams would be increased and at the same time Jandslips would take place, as is always the case where springs issue from sand overlying a clay. The valleys would be rapidly widened, and during periods of upheaval they would be deepened also. Much of this work was probably done during the Glacial Period, and was finally completed during the time when the raised beaches of the South Coast were being elevated to their present height. Over the western part of the pericline the Midford Sands and Upper Lias are absent; that is to say, they were planed off before the Greensand was deposited, and the latter rests directly on the Marlstone Sands. Here the process of valley erosion would continue till the base of these sands was reached, when strong springs would be thrown out by the underlying margaritatus clays, and these clays would be for a certain distance exposed along the valley bottoms. We must remember that all this time the slope of the valley-ways was less than the southerly — inclination of the beds on the southern curve of the pericline; hence the rivers, after cutting A. J. Jukes-Browne—The Vale of Marshiwood. 167 through the lower clays for a space, would again enter the Marlstone Sand and still further south would again enter the Upper Lias and Midford Sand, as shown in the diagram (Fig. 2). Now, where the sides of a valley consist of clay, they are rapidly acted on by rain and frost and are made to recede by frequent landslips, but where they consist of firm and dry sand there is very little slipping and the valleys remain comparatively narrow. ‘Thus it came to pass that a wide tract of clay was gradually exposed over the western part of the periclinal area, while to the southward the rivers pass through valleys with steep slopes on each side, the inter- vening tracts rising into a succession of hills, some of which are capped by patches of Inferior Oolite and others by remnants of the original covering of Greensand. These southern hills are well seen by anyone standing at the foot of Pilsdon Pen, and they look as if they would present an impassable barrier to any river running southward from the watershed on which the observer stands. The rivers which now drain the district are the Char and the Simene, while the Brit drains the eastern part of the periclinal area, and they all make their way through gaps in the southern hills. But, besides the valleys of these rivers, there is a wide gap at the head of the valley of the little river Chid, which runs through Chideock, and I think it probable that this gap was part of the valley of a river which had a more northern source. There is little doubt that in some cases one river-system extended itself at the expense of another, the lateral tributaries of the one encroaching on the area drained by the other, and sometimes entirely cutting off or capturing the headwaters of the adjacent river.’ The present course of the Char is so different from the com- paratively straight courses of the Simene and the Brit, that it suggests the idea of its having absorbed the tributaries of an eastern neighbour. The col at the present head of the Chideock valley does not rise above 250 feet, the hills on each side being double that height, and I am inclined to think that there was a time, before the valleys were carved out to their present depth, when three rivers traversed the Vale of Marshwood, and that the ancestor of the Chid was one of them. The final sculpturing of the country took place during and soon after the close of the Glacial Period, and it was probably then that the capture by the Char of the upper tributaries of the Chid was accomplished. In conclusion, I may briefly call attention to the points of resemblance and difference between the Vale of Marshwood and the Weald of South-Eastern England. Both are elliptical periclinal areas, both have been truncated by planes of (presumably marine) erosion, and both have rivers, which, after traversing the inner plain, pass through gaps in the southern escarpment to reach the sea. In the Weald, however, the watershed coincides roughly with the longer 1 For a case in Lincolnshire described by the author, see Quart. Journ. Geol. Soc., vol. xxxix, p. 596, 1883. 168 A. J. Jukes-Browne—The Vale of Marshwood. axis of the pericline, and the streams run both northward and south- ward, so that both lines of escarpment are trenched by river-valleys. In the case of the Dorsetshire Weald the original watershed was outside and north of the central axis, so that all the streams ran southward and only the southern border is trenched by river-valleys. In both areas, too, the denudation of the central region has laid bare a large tract of clay, and on this clay-soil fine forests of oak- trees came into existence. The great forests of the Weald were famous for their oaks, which in former days contributed largely to the ‘wooden walls of England.” In the western country the Vale of Marshwood was equally celebrated for its oak-trees, and when ships were largely built in the South of England they were much in demand. Many hundreds of fine oak trunks have been taken from the Vale and shipped from Lyme and Bridport. The trade indeed has not entirely ceased, and such cargoes are still embarked at the small port of West Bay, below Bridport; few, however, now come from the Vale of Marshwood, for its woods have disappeared, and the only oaks that remain are hedgerow-trees. With respect to the isolation of Pilsdon and Lewesdon Hills, this has been effected by the excavation of the intervening spaces ; in technical language they are “hills of cireum-denudation.” The interspaces are the heads of the valleys formed by the action of rain and springs on the slopes of the old watershed. The tributaries of | the Axe have trenched it on the north, while on the south side the strong springs thrown out at the base of the Marlstone Sands have eaten backward some little way into the ridge of the original water- shed, causing the actual water-parting to retreat northward. This recession has taken place principally near the villages of Pilsdon and Bettiscombe, while Lewesdon may really be very nearly on the site of the original ridge of the watershed. The same process has taken place near Beaminster, where the spring-heads which furnish the headwaters of the Brit have un- doubtedly eaten deep into the Chalk and Greensand area, and there the escarpment is still receding, as the frequent scars of landslips testify. It will be seen, therefore, that the history of the evolution of the present physical features of West Dorset involves the consideration of many agencies and many conditional phases. Here, as elsewhere, rain, rivers, snow, frost, and heat have been the principal agents at work, but in order to understand how their operation has resulted in the particular arrangement of hills and valleys which we see around us, we must form some conception of the conditions under which — they started to work, and we must remember that their working powers have always been guided and modified by the changes in the | relative height of sea and land, those slow movements of upheaval and subsicence to which every portion of the earth’s crust has been repeatedly subjected. Rev. J. F. Blake—The Llanberis Unconformity. 169 TV.—A Revinpication or tHe Luanserts UnconrorMity. By the Rev. J. F. Buaxz, M.A., F.G.S.! Preliminary Remarks. IG a paper published in the Quarterly Journal of the Geological Society for 1893,? I gave an account of the evidence that led me to conclude that certain conglomerates and associated rocks occurring for some distance north-east and south-west of Llanberis, which had hitherto been considered to lie below the workable Cambrian Slates of that area, were in reality unconformable deposits of a later date than those slates. In the year 1894 Professor T. G. Bonney and Miss C. Raisin published in the same Journal® a controversial paper criticizing my statements and conclusions. It may seem rather late in the day to be replying to a criticism made so long ago, and reasons for the apparent delay must therefore be given. At the reading of their paper before the Society I welcomed it as an attempt to examine the district I had described, and it was only on reading it in full that I realized its true character. I was then just leaving for India, and though a large part of the criticisms might have been replied to at once, there were statements in it which could only be explained and accounted for after another visit to the ground, and this I was unable to make till my return, when I at once presented my reply to the Seciety—their Journal being, in my opinion, the proper place for it to appear in. As the Council, however, are of a different opinion, such part of my reply as refers especially to the criticisms on my work is here presented in a modified form with additional remarks. There was nothing in that paper which in any way suggested to my own mind that I might be wrong, but I can well understand that anyone reading it might believe that my conclusions were so ill-founded that a short visit to the district by another observer might suffice to upset them. My object, therefore, here is to show that it is not I but my critics who are in error. The question whether a certain conglomerate in North-West Carnarvonshire is conformable or not to the underlying rocks may seem at first sight to be of no great consequence, but it involves the larger question. as to where the base of the Cambrian system is to be drawn—that is to say, what beds are to be included in or excluded from the Pre-Cambrian series; and this is a matter in which some of the foremost of present and past geologists have interested themselves. This being the case it is probably unnecessary here to point out the bearings of the several factors involved. It will suffice to note what views of the subject have been taken by different observers, in order to show how far my own views or those of my opponents coincide with or differ from those of others. 1 The substance of a paper read to the Geological Society on December Ist, 1897, with additional remarks. 2 Vol. xlix, pp. 441-446. 3 Vol. L, pp. 578-602. 170 Rev. J. F. Blake—The Llanberis Unconformity. History of Previous Opinion. The older view expressed by Sir A. Ramsay in his “ Geology of North Wales”? (A) is too well known to require much explanation. He regarded the felsite here exposed as a single mass which had intruded into, and in places completely altered, the adjacent con- glomerate. He based his view principally on the fact that the matrix of the conglomerate closely resembles the felsite, even ‘to the porphyritic crystals, the passage between the two being quite gradual. We must not suppose that such a geologist as Sir A. Ramsay was misled in this matter, as some subsequent writers have suggested, by so simple a thing as the obscurity of the pebbles in an unweathered block. On the contrary, more than one of these writers have described the rocks in which his statements are verifiable as felsites. Such rocks may be seen near the Llanberis road, on the summit of the felsite crag in the tramway section, on the slopes of Clegyr, and on Mynydd-y-cilgwyn, and here certainly Sir A. Ramsay’s explanation is suggested, thongh further observa- tions, here and elsewhere, render it untenable. When, however, we reject it we must admit that a conglomerate can be deposited on a felsite in such a way that it is impossible to say where one begins and the other ends. His explanation also accounted for “the capricious variation of the strata adjoining the porphyry,” which otherwise might have suggested to him an unconformity. The first attempt to upset Sir A. Ramsay’s explanation came from Professor Hughes and Dr. Hicks, the latter publishing his views (B) in 1878.’ He considered (1) the felsite at Moel Tryfaen to belong to the same series as the rocks in the adit beneath the hill, and (2) both to be overlain unconformably by the conglomerate ; but he gave no proof of the latter conclusion beyond a supposed N.W. dip of the “metamorphic rocks,” the Cambrian conglomerate having, according to him, a N.E. dip. But he pointed out that the conglomerates contained pebbles ‘‘ appearing to resemble the rocks in siti near,” and stated of these conglomerates that “here, as in all other Welsh areas, they strongly define the base of the Cambrian.” Of the rocks of Llyn Padarn he says, “it is more than probable that we have in the series here some contemporaneous lavas,” and “‘the pebbles in the conglomerates are usually identical in character with the rocks below.” He does not, however, point out what is the nature of “the rocks below,” though they must have included the felsite. In 1879 Professor Bonney published a paper on the district (C).* It gave the result. of “working over parts of the district [including the Bangor area] on several days in September, 1878.” From | internal evidence it would appear that the author visited Moel Tryfaen and returned by the Bettws Garmon road, walked from Cwm-y-glo to Llanberis by the railway, and returned part of the 1 Mem. Geol. Survey, vol. iii. * Q.J.G.S., vol. xxxiv, pp. 147-152. 3 Q.J.G.S., vol. xxxv, pp. 309-320. Rev. J. F. Blake—The Lianberis Unconformity. 171 way by the road, climbing the slopes above, and also went along the tram-line on the other side of Llyn Padarn from the head of the lake to Llys Dinorwig. He accounts for the differences between himself and “ ihe officers of the Survey ” by their being “ occasionally misled by the superficial aspect of the rocks.” Part of this paper it is necessary to quote. Speaking of Moel Tryfaen, he says: ‘The conglomerate contains pebbles of the same purplish quartz-felsite, generally 2—4 inches diameter, but sometimes a foot or more, together with angular fragments of purple slate. On the western side about one-fourth of the fragments are felsite, the remainder slate—green and purple, and a dull green grit resembling one in the underlying series. “The fragments of purple slate are rather more numerous. on the eastern side. The strike of the conglomerate appeared to be about E.N.E. and W.S.W. : and the bedding, as it seemed to us, dipped to the N.N.W. ata inf angle, but . . it was difficult to be sure of this” [Dr. Hicks had made the dip N.E.]. The quartz-felsite he takes to be a lava- flow, because (1) it shows flow-structure in parts; (2) a band of slate is intercalated in it and is not wou LemoNSTy altered; (8) it is associated in places with an agglomerate. He also gives a section along the tramway by Llyn “Padarn, which will be referred to later on. One among his conclusions is that “further examination will probably discover more agglomerates, and perhaps further sub- divide the lava-flows,”’ endl in speaking of Moel Tryfaen, ‘“‘ where the quartz-felsite must be very thick,” says, ‘“‘appearances suggest that there is a marked physical break between this [the Cambrian conglomerate | and the subjacent sedimentary series.” Up to this time, therefore, the only alternative to Sir A. Ramsay’s view was, that there was a single conglomerate forming the base of the Cambrian, and that it lay unconformably on. or was separated by, a marked physical break from the rocks below, whether felsitic or sedimentary, whose fragments also its pebbles resembled: the only variation being that Professor Bonney figured the conglomerate in his tramway section? as conformable, but said nothing about it in his text. In 1885 Professor Green (D) described part of this section,’ which he considered to show that “the conglomerate rests on these rocks with the strongest possible unconformity.” As to the age of the conglomerate, he only says that it is ‘‘taken to be the base of the Cambrian rocks in that district.” At the reading of 1 All these reasons seem to me to have now disappeared. We have learned that flow-structure may be found also in an intrusive rock (see Sir A. Geikie in G, postea, p. 93), the “‘slate’’ is a greenstone dyke, and the agglomerate may be a fault breccia. Even the proof of the. felsite being of earlier age than the con- glomerate would not now, if that conglomerate is post- Llanberis, prove it to be non-intrusive, and there remains only the fact that it is always followed, in regular succession, by its own débris, or what is considered to be such, and ‘this seems sufficient. 2 Op. cit., p. 315. 3 Q.J.G.8., vol. xli, pp. 74-79. 172 Rev. J. F. Blake—The Lianberis Unconformity. this paper Professor Hughes expressed his agreement that here “the newer series” is “absolutely unconformable to the older,” and Dr. Hicks said that “from the present evidence it is clear that an unconformity does exist.” Professor Bouney, however, said that Professor Green’s reading of the section (which differed from his own) might be the correct one, but he felt very doubtful. It was this genera] consensus of recent opinion, that there were Pre-Cambrian rocks exposed in this district, that led me to examine it in connection with the Pre-Cambrian rocks of Anglesey, announcing my results in 1888'(H). At the time of writing that paper I was no better acquainted with this part of the district than other writers upon it, but I was led to accept the recent opinions (1) that the felsite was a lava-flow and not intrusive, and (2) that the con- glomerate to the east was derived from it. But no evidence had been given for regarding the conglomerate as the base of the Cambrian, and accordingly I considered it might be high up in that series. Nor could I then see proofs of unconformity at Moel Tryfaen, while the unconformity shown by Professor Green I could not deny, but I tried to discount it by quoting his opinion that it did not necessarily indicate any great difference in age.? I thus considered the felsite to be part of the Cambrian succession, in spite of accepting all that previous writers had given reasons for. As to the con- glomerate, quoting previous observers, I considered that the pebbles — were of Cambrian age, and yet took the containing rock to be one of the higher conglomerates in that series. In 1891 Miss C. Raisin traversed my conclusions as above (F).° In this paper, amongst many minor criticisms, she made one of great weight (in addition to the correction about the “ slate”). Speaking of Moel Tryfaen, she said: ‘“‘We should have to believe that at some epoch, after the deposition of one of Mr. Blake’s successive conglomerates, the slates of which we now speak were deposited, indurated, modified, and worn down to form some of the Moel Tryfaen pebbles—a process of rapid manufacture indeed.” This was used as an argument for an unconformity below the conglomerate, which she was then in favour of, even though she could not observe it in Professor Green’s section, where she con- sidered it as only “ locally absent.” Five days previous to the reading of this paper Sir A. Geikie treated of the district in his Presidential Address (G).4 He denied that the conglomerate forms the base of the Cambrian, or is un- conformable on the rocks below, and, in fact, he agreed exactly with my then published views. But he could not see the unconformity 1 Q.J.G.8., vol. xliv, pp. 271-290. * In this same paper I endeavoured to support the Cambrian age of the felsite by finding its base. Therein | mistook a squeezed relic of a dyke for slate, with the result that the section, which I thought proved my point, proved nothing, either for or against it. In a later paper (F) Miss Raisin did me the service of pointing - out this mistake, as I have much pleasure in acknowledging. 3 Q.J.G.S., vol. xlvii, pp. 329-342. 4 Tbid., Proc. Rev. J. F. Blake—The Lianberis Unconformity. 173 where Professor Green described it, and was not, therefore, forced as I was to discount its teaching. In 1892 I published a detailed account of the Cambrian succession (H),' from which it appeared that instead of there being only one Cambrian conglomerate at the base, there were several at different horizons in the series. The facts about the Llyn Padarn felsite and conglomerate were postponed to a later paper. This later paper (1), published in 1898,? is the one which has been criticized by Professor Bonney and Miss Raisin conjointly in the paper now being replied to (K).* Prior to the observations therein recorded, most of which were entirely new, I had considered that there was no unconformity beneath the Llyn Padarn — Moel Tryfaen conglomerate, except the supposed local one shown by Professor Green, but these observations forced me to conclude that Professor Hughes and Dr. Hicks were right in their conjecture that such an unconformity occurred, and that it indicated, in the words of Professor Bonney, a “marked physical break.” Notwithstanding this, I still agreed with Sir A. Geikie in considering that there were several conglomerates in the Cambrian series, each in relation to its own felsite, but I removed from that series the great one at Moel Tryfaen and Llyn Padarn. It thus appears that at that time the whole difference of inter- pretation rested solely on the question as to what were the rocks on which the conglomerate lay unconformably. Dr. Hicks supposed them to be Pre-Cambrian, because the samples he collected in the Moel Tryfaen adit seemed more altered than the Cambrian rocks with which he was acquainted. I held them to be part of the ordinary Cambrian series. I was accompanied in the examination of the adit section by Mr. Robert Lloyd, who has spent his life amongst these rocks and knows them well, and he recognized them at once by their local names. I also exhibited to the Geological Society samples of all that I collected there, without anyone claiming them as anything but Cambrian. But, of course, this difference was fundamental. If the con- glomerate in one place is unconformable to the rocks immediately below the purple slates, we may reasonably expect that in other places it will be unconformable to the latter also, as they follow the former in regular sequence, and in this case the whole proof of there being anything Pre-Cambrian here is entirely destroyed. Under these circumstances it is certainly remarkable that Professor Bonney and Miss Raisin, in their criticism upon my paper, do not attempt to show that the rocks in the Moel Tryfaen adit are Pre- Cambrian, but endeavour to demolish my stratigraphy, in which, if successful, they would destroy their own former views and ap- proximate to those which now, on further evidence, I have discarded, and which were nevertheless equally fatal to the idea of there being any proof of the existence of Pre-Cambrian rocks in the district. 1 Q.J.G.8., vol. xlvili, pp. 243-262. 2 Q.J.G.S., vol. xlix, pp. 441-466. 3 Q.J.G.8., vol. t, pp. 578-602. 174 Rev. J. F. Blake—The Llanberis Unconformity. The various views on this district may now be thus summarized : A. A general unconformity indicates the commencement of a new series.— All. B,. There is no unconformity in this district. — Ramsay ; at Moel Tryfaen, Bonney, Raisin. B,. The unconformity is local only.—Getkie, formerly Blake. B,. The unconformity is general. — Hughes, Hicks, Blake ; formerly Bonney, Raisin. Conclusion 1. There is no break in the series here.—Ramsay, Geikie, Bonney ? Raisin ? formerly Blake. Conclusion 2. The great conglomerate forms the base of a new system.—Hughes, Hicks, Blake; formerly Bonney, Raisin. C,. The Moel Tryfaen conglomerate is Cambrian, therefore the underlying beds are Pre-Cambrian.—Hughes, Hicks ; formerly Bonney, Raisin. C,. The beds below the Moel Tryfaen conglomerate are Cambrian; therefore there is no evidence of Pre-Cambrian rocks here, and the age of the conglomerate is doubtful.— Blake. Professor Bonney and Miss Raisin’s general Objections. The authors commence by characterizing my conclusions as “a new and revolutionary hypothesis”; but it will be seen from the foregoing account that the idea of an unconformity is by no means new. The nature of the rocks in the Moel Tryfaen adit can scarcely be called a “hypothesis,” and it is this that is revolutionary in its results, the further extension of the unconformity, which no doubt is new, being thus rendered quite natural. My suggestion also of there being more than one felsite, had been anticipated by Professor Bonney in C. As a first objection my critics ask: “To what epoch (from the Menevian onwards) do these so-called Post-Llanberis sediments belong, and where in the adjacent districts may we find beds that can be correlated with them?” “Of this problem,” they say, I have not ‘succeeded in offering a solution.” When they wrote this they cannot have considered my words (p. 465): “It seems to me most probable that they are extensions of the immediately overlying rocks.” These overlying rocks (the Bronllwyd Grit and_ its associates) do not belong to any epoch from the Menevian onwards, but lie below that formation and below all fossiliferous rocks, except the Penrhyn pale slates with Conocoryphe viola. ‘The authors have totally misunderstood my suggestion ; moreover, that suggestion about the probable age of the conglomerate may be wrong without affecting the question of the unconformity. Next they take me to task for saying that we must see whether- this unconformity be local or not, for according to them “ it can be no local phenomenon.” Plainly it is because I take for granted that a ‘marked physical break” (Bonney) can be no local Rev. J. F. Blake—The Llanberis Unconformity. 175 phenomenon that I propose to see whether the supposed break is local or not by way of testing its existence. The next difficulty is “the necessity of twice uncovering the felsite,” which, they say, I have “not even considered.” Certainly I have not. Why should not felsite be uncovered twenty times in the course of its history ? As I do not understand what the difficulty is, | may be wrong in supposing it to result from a mixture of ideas. It may be their idea that there is in this district an unconformable conglomerate at the base of the Cambrian series, and it is my idea that there is an unconformity above that series. I do not hoid both. As to all the conglomerates but one, I accept Professor Hughes’ and Sir A. Geikie’s explanations as to how a contemporaneous lava-flow may be denuded before it is covered up by any other stratum, and thus yield its pebbles to an overlying conglomerate. It is only when the conglomerate has to lie on the felsite unconformably that the latter wants uncovering. The next difficulty is thus expressed: “Curiously enough the Llanberis strata, though they have been so completely planed down, have not contributed any large amount of fragments; only ex- ceptionally do we find these or slaty pebbles of any kind, as, for example, at Moel Tryfaen.” Here the authors give themselves completely away. If there be a single pebble, exceptional or other- wise, really deposited with the conglomerate and derived from the Llanberis strata, then the former must be younger than the latter. Probably the authors do not mean what the words imply, but for “these” we must understand ‘‘ pebbles resembling these, but not really derived from them.” Even then the statement reads curiously with reference to Moel Tryfaen, after Professor Bonney’s description in C, that about three-quarters of the pebbles on the western side are “slate, green and purple,” etc., as quoted above, while “on the eastern side the fragments of purple slate are rather more numerous.” He then believed in the unconformity. The statement, however, that the Moel Tryfaen conglomerate is exceptional in containing slate pebbles is based on defective information. The slopes of Y Big] show, in certain parts of the conglomerate, quite a number of purple slate fragments, of such large size and so angular that I really cannot suppose them to have come from any distance ; and the workable slates close by are just like them. They are found also on Mynydd-y-cilewyn and between Moel Rhiwen and Moel-y-ci. We must remember, too, that purple slate is not a kind of rock likely to be left in large fragments far from its source of origin; it would soon break down into mud and form a new rock like the original. Of this we find several examples, which render the stratigraphy difficult. So far from the alleged absence of pebbles of rocks like the adjoining ones being a difficulty, their frequent presence and their distribution are strongly in favour of an unconformity, as formerly argued by Miss Raisin. It is these slate pebbles that distinguish, when present, the great conglomerate from others which are intra- formational. Sir A. Geikie proposed to account for them by the 176 Rev. J. F. Blake—The Lianberis Unconformity. breaking up of the circumjacent deposits during a volcanic eruption, but this explanation is untenable because, as pointed out by Dr. Hicks, the pebbles are of rocks already cleaved. The conglomerate runs in a long line, and its pebbles change character with the rock near which it lies. Near the felsite it becomes most felsitic. On Y Bigl and further north, as also at Moel Tryfaen and Mynydd-y- celowyn, where it lies nearest purple slate, the fragments like that rock are most abundant, and where at Moel Tryfaen it approaches nearest the upper side of these slates, it contains strange, un- recognizable fragments. In this it shows the character of a shore deposit. Although the general objections of my critics are thus disposed of, I do not in the least demur to their conclusion, that “the detailed evidence ought to be of the strongest and clearest nature if it is to establish the supposed unconformity.” That is just what it is. - The Moel Tryfaen District. This is the district in which Professor Bonney (C) argued that there was a marked physical break, and Miss Raisin (I) that we see here the base of a series. But now that I give LeaUIH proofs of the unconformity they cannot believe it. Dealing with the summit conglomerate and the aril amount of | any conglomerate in the adit section, these authors say ‘‘ there seems on our theory no other explanation possible than that this con- glomerate is fanlted out, and the broad outcrop at the summit might be partly due to such disturbance.” We are not told, however, what “our theory” is, nor where the conglomerate is faulted out from, nor how much of the broad outcrop “might be” due to such disturbance. This “explanation” is put forward without any detail that should give us the slightest clue to its meaning, and if we try to guess we are confronted with the puzzling remark, “ this seems suggested by the changed dip in the associated green grits on the summit.” What the dip was previously and how determined we are not told, so I think it useless to speculate on their meaning. The authors disagree with me when I say that there is no green grit on the summit. I will only remark that the green grit seen by them is not the green grit which IJ referred to, which was one occurring between the conglomerate and the purple slates, while, so far as I can judge by the dip given, their “green grit” is part of a small band of false-bedded grit associated with a different kind of conglomerate of white weathering pebbles, near the opposite side of the outcrop. Here one block shows the dip they state, N.N.W..,. while an adjacent block shows the opposite, 8.8.E. Referring to my description of the wide spread of conglomerates and grits on the north side of the hill and their generally horizontal trend in an east-and-west direction, the authors differ from me again, at least by implication. I stated that there was a line of crags showing a dip of not more than 5° to the east, and also in a lower part a lenticle of fine grit running almost horizontally Rev. J. F. Blake—The Lianberis Unconformity. ie in a conglomerate. It is not positively stated that these observations are incorrect, but only that “ we took the dip on several blocks and surfaces, of which four at least were clearly shown varying from 15°—25° generally to the S. of E. or 8.H.” ; from which it is left to be inferred that these statements are incompatible with mine. But they are not. J have seen “blocks and surfaces” showing the dips mentioned, but they are isolated blocks lying on the eastern slope of the hill, and it is not certain that they are in siti. I did not even look for dips on such blocks, as dips are worse than useless unless the rocks are certainly in sitd. But even in that case these dips, combined with the more persistent ones of the crags, would not affect my argument to any material extent. But with such rocks as these, and so exposed on the slopes of a rounded hill, it is not by isolated dips, which are liable to all kinds of accidents, but by the direction of the outcrops that the strike may best be determined. In this case, if we walk on a level line round the base of the north side of the hill a little above the pathway, we keep on conglomerate, but if we anywhere mount a little and take another contour-line, we keep upon grits. This would indicate that the junction between them, i.e. bedding of both, was not far removed from the horizontal in a direction across the hill. The further remarks about this district are—(1) That the con- glomerate of the lower crags is not like that of the summit, as it does not contain the large slate pebbles. It is true that the pebbles of cleaved rock with the appearance of slate are not so large as in the latter, but there are many of them. (2) That whereas I said of a certain area that it was all covered with conglomerate and grit, in fact no small part consists of unbroken sward. This is only true of that part which I called “the lower slopes,” and which I dis- tinguished from the part all covered with conglomerate and grit. (38) That it is remarkable that the conglomerate, if unconformable, does not spread over on to the purple slates. This has not been proved to be the case, and if true is easily explained. The fault which bounds the purple slates is probably a thrust-plane which lifted them and their covering above the level of the conglomerate on the other side, and they have been worn back to that level by denudation, which necessarily first removed the conglomerate. Probably also ice has swept all débris away. In this district, then, my critics have brought no valid objections against my conclusions, and have failed to propose any reasonable alternative. Meanwhile they have not touched the argument from the great spread of the conglomerate and its associates over a very wide area on the surface of the hill, while nothing but a 3 feet band is found in the adit,! nor the still more cogent argument that, whereas the conglomerate here lies on, or is next to, a great mass of banded slate, in the neighbouring hill of Mynydd-y-cilgwyn it hes entirely on felsite, and continues round to the western side of it. 1 I might add that this is not quite like the summit conglomerate, but such arguments are of little value. DECADE IV.—VOL. V.—NO. IV. 12, 178 Reports and Proceedings—Geological Society of London. But I cannot understand what they would gain by success in their contention. If instead of one unconformable conglomerate it were granted that there were two or three conformable ones, they would belong to the adit series, or to the purple slate series, or to both, but in no case could they be the base of the Cambrian system, or give any assistance in proving the existence of Pre-Cambrian rocks in the neighbourhood. (To be continued.) Isa SOpsws) JNaN~p) 1-35 OO2I aD scINiGrS - GeoLocicaL Socrrry oF Lonpon. J.—February 2, 1898.—Dr. Henry Hicks, F.R.S., Presidents in the Chair. The President announced that Dr. Charles Barrois, Secretary of the Organizing Committee of the Highth International Geological Congress, which will be held in Paris in 1900, would shortly come to London to invite the Geological Society to the Congress, and to consult the Fellows with regard to the proposed excursions and the subjects of discussion. The following communications were read :— 1. ‘Contributions to the Glacial Geology of Spitzbergen.” By B®. J. Garwood, Esq., M.A., F.G.S., and Dr. J. W. Gregory, F.G:S. The extent of glaciation of Spitzbergen has been exaggerated, for there is no immense ice-plateau, but normal glaciers with some inland sheets and Piedmont glaciers. These differ from Alpine glaciers, as they are not always formed from snow-fields at the head, and though some of the glaciers (as the Baldhead Glacier) have tapering snouts in front, most have vertical cliffs. _Chamberlin’s explanation that the latter are due to the low angle of the sun is insufficient, and they seem to be caused by the advance of the ice by a rapid forward movement of its upper layers. The ice of these upper layers falls off and forms talus in front, over which the glacier advances, carrying detritus uphill with it, and producing a series of thrusts. The Booming Glacier illustrates cases of erratics carried in different directions by the same mass of ice. The deposits of the Spitzbergen glaciers are of four types :— (1) moraines of Swiss type; (2) those formed mainly of intraglacial material; (8) those formed of redeposited beach-material ; (4) de- posits of glacial rivers and reassorted drifts. ‘The materials of the second are subangular and rounded ; scratched and polished pebbles and boulders are abundant, and the fine-grained matrix, which is frequently argillaceous, is often well laminated and false-bedded. Some of these drifts are stratified, others unstratified, and contorted © drifts occur. This type of moraine is remarkably like some British Boulder-clay. The third class is sometimes formed by land-ice, at other times beneath the sea; the latter shows stratification. The Reports and Proceedings—Geological Society of London. 179 superglacial and intraglacial streams, so far as seen, were usually clear of drift. Under the fourth head an esker in a tributary of the Sassendal is described. . The direct geological action of the marine ice is of four kinds: transport of material, contortion of shore-deposits, formation of small ridges of boulder-terraces above sea-level, and striation, rounding, and furrowing of rocks along the sea-shore. Traces of former glaciation are described in the case of the Hecla Hook beds, and of certain beds of late Mesozoic or early Cainozoic age in Bunting Bluff. ; Under the head of general conclusions, the authors state that they have discovered no certain test to distinguish between the action of land-ice and marine ice; that there is no evidence to prove that land-ice can advance far across the sea; and that there is evidence, which they regard as conclusive, of the uplift of materials by land-ice. They note that the mechanical processes connected with the advance of the glaciers are of three kinds. All the material seen transported by the glaciers was superglacial or intraglacial, and not subglacial. Some striation of intraglacial material is caused by differential movement of different layers of ice. The advance and retreat of the Spitzbergen glaciers is very irregular, and apparently due to local changes. The observations of the authors support the views of those who ascribe a limited erosive power to glaciers. Lastly, the theory that glacial periods occurred as a consequence of epeirogenic uplifts receives no support from Spitzbergen. 2. “Ona Quartz-rock in the Carboniferous Limestone of Derby- shire.’ By H. H. Arnold-Bemrose, Esq., M-A., F.G.S. The paper describes the occurrence in the field and the micro- scopic structure of a rock consisting essentially of quartz, which is found in the Mountain Limestone in several localities. It occurs in irregularly-shaped bosses and veins, and shows no signs of stratification. Its close association with a quartzose limestone, which in turn passes into an ordinary limestone with few, if any, quartz-crystals, leads to the inference that it is a silicified limestone. The microscopical structure of a number of thin slices of these rocks is described. The quartz-rock is seen to be made up of quartz-grains which generally interlock closely, but sometimes possess a crystalline outline and contain zones of calcite. Fluor is occasionally present. The quartzose limestone is usually a foraminiferal limestone containing a large percentage of quartz, which occurs as separate crystals and as aggregates of crystals. The latter and the small quartz-veins have a structure similar to that of the quartz-rock. The former often contain zones of calcite and penetrate organisms. The residue consists of quartz-crystals. The author considers that the quartz-rock is not a gritty lime- stone, altered by the growth of crystalline quartz around the detrital grains, but that it is a limestone replaced by quartz. The gradual 180 Reports and Proceedings—Geological Society of London. passage from the quartz-rock through a quartzose limestone to an ordinary limestone, the presence of chert, of part of a foraminifer, and of pieces of quartzose limestone in it, support the opinion that it is an altered limestone. J].—Annuat Generat Muerine.—February 18, 1898. Dr. Henry Hicks, F.R.S., President, in the Chair. The Secretaries read the Reports of the Council and of the Library and Maseum Committee for the year 1897. In the former the Council referred to the uninterrupted financial prosperity of the Society and to the continued increase in the number of Fellows. During 1897 the number of Fellows elected was 59: of these 41 qualified before the end of the year, making, with 13 previously elected Fellows, a total accession of 54 in the course of the twelve- month. During the same period, the losses by death, resignation, and removal amounted to 51, the increase in the number of Fellows being 3. ; The total number of Fellows, Foreign Members, and Foreign Correspondents, which on December 31st, 1896, was 1,329, stood at 1,333 by the end of 1897. The balance-sheet for the year 1897 showed receipts to the amount of £3,610 19s. 3d. (including a balance of £768 3s. Od. brought forward from the. previous year), and an expenditure of £2,887 16s. 3d. There was an actual excess of expenditure over current receipts of £45, but the excess was entirely due to expenditure of a non-recurring character, and there still remained at the end of 1897 a balance of £723 3s. available for the extraordinary expenditure contemplated in the estimates submitted to the Fellows. The completion of Vol. LIII of the Society’s Quarterly Journal was announced, as also the publication of No. 4 of the Record of Geological Literature added to the Society’s Library, and of Part II of the General Index to the first Fifty Volumes of the Quarterly Journal. An address was presented to Her Majesty by the President and Council, on their behalf and on that of the Fellows, on the occasion of the Sixtieth Anniversary of her Accession; and three delegates were nominated to represent the Society at the International Geological Congress held at St. Petersburg. The attention of the Council had been drawn by Sir Archibald Geikie to the manuscript, in the Society’s possession, of part of the Third Volume of Hutton’s “Theory of the Earth.” He had freely offered his services as editor, and it was proposed’ to print and~ publish the work during the present year. Reference was also made to the work done by the Committee appointed in connection with the International Catalogue Committee, and to the Index slips issued with the current number of the | Quarterly Journal. In conclusion the awards of the various medals and proceeds of donation funds in the gift of the Society were announced. Reports and Proceedings—Geological Society of London. 181 The report of the Library and Museum Committee enumerated the large additions made to the Society’s Library during the past year, and referred to the continuance of the work of labelling and registering the specimens in the Museum by Mr. C. Davies Sherborn. In handing the Wollaston Medal (awarded to Professor Ferdinand Zirkel, F.M.G.S., of Leipzig) to Mr. J. J. H. Teall, for transmission to the recipient, the President addressed him as follows :—Mr. Teall :— The Council of the Geological Society have this year awarded the Wollaston Medal to Professor Zirkel, as a mark of their appreciation of the great services which he has rendered to Geological Science, especially in the, department of Petrology. His ‘“ Lehrbuch der Petrographie,’’ the first edition of which was published more than thirty years ago, is an indispensable adjunct to the library of every petrologist. A comparison of the two editions of this monumental work, the second of which has only recently appeared, illustrates in a most striking manner the enormous advance which has taken place in petrographical science during the interval—an advance in no small measure due to the influence exerted by Professor Zirkel, both as a teacher and as an original worker. His classic memoir on the ‘‘ Microscopic Structure and Composition of Basaltic Rocks ’’ was one of the first publications in which the results of the examination of an extensive series of microscopic sections were made known. It marks an epoch in the history of petrography, not only because it greatly extended our knowledge of this important group of rocks, but also because it gave a great stimulus to the study of thin sections under the microscope. It must always be a source of gratification to British geologists that this important work was dedicated to our distinguished Fellow and revered master, Henry Clifton Sorby. It is impossible for me to review all Professor Zirkel’s important contributions to Geological and Mineralogical Science, but there is one other that I cannot pass over in silence. I refer to his ‘‘ Geological Sketches of the West Coast of Scotland.’’ In this memoir Professor Zirkel applied the methods of microscopic analysis, for the first time, to the wonderful records of Tertiary volcanic activity which abound in that region. As an original observer he has made his mark in the history of our time, and as a Professor he has won the esteem and affection of many enthusiastic students. It only remains for me now to request you to transmit to Professor Zirkel this Medal, and at the same time to express to him our great regard and our sincerest wishes that he may long enjoy health and strength to continue his important pene in those branches of Geological Science tor which he has already done so much. Mr. Teall, in reply, read the following letter, which he had received from Professor Zirkel :—‘‘ Mr. President,— ‘“The honourable award of the Wollaston Medal is for me one of the most gladdening events of my life. Yet I cannot say whether I am more pleased or surprised at the unexpected announcement that I should be considered worthy of so brilliant a distinction, which has been bestowed by this highest tribunal of Geology only on the most illustrious British and Foreign votaries of the science. But to-day all feelings are merged in one of gratitude to the Members of the Council, who have taken so generous and favourable a view of my modest labours. As, much to my regret and disappointment, I find myself unable to attend the Annual Meeting, I must trespass upon your kindness to express by these written words my heartfelt thanks and best acknowledgment for the great honour conferred upon me, of which the most ambitious may well be proud. I receive the Medal asa token of indulgence and encouragement, and it will be an incentive to me still to strive to be more worthy of it and of your confidence. Probably I never should have been able to do what I have done, but for the wise example and kind instruction of my old master, Henry Clifton Sorby. The tie of personal friendship which connects me with so many fellow-workers in your country since those bygone days, when Murchison, Lyell, and Ramsay favoured the young foreigner with their attachment—this tie will be strengthened to-day, and the Geological Society's prosperity and usefulness will never cease to be the object of my warmest wishes.”’ 182 Reports and Proceedings— Geological Society of London. The President then handed the balance of the proceeds of the Wollaston Donation Fund (awarded to Mr. HE. J. Garwood, M.A., F.G.S.) to Mr. A. Strahan, for transmission to the recipient, addressing him as follows :—Mr. Strahan,— At the last Meeting of the Geological Society we had the pleasure of listening to a communication by Mr. Garwood and Dr. Gregory which adds much to our knowledge concerning the Glacial Geology of Spitzbergen. Last year he also gave an address at one of the ‘‘ At Homes’”’ of the Society, which was highly appreciated by those present. These amply testify to his ability to carry on explorations in difficult regions, where strength of purpose and special training are indispensable to success. Other geological questions have also occupied his attention; and I may here mention the paper by him in the Geological Magazine on ‘‘ Magnesian Limestone Concretions’’ as an interesting contribution to a vexed question, and his paper and reports on Carboniferous Fossils, the result of much labour among the Carboniferous rocks of the North of England. The Council, in making him this Award, hope that it may act as a stimulus to further researches in those fields in which he has already shown such marked ability, and that he will accept it also as a token of appreciation for what he has already accomplished. Mr. Strahan, on behalf of the recipient, read the following reply :—‘“‘ Mr. President, — ‘ Co — yy DO CU > Cc | oo OD i oO S __. ><> Z . TT . ES — . — <> ee NZ WZ Vw S _ a Zs < iS ~ — SS — ~ NS: Q << VS YEN: & aS SZ a Me ESS - ASS — WN - _ ] - OC -— oe e - me < c _ Kc Cw ‘ — — Ss SaaS 2 NZ < MZ Do <>) pO Se LE RIENEG, a UN ON wT Sc AS — of oC >. : _ Sec PC So aT WO. ~~ LEEW Se DR EY ae Zo SU Ae. SZ Se RO oo. 2 WER _ GEGEN WZ G DO WO SZ NUE Ss NS W'S a Zz pS j - wo DO > - Cc — . i Si < ~O] y _ . a SENG SS -. < J : | . ~ << ep: Ss 2D os oO _. a _. - < <> > — : ee ~ 2 OZ Ne GA Wo RS oS Gy RO cy V7 NS - — C77 Ce PROT Za > Z | S _. - a oo) 7S iN. oy >< a _ ec * Sir H. H. Howorth—Surface Geology of N. Europe. 195 by two coastal plains. The high plateau of Mexico, with levels up to 10,000 feet, here descends for a distance of 60 to 80 miles, to levels of 2,000 to 4,000 feet, and at the divide is (as already stated) only, about 1,006 feet above the level of the ocean ; but on both sides of the saddle thers are. base-levels of lower altitudes. ‘The rock consists of earthy sandstone ; and on the Pacific slope facing the city of Tehuan- tepec are old sea- ‘cliffs and caves at levels of .400 feet. The floor of the divide is traversed by a ‘‘ geological canal,” ata level of 776: feet above’ the ocean, and. is fcowened iby enamel from, 4 to 8: feet in depth, of quartz and soft sandstone pebbles, the latter being well rounded ; this gravel is more thinly: scattered over the adjoining slopes to a height-of 150 feet. The isthmus was evidently: swept over by ocean-currents passing through the straits during sub- mergence; and its elevation has been so recent that only short canons have been. cut into the base-levels and. terraced plains adjoining. Another line of communication was recognized at the pass of Tarifa, a dozen miles eastward of that of Chivela above described; and there are other current-swept depressions in’ this region through which the waters on both sides are considered: to have had intercommunication; though at higher levels. It should be added that the stratified gravel of the divide:is continuous with that covering the terraced plains on the Gulf side of the divide... ° The author considers ‘that this oceanic connection was as old. as the Columbian (Mid-Pleistocene) epoch, and. was contemporaneous with the great emergence of the: Antillean Continent’ and Hastern America. It isa splendid illustration of the Lyellian- doctrine of the interchange of. land and sea, which geological phenomena bear testimony to from early, down to recent, times, and which serves as ai key to many problems in terrestrial physics. Finally, it must not be forgotten that the biological evidence of the former oceanic com- munication across the Isthmus of Panama is not less clear than is the physical. The late Dr. W.'B. Carpenter identified 35. species of molluscs, out of 1,400 Pacific forms, as occurring on the Atlantic side ‘of ‘this region; the number having. been since ‘increased: to 100 species, by the observation of Mr. Charles '. Simpson ;: while, according to the late Dr. G. B. Goode, there is absolutely: no resemblance between tae eee: -water fishes on the two sides of Central America. rie Bp, SeeracE GmoLoay or THE NortH oF EUROPE, AS ILLUS- TRATED BY THE ASAR OR OsAR OF SCANDINAVIA AND FINLAND. By Sir Henry H. Howorrn, K.C.1.E., M.P., F.R.S., F.G.S. | | PLATE VII. J N.a previous paper I ventured to emphasize the opinion, now very generally held, that, whether by a gradual. process, or, spas- modically, the Northern and, Central parts, of Scandinavia, have been rising from the sea-level since Tertiary times, and that, so far as we know, this rise has not been interrupted by intervals when the movement has been one of depression. The movement has, in fact, he Sue Jal, Jee, Howorth—Surface Geology of N. Europe. been constantly in one direction. If this be true, it follows as certainly as any physical fact follows its efficient cause that, other conditions being the same, the climate of Scandinavia, like that of Greenland, has been continually growing more severe, and is more severe now, than it was when the higher Norwegian raised beaches were deposited. The other conditions, however, have, so far as we can judge, not been uniform. One of them, and that a very important one, has in all probability altered, and that is the one which gives Norway and Britain their exceptional climate, and which diverts the isothermal lines of Western Europe from their normal route across Asia and America in places on the same latitude. This is the Gulf Stream. There are very strong reasons (and I have formulated some of them in my “Glacial Nightmare ”’) for believing that at the close of the Tertiary period the so-called Gut of Florida was blocked by solid land, and in consequence the warm waters of the Gulf of Mexico did not then get into the North Atlantic. If the Gulf Stream were non- existent, it is clear that the climate of the two sides of the Atlantic would be more alike than they are now along the same latitudes. That this was so is proved by the more Arctic types of molluscs which then lived on the coasts of Scandinavia and Scotland, and by the evidence of the existence of Alpine and Arctic plants at lower levels and in lower latitudes in Western Hurope, as shown by Nathorst and C. Reid. This conclusion is not only reasonable, but seems incontrovertible. It does not mean that North-Western Europe was then dominated by a Glacial climate and Glacial con- ditions, but only that it was more or less assimilated in regard to its climate to Canada and New England. As we have also seen, the evidence is very strong and conclusive, and has convinced almost every Swedish geologist, that not only has the greater part of Scandinavia and Finland risen greatly in altitude in the last geological period, but that this wide area has in a large measure been actually submerged under the sea since Tertiary times, and that its rise after this submergence was the last great fact which affected its surface. . I have argued that it was this submergence which did so much to polish and mammillate its rock-surfaces, effects which I hold to be the results in a very large measure of the eroding forces of the sea in a tempestuous latitude, and not of the hypothetical ice-sheet of which we have read so much. I will add another argument to those already used. If the terraces on the Norwegian coast really mark, as the Norwegian geologists argue, the differential rate of elevation of the coast, which has caused the cutting back of the cliffs to be — more rapid at one time than at another, it is clear that the polished rock faces of Norway cannot be due to anything but the corroding sea, for these faces have been worn back many feet while the coast has been rising, and cannot therefore retain any polish or smoothness ~ they may have acquired in the times preceding the upheaval. If they were polished by ice, the ice must have acted, not before, but after the elevation, which is a reductio ad absurdum. Apart from Sir H. H. Howorth—Surface Geology of N. Europe. 197 this, the facts presented by the general contour and face of the country seem to me to inevitably point the same lesson. Whether we examine the string of islands which fringe so much of the coast of Scandinavia, and which project from the surrounding water like so many gigantic whales’ or porpoises’ or turtles’ backs ; or whether we examine the thousand islands of the Malar Sea or the Aland Archipelago, with the same contours, or the mammillated surfaces which the gneissic and granitic rocks of the interior districts of Sweden and Finland bear, they seem to me to present a complete parallel to the contour of the islands of the Arctic archipelago north of America, and of the islands off the coast of Greenland, where the lines of drift wood and the stranded whales far above high-water most conclusively point to the whole land having recently risen from the sea. In these latter cases, the Arctic navigators who have seen the phenomena, and the geologists who have described their voyages, have agreed that the North American archipelago and the islands off Greenland have had their contours smoothed and rounded by that most effective of denuding agencies, a shallow ocean loaded with gravel and other débris, and not by an ice-sheet, which does not in fact exist there. Nor, to take another illustration, can we separate in any way, it seems to me, at Trollhattan and elsewhere the polishing and smoothing of the interior and of the lips of the Giants’ Cauldrons, which are confessedly the result of the aqueous action just named, from the polishing of the inclined rock-surfaces on which they occur. There is absolute continuity between them. ‘They all seem to me to concur with the upraised shell-beds, the great masses of false-bedded and stratified sands on the wide upland plains of Dalecarlia, and the other evidences which have been collected by the Swedish geologists, and to which I have referred in a previous paper, to show, not that the country has been swathed in ice, but that it has recently been the bed of a shallow and tempestuous sea. This conclusion is of the highest importance. It is not, of course, new. Without going back to the primitive geologists of the early part of the last century, who wrote before the incubation of the Glacial monster, it struck some of the very earliest critics of that theory, who had examined the problem very thoroughly on the ground itself. Bohtlingk, an experienced observer and a great traveller in Lapmark and Finmark, to whom we owe the conclusive evidence against polar ice-caps, says: “In Scandinavia, Finland, Lapland, and the surrounding countries we find, to the height of 800 feet, the most unquestionable marks of the constant retreat of the sea occasioned by a continued rise of the land. In consequence of this circumstance Scandinavia, during the first half of the alluvial period, was still an island, and the tongues of land of Russian Lapland, Finland, Esthonia, the government of Olonetz, as well as those parts of the government of Archangel situated to the east of the White Sea, were covered by the sea,” etc. (Hd. Journ., vol. xxxi, 1841, pp. 354, 355.) Robert, the very able geologist of the Recherche Expedition, writing as far back as 1848, says: ‘La mer me semblait polir, WS Sip Jel JL, Howorth—Surface Geology of N. Europe. canéler, creuser, rayer des roches de manieére a leur faire prendre la physionomie de ceux qui s’offrent aujourd’hui un peu au dessus de son niveau sur toutes les cétes de la Scandinavie.” Elsewhere he concludes that the sea once occupied a large part of Russia, and that Scandinavia then formed an archipelago. I have myself zigzagged across Sweden in various directions on my recent third visit to that country, and been continually impressed by the same conclusion. | The most powerful and important evidence has yet to be quoted, however, and it is forthcoming from what every intelligent person, who has traversed Sweden with the view of studying its recent geology, must consider to be in their way the most interesting and stupendous phenomena probably in the world: I mean the Swedish asar or osar. J am writing this paper in the very midst of them, and have had some special opportunities of examining them. The latest writer on Swedish geology, and one of the aiieees Nathorst, in his ‘Sveriges Geologi,’ published in 1894, after examining the various hea sea saline have been forthcoming to explain hein. has to confess that the problem is still unsolved. To use his own words, “‘vilja vi dock pa samma gang uttryckligen betona, att vi annu icke betrakta fragan sasom slutligen afgjord ” (op. cit., p. 248)—“ we must expressly state that we cannot consider (or look upon) the question as finally settled.” The asar are such a notable feature in the landscape of Sweden that it is not surprising they should have been observed and their peculiarities described at an early period. Their main features were, in fact, pointed out by Swedenborg at the beginning of the last century, and have been enlarged upon by every succeeding explorer. The Swedish geologists divide the asar into two classes— the asar properly so called, built up of masses of rolled stones, and the sand-asar, composed chiefly of sand. While it is easy to find specimens of each of these, it is also very easy to find others where masses of rolled stones and beds of sand or of tough clay or brick- earth pass into each other very much as they do in the Cromer cliffs. A good example is the fine as upon which Upsala is built, and in which we can study the internal structure admirably, since it has been recently excavated right through (vide Pl. VII). There we can see in the course of a few yards the passage from a mass of rounded boulders into sand. The sand in some places is almost continuous, and in others has banks of clay intercalated in it. The contour of the asar, as Swedenborg long ago pointed out, differs with the nature of their contents, the stony asar having steep sides, while the sandy ones have much rounder outlines. The stones which form such a great part of the asar (except certain specimens ~ occurring in their upper parts) are invariably rounded and water- worn, and would be well described by the phrase applied to some of the East Anglian gravels, viz. “cannon-shot gravel.” The asar are found in all parts of Sweden from Scania to Norland, and in — Hinland and Northern Russia they form, as is well known, huge banks and ramparts. In some cases they run with great uniformity in shape and breadth for long distances, their direction being Sir H. H. Howorth—Surface Geology of N. Europe. 199 wonderfully continuous. So uniform are they that, as Brongniart pointed out, the roads in some places, as from Upsala to Wendel, from Hnkoping to Nora, from Hubbo to Moklinta, etc., run along their crest. Sometimes they spread and widen out a little, forming nodes like so many knots on a cord. Frequently the continuous line is interrupted by a gap or a series of gaps, so that instead of a uniform bank there are a number of huge circular or oval mounds. They consist generally of a main trunk, with a number of small subsidiary lateral branches running into them like the affluents of a river, aud sometimes they have satellites attached to them in the shape of eskers and kame-like mounds. ‘They are as sharply marked off from the adjoining plain on either side as a railway embankment is. In some cases, notably in Finland, they do not run in parallel lines, but vary in direction, sometimes even crossing each other, but in Sweden their direction is singularly parallel, as may be seen from the admirable maps published by the Swedish geologists, notably that by Tornebohm. The enormous size and cubical contents of these gigantic mounds can only be appreciated by those who have seen them on the spot and followed them for miles. According to Erdmann, the well-known Upsala as, which runs from the mouth of the Dalelf to Sddertom, south of Stockholm, is about 200 kilometres long. The as of Koping, as far as it is at present traced, from Nykdéping to the Dalelf, is about 240 kilometres in length. The as of Enképing runs from near Trosa in Suder- mannia to Loos in Helsingland, and is from 300 to 340 kilometres long, while the as of Badelunda, running from Nyképing in Suder- mannia to the parish of Réattvik in Dalecarlia, is about 300 kilometres long. According to Erdmann, the asar west of the watershed between Lake Wenern and Lake Wettern run N.N.E.-S.S8.W., while east of that line they run from N.N.W. to 8.S.E. Erdmann also gives the elevation at which some of the principal asar have been traced. “In Jemteland, N.and N.W. of Storojo, to 1,000 or 1,200 feet; in Herjeadal, near Hede, to 1,300 or 1,400 feet; in Daleearlia, in the parishes of Malung and Idre, to between 1,000 and 1,300 feet; in the government of Elfsborg, in Vestrogothland and east of Ulricehamm, to 1,100 feet; at Jonképing, in Smialand, near to Lake Almesikra, to about 1,000 feet ; but Tornebohm informed Mr. Geikie that in the northern parts of the country they occur at an elevation of 2,000 feet.” ‘Their height varies, the average being about 50 or 100 feet high, but in many places they run up to 100 metres or more, while they sometimes sink to 20 or 80 feet. Their breadth, too, varies, the normal breadth being from 80 to 50 paces, but in some cases, as at Upsala, where there is a spreading node, their breadth runs to 200 or 250 yards. From these facts the cubical contents of the asar may be guessed. They are often somewhat wider and higher at their northern end, that is, at their inception, than further on. In the low flat country their contour is very uniform, but in the upper and more hilly districts, where they chiefly abound, they have a tendency to become broken up into strings of separate mounds and kame-like masses. Their materials, 200 Sir A. H. Howorth—Surface Geology of N. Europe. in so far as they consist of boulders, have in every case where they have travelled, and we can trace the mother rock in sit#, moved from north to south, and were never in the reverse direction. One of their most important features, and one which has been a great deal too little noticed in the various theories which have been forthcoming to explain them, is the fact that they traverse the country quite irrespective of its contour, going uphill and downhill, and athwart the natural drainage. On this point I will quote the language of a first-rate authority, Erdmann. After saying that they sometimes run along the valleys, sometimes on the mountain flanks, and sometimes on the plateaux, he adds (in italics) the words : “C’est ainsi qu’elles continuent leur cours lointain, franchissant les plateaux, les vallées, et les plaines, et ne semblant en aucune maniére s'inquiéter des reliefs divers actuels du pays.” (‘Hxposé,” ete., p. 41.) This is a conclusion drawn from the Swedish asar. The Finnish ones are quite as remarkable, traversing lakes and watersheds without any hesitation. As I have said, a large portion of the asar consist of masses of rounded stones of various sizes up to 2 feet in diameter. These rounded stones are not mixed with angular erratics. The latter, when they occur, do so in the upper and more sandy and loamy layers, or scattered over the dsar’s backs, nor, so far as I could observe, do they contain stones of exceptional size. These, again, chiefly occur in the sandy beds or on the backs of the asar. Their contents are not sorted according to their size, but the stones generally lie with their longer axes parallel to the direction of the as in which they are found. The beds of sand and the sandy asar are in nearly all cases more or less stratified. They are frequently false-bedded, and the beds which show the false-bedding have their lines very pronounced, the angular wedges of sand and the lenticular masses being on a large scale and very marked. The uppermost layers of the asar often consist of stiff blue clay or of finely sifted and laminated brickearths, containing in places numbers of diatoms and marine shells, but never, so far as I know, fresh-water débris or land molluscs. These beds of brickearth and clay occur only at the top of the &sar, where they are often intercalated with sand beds very irregularly disposed, just as they are in the beds of contorted drift in the Cromer cliffs, and they are generally continuous with the mantle of similar loam that covers the intervening country. I cannot follow Erdmann and Geikie in separating these superficial layers in the asar from the beds below. So far as I can judge (and here, again, the present condition of the cutting at Upsala is very pregnant with meaning), they pass continuously down into them, and are merely later phases of one deposit, just like the similar phases we see in the drift beds of Hast Anglia. Lyell, Murchison, and others, who examined the Asar with care and skill, and whose judgment was in this case unwarped by a priori theories of the origin of the asar, treated the superficial beds containing marine shells as belonging to the same period as the lower beds, which are barren and consist largely of boulders. Sir H. H. Howorth—Surface Geology of N. Europe. 201 Let us now consider the theories which have been adopted to explain the asar. In the very early days of the Glacial fever—if I may coin an incongruous but not inappropriate phrase—when Agassiz reigned supreme, they were pronounced to be moraines. This conclusion is one of those which form the despair of rational science, for beyond the fact that they are heaped-up mounds of earth and stones, there does not seem to be a single feature about them resembling moraines. The stones they contain are rounded, water- worn boulders, in no way like glacier stones. Scratched stones, or those with flat sides, are never found in them. The beds of sand and clay they contain are sifted out and separated from the boulders, and are stratified and absolutely different to the mixed-up hetero- geneous “muck” forming moraine stuff. The shells they contain in their upper layers are marine shells, many of them perfect and of very delicate texture. Marine shells and diatoms are not the product of ice-sheets or of glaciers, and do not occur in moraines. Putting their contents aside, their other features are quite different to moraines. Terminal moraines, which are the only kind of moraines distinctly resembling some phases of the asar in contour, are always planted athwart the line of march of the ice. The asar, on the contrary, are all roughly parallel to the line in which the stones have moved, and to the line also kept by the stria on the rocks. If moraines at all, the &sar must therefore be medial or lateral moraines. Who has ever seen lateral or medial moraines made up of water-worn boulders and of stratified sands and brickearths con- taining marine shells, or seen them ranged in a large series of parallel mounds with subsidiary branches, and with no high lands in between from which their contents could be derived? But I need not press the argument further. Berzelius, in a letter to Professor Leonhard written as far back as 1841, says: ‘Agassiz’ friend Desor visited us in September last year, and on seeing the immense boulder deposits which in this country are named Asar, stated without hesitation that these phenomena could not be explained by glaciers, and that they were not moraines.” (Q.J.G.8., iii, 76.) Durocher also long ago analyzed the various features of the asar in a masterly manner, comparing them point by point with moraines and their structure, and showed how completely they differed from them. Reclus, who, although not a professed geologist, has treated geological problems with great intelligence in his great geographical work, is not less emphatic in his conclusion. Murchison and Verneuil and other “ old masters ” who examined the problem on the ground were of the same opinion. Nor do I know of any Scandi- navian geologist who now maintains the view that the asar are moraines. If there be any geologists that do so anywhere, it must be in America, where the most extravagant school of glacialists survives, and where official geology is so dominant, and every officer of the Survey is apparently so dragooned by the conditions of the service, that they follow their bellwethers with commendable loyalty and discipline. . P02) stipe Jal, Jel, ov orth Sangitce Geology of N. Europe. If not moraines, what are the asar? Hisinger suggested that they might be the remains of a gigantic denudation, the intervening deposits having been swept away. This view, while it did not in any way explain the internal structure of the asar, merely pro- fessed to explain their external shape and distribution. It has been completely analyzed by Térnebohm, and shown to be quite untenable; nor do I know anyone who now holds it, or who in fact professes to understand how such a denudation could come about. What kind of diurnal or other denuding agency would permit of these ramparts of soft materials remaining as they are when the rest of the beds were swept out? Whence could it come? How could it work so as to move up and down the country irrespective of its contour? Where has the débris of the gigantic denuding process gone to? How is it that the covering of the asar, which is formed of finely levigated brickearths, is also the covering of the intervening plains on either side? But I will not argue against a cause which has no defenders, nor kill again the corpses which Térnebohm slew. Every Scandinavian geologist known to me now admits that the asar are in some way the result of aqueous action. The contour of their surface, the rounding and arrangement of the boulders in them, with their longer axes symmetrically placed parallel to the — lines of the ramparts, the stratified sands and laminated clays, the current bedding, the presence of shells and diatoms, are all con- clusive that the asar are the result of aqueous action in some form or other; and Mr. James Geikie himself, who represents the high- water level of English and Scotch glacialism, says “all geologists admit that the asar are in the main water-formed accumulations.” Erdmann, Térnebohm, Nathorst, and all the other Northern geologists known to me, are of the same opinion. When we come, however, to discuss the particular kind of aqueous agency to which the asar may be assigned, and the method in which it worked, the unanimity at once ceases. The superficial resemblance of the asar, when drawn on a sheet of paper, to rivers with a main trunk and branching off into smaller affluents, perhaps first suggested the idea that they had something to do with rivers and river action; a view which has prevailed very considerably in textbooks, but which seems to me to be absolutely untenable. Two theories of the fluviatile origin of the asar have been pro- pounded, one treating them as the result of subaerial rivers and the other as subglacial streams. I would first criticize the general theory of fluviatile origin. : In the first place, as we have seen, the asar do not run along level surfaces nor along continuous slopes; but they frequently run up and down hill. Sometimes they are found — at a height of 2,000 feet and sometimes only a few feet above the sea-level, and they run up and down the undulating country keeping the same general direction. Now whatever movements are possible with ice under certain conditions, by which it may ° Sir H. H. Howorth—Surface Geology of N. Europe. 203 be able to move up and down slightly undulating districts, and sometimes to creep uphill to a moderate extent, it would be an entirely new and surprising fact that water could do so, unless contained in a pipe and forced up by pressure behind. This is an initial difficulty of the first moment, and is in fact absolutely conclusive. Water, except in a pipe, cannot move contrary to gravity, cannot travel up and down hill, or mount a slope; and it does not matter whether the water is in a channel open to the sky, or in a channel covered with an arched tunnel of ice. It is therefore impossible on this ground alone that the asar could have been deposited by rivers of any kind, unless the contour of the country has entirely and radically changed since they were laid down. . This is by no means the only. objection to the fluviatile theory of the asar. Their shape, when viewed in section, is quite opposed to a fluviatile origin. Rivers which run very slowly and carry much mud, instead of depositing that mud entirely in deltas, sometimes, no doubt, raise their own beds, like the lower Rhine and some rivers of Eastern England do, and in this way make themselves solid aqueducts along which they flow. These solid aqueducts, however, have not the shape or contour of asar, with their often steep and sharply inclined sides. ‘This contrast in contour is even more marked in the heaps of débris which form the beds of subglacial streams. Nor can I see how rivers of any kind could raise their beds to the portentous height of the asar and yet be so narrow. Rivers, again, must have banks, and if of fluviatile origin the asar should form channels running along their crests. The solid aqueducts we have experience of elsewhere are none of them very high, but are always breached and broken through after a time, when the river escapes and forms itself another channel, leaving the old bed meandering like a gigantic snake in the valley bottom. We cannot conceive such solid aqueducts remaining intact until they have been raised to a height of 300 or 400 feet. Another difficulty presents itself when we compare the contents of the asar with those of such river-channels as we can examine. Rivers which elevate their beds by gradual deposits are necessarily sluggish and slow-flowing rivers. When rapid, rivers become scouring agencies and not depositing ones. How is it possible to conceive of a sluggish river depositing these enormous masses of cannon-shot gravel — not of laying down a few yards of such gravel when there is an occasional rush in the stream, but a rampart a hundred miles in length and fifty yards high? The position is incredible. The Nile, the Rhine, the Indus, the Amazon, all these deposit beds, but they are beds of finely sifted mud. Again, in depositing stones, rapid rivers sift them according to their specific gravity, and do not mingle them higgledy-piggledy as they are mingled here. If it was a river that deposited these mountains of boulders, it must have been a very violent torrential river, and its force quite portentous along its whole course. If so, how is 204 Sir H. H. Howorth—Surface Geology of N. Europe. it that it did not scour and move away all the sand and brickearth, and carry them down to its lower reaches, instead of laying them down along their whole course? All torrential rivers known to me have clean-washed, stony, and gravelly beds, with deltas or reaches lower down, formed of the lighter materials of denudation. But in bespeaking torrential rivers of this kind in Sweden we are postulating a virtual impossibility. The level of Sweden is'too low and too flat to afford such rivers. To get rapid rivers we must have steep slopes in their beds. Of course we have a rapid flow enough at places like Trollhattan, on the Gota river, and in other gorges where we have rapids like we have in the gorges of the Rhine; but there is no deposit like an asar deposit in these gorges now. We cannot conceive any deposit of any kind long remaining in such places, nor does it seem possible that these gorges existed when the asar were made. Elsewhere than at these gorges the rivers of Sweden are quiet and slow-moving, and deposit, not great masses of huge boulders, but sand and silt and mud. They must have been slower and less efficient as dynamical instruments when the level of the country was much lower, as apparently was the case in Sweden in so-called Glacial times. Again, the rivers of Sweden naturally flow from west to east, or N.W. to S.E., in channels in which they drain the upper plateau by running downhill to the sea, - while, as we have said, the asar run from north to south, right across the present river-channels and right across the lines of drainage of the country. Again, rivers make deltas. When they have run their course, and get on to fairly level ground, they deposit fan-like stretches of mud and clay. There are no similar phenomena in the case of the asar, which do not terminate as deltas at all, the flat spreads of gravel sometimes occurring in connection with them being torrential, and not like river deltas. Rivers naturally have wider and wider channels as we move away from their sources to their mouths, and as their supply of water increases from their several feeders, and consequently as their loads of débris increase. ‘This means that their beds become wider and deeper as we proceed downwards along their course. They are thus quite different to the more or less uniform ramparts called asar, which chiefly differ in bulk in the fact that they are bigger at their initial stage than later on. It seems absolutely impossible to correlate the asar of Dalecarlia and those of Finland, some of which actually cross one another, and others are united by cross pieces, with any river-beds, whether subaerial or subglacial. Again, rivers of any size generally contain — fresh-water shells or other débris. The asar, on the contrary, when they contain shells at all, contain marine shells only. Rivers do not deposit marine shells. Lastly, we must not forget that although we are considering the © asar as substantive phenomena apart altogether from other deposits, it is only for convenience of treatment. We cannot, in fact, separate the asar and their contents from the sporadic and other deposits of Sir H. H. Howorth—Surface Geology of N. Europe. 205 the same kind occurring elsewhere. The asar are only heaped-up ramparts of materials which occur in the areas lying between them in a less prominent fashion, in some cases as scattered boulders, in others as continuous beds of sand and gravel and_ brickearth. Hspecially is this so with the brickearth or loam which often forms their upper layers. This is really part of the continuous mantle of the country. Such different deposits oceur virtually at all levels. How is river action to account for these complementary phenomena ? Rivers cannot spread over a whole country so vast as Sweden. They would cease to be rivers, and would become quite transcendental, like Baron Munchausen’s dreams, and if. they did so they would interfere with each other’s beds, and the ramparts would have been levelled down. It is clear that in finding an efficient cause for the asar we must find one which will also explain the deposit of the drift occurring outside them. Apart from and altogether beyond these difficulties is the supreme meteorological objection as to whence the rainfall was to come to fill these stupendous rivers, running parallel to one another, quite near together, and forming such a web of rivers as was never seen elsewhere. Where is the gathering- ground and where are the watersheds which could produce such a congeries of rivers? This is an important matter to those among us who believe in inductive methods in science. It is apparently of no consequence to those geological alchemists who are continually engaged in extracting palm-oil out of paving-stones. We cannot understand any meteorological or physical change which could supply the necessary rainfall for such rivers. On every possible ground, therefore, known to me it seems quite impossible to connect the asar with river action. This is not my view only; it was the view of my master, Murchison, also. He says: “However it may be argued that in mountainous tracts torrential rivers and their feeders may have descended as they do now, and may thus have produced rounded materials in valleys, the argument is, at all events, perfectly inapplicable to the formation of the Swedish asar. These linear ridges have not only been accumulated in long trainées and lengthened mounds on terraces high above the valleys, but offer appearances entirely unlike those produced by rivers.” This view is, in fact, also endorsed by Professor James Geikie - in regard to subaerial rivers. He says: ‘Banks of gravel and - sand no doubt accumulate in the beds of rivers, but if the rivers: were to disappear such banks would not form prominent ridges rising abruptly above the general level of the surrounding land. They would, moreover, coincide throughout any course with the lowest level of the valley, but our asar, although they trend with the general inclination of the land, do not slavishly follow the line of lowest level, showing an independence of the minor features of the ground, sometimes winding along one side of a valley and sometimes along the other.” (‘‘ Great Ice Age,” p. 169.) While Professor Geikie rejects Tornebohm’s theory of the asar having been the result of the action of subaerial rivers, he is willing 206 we. i, Cowper Reed—On the Cheiruride. to accept the notion of D. Hummel and P. W. Strand that they may have resulted from the action of subglacial streams, and apparently also favours that of Dr. Holst, who assigns them to streams flowing over the surface of the ice. Now in regard to these theories, it seems to be forgotten by every glacial geologist that a subglacial river or a river flowing on the surface of a glacier differs from other rivers merely in that it flows under a long tunnel or archway of ice, or over a bed of ice instead of a bed of sand or gravel. In every other respect it is a river, and every difficulty which has been already pointed out in regard to the explanation of the asar by river action of any kind is as potent and conclusive against these postulated glacial or glacier rivers as it is against ordinary rivers. In addition they present special difficulties of their own. Let us first look at the theory of Holst. It is quite true that when the sun beats upon the back of a glacier small streams are sometimes seen on its, melting surface, which run for a few yards and then disappear down a crack or a crevasse. Nowhere, not even on the vast ice-plains of Greenland, do these small streams now grow into rivers; and in order to do so we must suppose that the ice was marked by no cracks or crevasses, and in the particular case of Scandinavia that in a singularly broken and uneven country an ice-mantle could exist without any crevasses or cracks draining its surface. But suppose it could, whence could it derive the materials for making gravel, or the great boulders, when the whole country was, ex hypothesi, blanketed with ice, and no exposed rocks were visible? And having got hold of rocky débris, how were these supraglacial streams: to roll the millions of great boulders of granite, gneiss, and basalt, which form so large a part of the asar, into their rounded and water-worn shapes, and accumulate them in dykes and embankments a hundred miles long and a hundred yards high ? and how is it that the rest of the glacier’s back or some part of it was not uniformly strewn with angular and unrolled, or with rolled débris, which should have remained when the glacier melted alongside of the asar? Assuredly the whole idea is incredible, and it is incredible how sober, thoughtful men in our century should have tried to impose it upon science. (Lo be continued in owr next Number.) II].—Notes on THE AFFINITIES OF THE GENERA OF THE CHEIRURIDA. By F. R. Cowrrtr Resp, M.A., F.G.S. N a former number? of this Magazine the evolution of the sub- genera of the single genus Cheirurus has been discussed, and ~ it is now proposed to examine the mutual relations of the other genera of the Cheiruride. Some diversity of opinion has existed as to the genera which may be grouped together to form this family. Barrande? put only the following five genera into it: Cheirurus, Spherexochus, Placoparia, Staurocephalus, and Deiphon. 1 Reed, Grou. Mae., Dec. IV, Vol. III (1896), pp. 117 and 161. a Barrande, Syst. Sil. Bon os vol. i (1852), pp. 835 and 766. F. R. Cowper Reed—On the Cheiruride. 207 The last-mentioned genus was only provisionally united with the others. Salter,! while omitting Placoparia from the above list, added Amphion, which Barrande placed in the family containing Encrinurus, etc. The genus or subgenus Spherocoryphe was also really included by Salter, but under the name of Staurocephalus ? unicus. The genera Encrinurus, Cybele, and Zethus were also given by Salter as belonging to the Cheiruride, but with a query against each of them. Zittel? places the following genera in this family: Cheirurus (with its subgenera, Cheirurus, s.s., Cyrto- metopus, Spherocoryphe, Crotalocephalus, Eccoptocheile, Pseudospher- exochus, and Nieszkowskia), Areia, Deiphow, Onychopyge, Placoparia, Spherexochus, ? Crotalurus, Staurocephalus, Amphion, Diaphanometopus. Of these, Crotalurus must certainly be at once removed to another family and group, because of the course of its facial suture.’ More recently, Beecher,* in a valuable and suggestive paper on the classification of trilobites, has enumerated the genera and subgenera in this family thus: Cheirurus, Actinopeltis, Amphion, Anacheirurus, Ceraurus, Crotalocephalus, Cyrtometopus, Deiphon, Diaphanometopus, Eccoptocheile, Hemispherocoryphe, Nieszkowskia, Onychopyge, Pseudospherexochus, Spherexochus, Spherocoryphe, Stauro- cephalus, Youngia. Eliminating the subgenera we get the following: Cheirurus, Amphion, Deiphon, Diaphanometopus, Onychopyge, Spher- exochus, Spheerocoryphe, Staurocephalus, and Youngia. Spherocoryphe must, in my opinion, be accorded generic rank. The genera Placoparia and Areia are placed by Beecher in the HEncrinuride on account of their larval features, which suggest their union with this more primitive and less specialized family. In fact, he would apparently regard these two genera as morphologically the lowest in the phylogenetic list of the members of his order Proparia, which com- prises the four families Encrinuride, Calymenidz, Cheiruridz, and Phacopidee. Omitting the imperfectly known and extra- European genus Onychopyge, we may concentrate our attention on the other genera which have been accorded a place in the Cheiruridee, and all of which are found in Europe. The four genera Placoparia, Areia, Amphion, and Diaphanometopus are those whose true position is most a matter of doubt. Schmidt,® for instance, hesitates somewhat in retaining the two last genera in the Cheiruride; and the different views of Salter, Barrande, Zittel, and Beecher with regard to Amphion and the others have been mentioned above. The question can only be decided by the characters which one considers as essential to the family. But it is a matter of minor importance how we group together the genera in a system of classification, so long as we understand their phylogenetic relations. In Areia, in the first 1 Salter, Mon. Brit. Trilob. Paleont. Soc. (1864), p. 2. 2 Handbuch der Palaontologie (1885), vol. ii, p. 616. 3 In Zittel’s ‘‘ Grundziige der Palaiontologie ’’ (1895), this genus is omitted from the Cheiruridee. 4 Amer. Journ. Sci., vol. iii (1897), p. 89. > Mem. Acad. Imp. Sci. St. Petersb., vol. xxx, No. 1 (1881): Rey. ostbalt. Tril., Abth. i, pp. 190, 195. 208 Este Cowper Reed—On the Cheiruride. place, the absence of facial sutures separates it from all the other genera in the Cheiruride, while this feature, combined with the absence of eyes, the pentamerous lobation of the head, the expanded termination of the glabella, and the presence of the pleural row of puncta on the neck segment (in A. Bohemica), and the close resemblance of this segment to the thoracic segments are larval features which indicate a very low stage of development and a comparatively small amount of differentiation. The Bohemian species of the subgenus “ecoptocheile resemble it in the row of puncta on the inner portion of the pleura, the number of the thoracic pleuree, and the notch on each side of the glabella in the front border of the cephalon; and Barrande himself remarks that Barrande, Syst. Sil. Boh. ae i, Suppl., p. 118, pl. ix, fig. 3. 3 Tbid., p. 119, pl. vii, figs. 5, as F. R. Cowper Reed—On the Cheiruride. 211 and it can easily be derived from that of a typical Cheirurus by a broadening and flattening of its several parts. Turning now to another branch of the family, we find in Spherocoryphe the forerunner and ally of the peculiar genus Deiphon. ‘The relations of Spherocoryphe to Cyrtometopus have previously’ been discussed. Some of its leading characteristics we find repeated but more accentuated in Deiphon. Thus, in Spherocoryphe the enormously inflated anterior portion of the glabella and the faintness of the first and second side-furrows foreshadow the condition found existing in Deiphon, in which the two pairs of furrows have disappeared and the glabella has a regular globular form. In several species of Spherocoryphe (as, for instance, Sph. Hubneri and Sph. unicus) the basal lobes of the glabella are distinct, but in Sph. cranium they are very faint, and thus prepare us for their complete absence in Deiphon. Again, in Spherocoryphe the free cheeks are merely small triangular plates, bearing the eyes, wedged in on the anterior border of the fixed cheeks; in Deiphon the reduction in size of the free cheeks has proceeded so far that they are only represented by the eyes and a small part of the doublure of the head-shield. The fixed cheeks in Spherocoryphe bear one or more tooth-like processes on their front edge; in Deiphon the fixed cheeks are so narrowed and modified as to form long spines, but they still bear the tooth-like process on their front edge, as in Sph. granulatus. In the thorax we find on the pleura in Spherocoryphe a longitudinal furrow, and in the Bohemian individuals of Deiphon Forbesi there is also a similar, though fainter, furrow present.” The reduction in the number of the body-segments to nine is certainly in this genus, as in Sphereaochus, a sign of high specialization when we consider it in conjunction with its other characters, but the loose build of the body and absence of fulcrum seem to be reversions to the more archaic types, and to represent the gerontic and degenerate stage in the phylogeny of the group. The migration of the eyes forwards to the anterior edge of the head-shield is also distinctly a retrogression to the larval con- dition, for it has been proved* that the eyes first appear on the anterior margin of the dorsal shield in the protaspis, and move backwards in subsequent stages of growth. The pygidium in Deiphon has only one pair of pleuree—the first pair; but this pair is enormously developed. The pleure of the other segments are aborted; but four segments are traceable on the axis. This great development of the first pair of pleure is likewise foreshadowed by Spherocoryphe, for in Sph. unicus the first pair is much enlarged, while the posterior ones are reduced. There seems 1 Grou. Mae., Dec. 1V, Vol. III (1896), p. 118. * Salter says (Mon. Brit. Trilob., p. 88) that the pleure are ungrooyed, but in his figures of the species (ibid., pl. vii, figs. 1-12) furrows are shown. Barrande both describes and figures the furrows (Syst. Sil. Boh., vol. i, Suppl., p. 115, pl. ii, figs. 19, 20). Perhaps, as Barrande suggests, for this and other reasons the Bohemian and English species are not identical. 3 Beecher, Amer. Geol., vol. xvi (1895), p. 177, and references. 212 Jaap Cowper Reed—On the Cheiruride. to be a frequent tendency in the Cheiruridee for the posterior pairs of pleuree to be reduced, and we find it remarkably exhibited in Meszkowskia. In regard to Deiphon, though the morphological value of its various characteristics may be a matter of dispute, yet its high degree of specialization must be generally acknowledged, and we would place it at the end of this branch of the family. Beecher’ has also briefly stated that he is of this opinion, and he associates with it the Australian genus Onychopyge. Turning now to the aberrant and imperfectly known form Youngia, distinguished by Lindstrém? as a separate genus, we find there are only three species established, and of these only the head-shields have been discovered. One of them (Y. érispinosus) is found in the Penkill mudstones of the Girvan district. The characters of its head-shield link it on the one hand with Pseudospherexochus, and on the other with Spherexochus. The spiniform fixed cheeks recall Deiphon, but their development is not so extreme; the neck spine is a marked feature, but does not seem to be of phylogenetic importance. In some species of Acidaspis and Lichas a spine is developed in the same place, while other closely allied species are destitute of this ornament. Bernard* has compared this organ, which is often a mere tubercle, with the dorsal organ of Apus, and suggests that it was poisonous. Lastly, the genus Staurecephalus demands our attention. This genus, though frequently stated to be allied to Spherocoryphe on the strength of its abnormal glabella, possesses in reality many important dis- tinctive features. The hypertrophy of a portion of the glabella has in my opinion more of a physiological than of a morphological value. In the style and extent of the inflation of the glabella of these two genera a considerable difference is found to exist on careful examination. In Staurocephalus it is only the frontal lobe which is inflated and projects so conspicuously over the front border of the head-shield; the first side-furrows are very strong, and unite across the glabella in a continuous groove, thus sharply marking off the globular frontal lobe. The hinder portion of the glabella is parallel- sided, and has two pairs of furrows marking off the lobes distinctly, but the basal lobe is not circumscribed. In Spherocoryphe excessive development is shown by the glabella as a whole, with the exception of the basal lobes, which are in the form of nodules. The facial suture in Stawrocephalus cuts the outer border of the head-shield posteriorly, so that the free cheeks are of a fair size, but in Spherocoryphe the free cheeks are relatively very much smaller and of a different shape, owing to the forward course of the posterior branch of its facial suture. In fact, the two branches of the facial | suture in Spherocoryphe meet at a very acute angle, while in Staurocephalus they meet at almost a right angle. This feature, from what we now know of the ontogenetic and phylogenetic history 1 Amer. Journ. Sci., vol. iii (1897), p. 201. ® Ofver. Kongl. Vet. Akad. Forhandl., 1885, No. 6, pp. 49-61, T. xii, figs. 11, 12. 3 Bernard, Q.J.G.S., vol. u (1894), pp. 422-4. F. R. Cowper Reed—On the Cheiruride. 213 of the free cheeks, must be taken as of considerable importance. The marginal spines on the head-shield of Stawrocephalus Murchisont may perhaps be regarded as merely the multiplication of the one or two ‘pairs present in Spherocoryphe, but a marginal fringe of spines is of but little morphological value, for we find it in the most widely separated forms, such as Areia and Acidaspis, as well as in closely allied species. The cheeks of Staurocephalus are not pitted like most of the Cheiruridz, but are tuberculated, and in this respect, as well as in the stalked eyes, resemble some of the Encrinuride. But surface ornaments may have too much importance attached to them, and I doubt if they are often of more-than specific value. The thoracic segments show a considerable resemblance to those of some genera of the Encrinuridz in their shape, their rounded and ridged surface, and the fulcrum, beyond which they are sharply bent down. These features are suggestive, and seem to be of considerable value in this case in indicating the relationship of this strange genus. A furrow exists on the anterior edge of the pleure of St. Murchison, as Salter described, and a similar one occurs in the same position in Enerinurus. This furrow may perhaps not be homologous with the. ordinary diagonal or longitudinal pleural furrow of Bilton genera, but it is a common feature in Hucrinurus and Staurocephalus which is worthy of notice. In Spherocoryphe the thoracic pleure are not ridged, and the furrow which is present on them runs along the central line. However, we are not precluded from supposing the possibility of its obliteration when we recall the case of Spherexochus and Pseudospherexochus. In the pygidium of Staurocephalus we see again the impracticability of deciding affinities by this member. The pygidium of one species (St. globiceps) shows a close re- semblance to that of Spherocoryphe unicus, and in each form the first pair of pleuree is much enlarged at the expense of the others. But the less specialized pygidium of Sé. Murchisoni is completely different, and while retaining the Cheirurid character of a small number of segments, yet in its general shape, and the form and course of the pleure, it strikingly reminds us of some species of Amphion, and, more remotely, of some species of Cybele and Encrinurus. Barrande has remarked that its pygidium shows a particular analogy to that of Ch. twmescens. From the foregoing consideration of some points in the anatomy of Staurocephalus I am led to conclude that its affinities are rather with the Encrinuride than with the Cheiruride, and that its resemblance to Spherocoryphe is more superficial than real, and is probably an instance of iso- morphism. The pygidium in any genus is too variable a feature to be of much use in determining true relationships, but in the simplest and least modified form of this member, as represented in St. Murchisoni, it is deserving of notice that there are indica- tions of an alliance with the Encrinuride. It may here be remarked that in the latter family the large number of segments on the axis of the pygidium probably does not represent so large a number of coalesced pygidial segments, but is due to the secondary sub- division of the original segments. Finally, we must come to the 214 Rev. J. F. Blake—The Llanberis Unconformity. conclusion that Stawrocephalus diverged from some early Encrinurid, and while retaining several of its ancestral characteristics underwent a development under somewhat similar conditions as Spherocoryphe, leading to similar adaptive changes in certain points of its structure. 1V.—A Revinprcation or THE Luanserts Unconrormiry. By the Rev. J. F. Buaxz, M.A., F.G.8.! (Concluded from the April Number, p. 178.) The District South-West of Llyn Padarn. HIS is undoubtedly the most difficult district to deal with, and one in which I have had to change my views on certain details. Still, there is one part of it where the evidence is very clear, namely, the ground between the railway and the road at the’ Tan-y-pant inlet. This was apparently not examined by Professor Bonney when he visited the locality, and its teaching is evidently not appreciated by his coadjutor. They say that the section at what they call “the supposed junction” is undoubtedly very difficult. One thing, however, is clear, since we all agree about it. The junction of a rock of felsitic character with one like a purple slate is vertical. There are here only two alternatives: either the felsite is intrusive into the purple slate, as the junction at first sight certainly suggests, or the purple rock was deposited on the felsitic one. In spite of appearances, we agree to reject the former alternative; but my critics seem to think they are correcting me when they agree with me in accepting the latter. The only possible difference between us is, that what I called felsite, including therein, as I remarked in a note, “felsitic ash,” they call ‘“felsitic grit.” This difference, which, as far as I am concerned, is merely one of words, is quite irrelevant to the argument that the junction-line between two deposits must have been at first approximately horizontal, and have been subsequently turned on end. But the neighbouring conglomerate lies in a hollow on the present upper surface of the felsite, and must therefore have been deposited after the rocks had been turned on end, and therefore be of later date than the slate. (See Fig. 1.) I, IN nF 7 Wests PET Frc. 1.—Relations of slate (1), felsite and associates (2), and conglomerate (3) at the inlet by Tan-y-pant, Llanberis. It is true that my critics draw a fault somewhere about here, — but it is not clear where they think it runs. It cannot be in the slate, as that would throw no light on the question ; it cannot be at | The substance of a paper read to the Geological Society on December 1st, 1897, with additional remarks. Rev. J. F. Blake—The Lianberis Unconformity. 215 the junction, which they describe as a surface of original deposit : it must be in the felsitic part, probably at some supposed junction of felsitic grit with true felsite. Such a fault would have to rotate the conglomerate and bring it out from between the felsitic grit and felsite. Now, the rocks in this area are quite bare, and one can see for certain that there is no fault; even the mass that discloses the junction with the slate is continuous till it becomes a true felsite. The only possible fault in the neighbourhood is on the other side of the mass of purple slate between it and the next exposure of conglomerate, that is, along the face of the cliff above and below the road. The similar section described by Sir A. Geikie (H, p. 96) is doubtless on the continuation of the line of junction seen below. The purple slate? is there also said to be nearly vertically inter- banded with felsitic material which passes towards the west into a true felsite. Sir A. Geikie does not say exactly where this section is, but describes it as separated from “the porphyry of the ridge” by a “zone of conglomerate and grit,” so it is most likely where Miss Raisin has inserted felsite on her map. In my map, however, it is included with the ‘“ Post-Llanberis,” because on the upper surface there are scattered here and there some pebbles of quartz, so that it is covered, as it were, by a skin of conglomerate. Here again, then, if the spot is rightly identified, the plane of junction with the slates is nearly vertical, while that with the conglomerate is horizontal.® This inlet section is really an important one, as it is the only place I know of, except in tunnels, where the felsite and any other rock than the conglomerate can be seen in unbroken sequence. What we see in such a case I regard as one irresistible argument for the unconformity I postulate, and, so long as it holds, the question whether the purple slate here is the workable slate or not is of secondary importance, for if the conglomerate is unconformable it may just as well extend over the workable slate as not. The rock is like the workable slate, and like no rock out of that group; as a fine-grained rock it cannot be a mere local deposit; and it 1s in continuation with the worked slate which runs over the hill to the south-west. My critics also recognize in it one of the characteristics of parts of the workable slate series—the “interbanding of fine grit and purple slate,” which is quite a distinct thing from the “alter- nation of hard grey slate, transversely cleaved, and coarse grit,” characteristic of the Post-Llanberis group. 1 Professor Bonney and Miss Raisin also claim a fault on the other side of the conglomerate, between it and the main mass of the felsite, but the junction may be seen in a block near the water’s edge; one is welded to the other. 2 So gradual is the passage from one rock to the other that Sir A. Geikie considers the parts of the slate nearest to the felsite to be only a cleaved portion of the latter. 8 A similar argument is applicable to the tramway section on the opposite side of the lake. The felsite there shown next the first conglomerate is followed beyond the conglomerate (and a dyke) by nearly vertical slaty beds, but the summit of the felsite crag shows a covering of conglomerate, indicated by the presence of quartz pebbles. Here, however, the vertical succession is broken. 216 Rev. J. F. Blake—The Llanberis Unconformity. Next, they cannot believe that the conglomerate passes over to the other side of the purple slate, because the rock there found seems to them to be less squeezed, more purple, with a few additional varieties of pebbles, and thinner. These differences (excluding the first, which one cannot deal with seriously) are slight at the best, and just what we should expect in a shore deposit, the change in colour being related to its position over purple slate rather than over felsite. Next, in relation to the synelinal in the railway cutting and my belief in its unconformity, Miss Raisin says that the purple slate ‘“‘turns up again” on the south-east side of it, and thus behaves as the overlying strata do. But the phrase quoted is ambiguous; it may be intended as a colloquial expression for “occurs,” or it may mean that the dip is changed. It is quite to be expected that slate would occur where she has marked it, and, indeed, I have it so in my note- book section, here copied (Fig. 2), though it is omitted in my general section of this cutting, but I could find no proof of dip in it, while in the nearest visible purple slate I noted a high dip to the E.8.E. as on the other side of the synclinal. But an unconformity or its W.S.W ris ek Fie. 2.—South-east end of the synclinal in the Llanberis railway cutting. (1) Purple slate, (2) green (St. Ann’s ?) grit, (3) greenstone, (4) conglomerate, (5) grit. absence cannot be proved in this sort of section; it is too obscure. Its only use is to show how far an unconformity, otherwise proved, extends over the underlying rocks. Still, what we see here is more favourable to an unconformity than the reverse. I pointed out that the conglomerate “ mounts up over the back of the greenstone boss ” and passes to the other side, as now shown in Fig. 2. This looks like a transgression over the outcrop of slate.’ IT also described the conglomerate as leaving the felsite along the north-west boundary and disclosing between them a different succession. I briefly described the immediate successor of the felsite here as a hard purple slate, but Miss Raisin goes into details and records between the felsite and conglomerate a breccia, a pebbly grit, a banded grit and argillite (a greenstone), and a purple grit,— just what we might expect to follow the felsite in spots now further west, representing hollows on its surface at the time of their deposit. 1 The following quotation from Professor Bonney’s paper (C) will show that he at that time gave quite a different account of this section from mine and Miss — Raisin’s, and considered the conglomerates now distinguished as inseparable except — as varieties. ‘‘ The cutting : passes into fine green grits or ‘bastard slate,” beyond which we find a thick mass of interbedded conglomerate and similar grit, then another band of grit, followed by a band of small rolled fragments of felsite about as large as hemp-seed.’’ It is plain that either what he here calls fine green grit or bastard slate is the same as that now called purple argillite, or he has missed the first conglomerate in the cutting, and takes the next band to be the ‘‘ Cambrian”? conglomerate, calling it ‘the finer variety,’’ and saying that ‘‘ with cousiderable variety of detail the general character of these is similar.’’ Rev. J. F. Blake—The Lianberis Unconformity. 217 Their occurrence indicates a long interval between the outflow of the felsite and the deposit of the conglomerate, and this interval must include an unconformity, since the conglomerate comes back again and lies on the felsite in a very short distance. My critics try to account for these numerous intervening beds, each indicating some change of conditions on the same spot, by reminding us of the interchangeable deposits of grit and coarser material on the seashore. This I have already allowed for, having included with the con- glomerate much that is only the red grit into which it passes in places. . In connection with the strata which overlie this conglomerate, I am charged by my critics with inaccuracy when I say, speaking of their lamination, that almost wherever seen these laminz are horizontal. No doubt from its form this statement is lable to be taken to mean that the strata are almost always hori- zontal. That this is not the meaning might be inferred from the high dips shown in my section of the railway synclinal, which must necessarily be continued into the country behind. They are, in fact, seen, as stated by Miss Raisin, in many places. But the question is whether in places where the dips are high the lamina can be seen. Possibly they can; I have, however, seldom found them, except where the strata are nearly horizontal, either in this district or higher up on the hill, or on Y Bigl, and even Miss Raisin only speaks here of high dipping “outcrops,” but when elsewhere “lamination” is mentioned it is accompanied by the word “horizontal” (loc. cit. (K), p. 588). These horizontal laminze are for the most part only observable on the summits of elevations, such as the spots I named (10, 16, 18, on my map), the last one being both the highest and best; it is marked 666 on the 6 inch ordnance map. How such horizontal lamines above are compatible with highly inclined outcrops below, is explained by the deposit of the strata on an undulating surface. Those lying in the hollows would be squeezed*into synclinals under earth pressures, being nipped in between the older and harder rocks, while the higher ones might escape.' Thus the high dipping outcrops in the low ground are no arguments against the general horizontality of the strata, and therefore call for little notice. If Miss Raisin had given the direction of the dips she noticed we might find that their average was zero. I ought to remark, however, that my words “dip” and “horizontal” here have reference to the apparent dip in a direction parallel to the lake-shore. There may be also, and probably is, more or less of a dip towards the lake in the direction of the strike of the underlying slates. We now pass to the strictures on my statement about the grounds of Glyn Padarn. They say it is not easy to recognize my “ definite succession along an H.N.E. and W.S.W. line.” Miss Raisin, however, has succeeded in doing it and in confirming my statement. But in quoting me my critics have omitted the words which I actually 1 The manner of this was illustrated by a model at the reading of my paper. 218 Rev. J. F. Blake—The Llanberis Unconformity. italicized as containing the gist of the matter, that this line is the line of strike of the purple slates. Is it necessary to explain that if these surface beds are bands in the slate series, and we go along the line of strike, we must continue on the same bed, and not change again and again? ‘The definite succession is fatal to the hypothesis. It indicates a strike at right angles to the dominant strike of the district, which is only possible in superficial deposits. Even a fault cannot do much towards altering the strike, unless it be on a geotectonic scale. j The dips Miss Raisin records in some part of these grounds are of no consequence from this point of view, though combined they give a general “gentle dip towards the H.N.E.,” and separately they indicate a slight synclinal arrangement. But in the centre of the grounds, standing with one’s back to the road and looking along the strike of the slates of the country as shown in the neighbouring quarry, we see the crag shown in Fig. 3. It illustrates at the same time the Fic. 3.—Low crag in the Glyn Padarn grounds, looking W.S.W. perpendicularity of the strike of the beds (whatever be their dip) to that of the slates, and my description of the alternations of trans- versely cleaved grey slate and coarse grit characteristic of the Post- Llanberis group. As noted above, a fault between this and the quarry would make little difference to the argument, but of such a fault there is absolutely no evidence, and in the absence of one the bottom beds of worked slate in the quarry, if continued on their rise, would run into this crag, or very near it. The transverse fault seen in the quarry has nothing to do with this, but lies beyond. In the large exposed surface of conglomerate “beyond the wall ” a band of purple slate most certainly lies with a very low dip upon Fic. 4.—Mass of purple slate mud, overlying conglomerate outside the Glyn Padarn grounds, looking N.E. it. This band is perhaps more probably a redeposited purple mud than a fragment. It is shown in Fig. 4. The conglomerate, pace Miss Raisin, does contain felsite pebbles, and in no way resembles the St. Ann’s grit, or any grit interbanded with purple slate Rev. J. F. Blake—The Llanberis Unconformity. 2g elsewhere, for, as desired by my critics, good “ distinctions between the various conglomerates and grits” have already been drawn, and in most cases, as here, can be easily recognized. I regard all this as very strong evidence that there are uncon- formable deposits here, and cannot see how it can be affected either for good or ill by anything that may be seen in the railway cutting. Nevertheless it is satisfactory to show how the neighbouring ex- posures can be explained in relation to our conclusions. Thus on the north-west side of the grounds we find purple slate and ordinary St. Ann’s grit coming on again at a higher surface-level. This I explain by the hypothesis of a fault which has let down the uncon- formable deposits to a lower level than they originally occupied. But to support this hypothesis we should be able to point out the fault and show that it lets down something—we cannot reasonably expect any particular kind of rock—on the §.E. side. Such a fault we can point to: see Fig. 5. This suggests at least, by the anticlinal { Fie. 5.—Fault seen in the Llanberis railway cutting, looking N.E. (1) Purple slate, (2) green slate, (3) slickensided fault, (4) conglomerate, (5) grit. structure on the left, that it is a down-throw on the right, and, as it happens, on this side are rocks, conglomerate and grit, which, from what we have observed above, could easily be brought here by a slight fault. In reference to this my critics say: ‘Mr. Blake speaks of it as a slight fault, but it is only so on his own hypothesis, and to argue from that statement is reasoning in a circle.” But I have not argued from it at all. If I were to do so now it would be to say that the hypothesis, that this conglomerate has been let down from above by a slight fault and forms the continuation of similar rocks near at hand, is a less wild one than that which supposes it to be “faulted up from great depths,’ and so have no relation to the neighbouring conglomerates. This last hypothesis is not even suggested by anything that is seen on the ground. Before leaving this district I should point out that the map of it given by my critics is inconsistent. They draw a fault by the Tan-y-pant inlet, and make the succession on the two sides of it different. On one side it is felsite, conglomerate, felsitic grit, grit with argillite; on the other, felsitic grit, purple slate, con- glomerate, grit with argillite. These two successions cannot both be the true one. The Tramway Section and Y Bigl. IT will not here, as I did at the reading of my paper, explain the corrections I have been led by additional observations to make in my own map, as they lead me further from my critics’ views, but will confine myself to their statements. 220 Rev. J. F. Blake—The Llanberis Unconformity. We will commence with the tramway section. Of this Professor Bonney gave a diagram in ©. He and Miss Raisin now give a second, and they say, “‘ we adhere to our original diagram.” If anyone will take the trouble to put these two diagrams (A and B) side by side and compare them, he will notice that (1) in A a fault is placed between the felsite and the conglomerate, in B it is shifted to the other side of the conglomerate; (2) in A purple slate is repre- sented as occurring in the synclinal, in B there is none; (3) in A the middle conglomerate is undivided, in B it is divided into two; (4) in A the beds between the second and third conglomerate are called green slaty grit, in B they are quite differently described ; (5) in A these beds are represented as forming an anticlinal, making the second and third conglomerates parts of the same bed, in B these beds are all made to dip towards the second conglomerate, making the third a distinct and lower bed. When, then, the authors claim that they adhere to the original diagram, and add, “ but would shift the anticlinal so as to fall nearly on the third conglomerate,” they might as well have said, “ but change it altogether.” I do not complain of a change of views, if frankly acknowledged, © but in this case I fear it is a change for the worse, for it lands them in many difficulties. The Cambrian conglomerate has gone by the board, and they have become quite lavish of their successive con- glomerates. They have already claimed one below that on the summit of Moel Tryfaen, and one above that next the felsite by the Llyn Padarn inlet, and here there must be a fourth unless they can account for the change of material lying between the supposed two on one side of the lake, and the two on the other. This material in one case is felsitic grit and purple slate, and in the other felsitic grit of a different kind and “rainspot breccia.” Next they have to account for the absence of the second conglomerate on the north-west side of the banded-slate synclinal, and to this end have to introduce a new hypothetical fault for which there is no independent evidence, but rather the reverse. Then they have to deny the identity of the very similar conglomerates in the two crags almost facing each other on the slopes of Y Big], on the sole ground that one of them contains additional varieties of pebble. At the same time they identify one of these, on the west of Moel Goronwy, with a totally different felsitic breccia, containing none of the great pebbles, on the east side. They have to make two conglomerates along the west side of that hill, where they acknowledge not to have examined the ground, and where there is certainly only one; and they draw the second con- glomerate in a straight band right over the high ground, thereby representing it as vertical, though in the tramway section they state that it has a moderate dip. There is, however, direct evidence that these second and third conglomerates are parts of one and the same sheet, for one can be traced round on the slopes above the section, passing across about the level of the lower road, with a very narrow interval of grass, into the other. This, while it negatives the new section, does not prove an unconformity; for if, as Professor Bonney originally Rev. J. F. Blake—The Lianberis Unconformity. 221 represented, there were an anticlinal here, the junction would naturally take place over its crest ; but of such an anticlinal no one, from Sir A. Ramsay onwards, has ever been able to find a trace, and it is now abandoned even by Professor Bonney and his coadjutor. From these considerations and others to follow I hold that an unconformity is the only alternative left, whatever may be the teaching of Professor Green’s section. This section, seen on the tramway, has been differently inter- preted by my critics and myself. If my opponents’ reading of it be correct, I should say with one of them that the unconformity was only locally absent; if mine be correct, it will afford only confirmatory evidence, valuable, no doubt, but not essential. My critics, however, try to give it an unmerited importance. They “are told,” they say, ‘‘ that here the hypothesis can be brought to a direct test.” They were certainly never told so by me. No hypothesis can become a conclusion without being subject to many tests, and a single section, with the possibility of a local absence of unconformity, is not suitable for a “ final appeal.” _ Yo me the evidence of this section is clear enough, but Sir A. Ramsay, Sir A. Geikie, and Miss Raisin are all against me, and I have only the support of Professor Green,’ a good stratigraphist. With regard to this support, it is not fair of my critics to say that ‘the only line which might be supposed, and has been supposed by Professor Green, to mark it [the unconformity] is not shown by Mr. Blake,” when I distinctly said that “his description is so wonderfully true to nature that I could only quote him verbatim,” including, of course, his diagrams. My general diagram was intended only to illustrate my view of the general relations, just as was Professor Bonney’s. I do not think the line which those who see conformity here have noticed some way down in the breccias is really a line of bedding. I can see there no change of material, but of course I may be wrong. But if so, there still remains the cleavage. Now cleavage, as Dr. Hicks pointed out, had already been produced in the district before the conglomerate, containing cleaved pebbles, was formed. Nor do I see how the angular fragments in the underlying breccia could have been turned round, thereby shortening the horizontal dimension of the rock, after the conglomerate was there, and yet leave an undulating, closely-welded line between the two rocks, seeing that the conglomerate has not been shortened, and the line of junction is, at least in places, perpendicular to the cleavage. Hence, whether from bedding or cleavage, I think the breccia fragments were made vertical before the deposit of the conglomerate. Again, my ‘critics say that “the ‘nearly horizontal line’ does not exist.” As to this, it must be remembered that for two rocks to be conformable they must be conformable everywhere, but to be unconformable they need only be unconformable anywhere. It is thus quite enough for the purpose that my critics themselves 1 Professor Hughes and Dr. Hicks accepted the unconformity, but I do not know that they have personally observed it. 222 Rev. J. F. Blake—The Llanberis Unconformity. draw a festoon on the boundary, part of which must of course be actually horizontal. It was, in fact, from this more horizontal portion of the boundary that I was judging when I wrote. But if the amount of dip be in question, none of the drawings yet given of the section are accurate enough. The two rocks are broken up by a number of transverse joints, along which slips appear to have taken place, producing a step-like series of festoons (see Fig. 6). If these were restored, the slope would not appear so great. (s} 002 2 Nina Lo, seaftit! sli aN ees a fe | | S71 Fre. 6.—Junction of conglomerate and breccia in the tramway cutting, Llyn Padarn, looking N.E. My critics further state that “the unconformity is quite dis- proved by the finer matrix graduating from one [the breccia] into — the other [the conglomerate ].” Tn a hand-specimen the line is sharp, and the two matrices are differently coloured. In the field the joint face of one is smooth, being along a cleavage plane; of the — other, rough, where the cleavage almost ceases. But a similarity of matrix is to be expected when one rock is derived from the other. This is perhaps the last district where such a similarity should be used as an argument, for here we have the well-known example of even a crystalline felsite yielding to the succeeding conglomerate a matrix which can be scarcely distinguished from the original rock. When the original is clastic we may well expect the derived matrix to be absolutely indistinguishable. The fallacy, too, of this argument has been already demonstrated. On this ground the conglomerate overlying the “ granitoidite” at Twt Hill was positively asserted to belong to the same series, but it was after- wards acknowledged to be of a totally different age and uncon- formable. J do not know that this section is worth all this labouring to prove its teachings. Iam only forced to it by the dogmatic tone adopted by my opponents. I should rather gather from the conflict of opinion here how very useless a single section may be to carry conviction as to the structure of a country; and in this case the further evidence enables us to dispense with it altogether. There is, indeed, in this district a discriminating test as to the truth of my reading or of that of my critics, which may be applied again and again in many places and in many ways. Immediately to — the north-west of Green’s section lies a synclinal of pale banded’ slates and grits, towards which, according to my opponents, the conglomerate is dipping, and which they take to overlie it. That is, Rev. J. F. Blake—The Lianberis Unconformity. 220 the slates are above the conglomerate. According to my reading, the conglomerate is unconformable over them. That is, the slates are below the conglomerate. Here, then, is a clear issue. As to this, my opponents state as “ further proof ” of their view, that “the grits continue the succession above the conglomerate,” and “ rain- spot breccia [i.e. rock like the underlying breccia at Green’s section | recurs above the supposed unconformity.” Now, if the authors could point to any clear section in which a rock undoubtedly belonging to the banded-slate series, whether a grit, a breccia, or a slate, can be seen overlying Green’s conglomerate in regular sequence, it would be fatal to my account of the rocks. This ought not to be a difficult matter, somewhere along the line of junction depicted on their map, but they do not point to any such section ; they use the ambiguous phrase “continue the succession.” If they cannot do so, but only assume that the “grit” and “ rain-spot breccia,” from their position to the north-west, i.e. in the direction of the supposed dip, of the conglomerate, must lie above it, the circularity. of their ‘“ proof” leaves nothing to be desired. _ On the other hand, I have searched in vain for such a section, but have only found patches of conglomerate overlying slates, as figured by Professor Green, not only immediately above his section but also to the north-west of it. The ground about here, however, is low and hummocky, and does not yield good sections. Further up the hill it is more hopeful. Above the Fachwen road the junction runs obliquely up the hill, making a large angle with its former direction. According to my opponents’ explanation, it is the lower beds here that form the higher ground, which they account for by giving the synclinal axis a dip towards the lake.’ Along the line of junction here there are some clear sections which are so fatal to my critics’ views that I am sure Miss Raisin cannot have seen them, as she could never have suppressed them if she had, especially as I alluded to them in my former paper. They are shown in Fig. 7. They are found a little to the north-east of the spot where I marked + on my map. ‘The first is near to the angle of a wall, where it curves round as shown on the 6 inch ordnance map. They cannot be missed, and they speak for themselves. The drawings represent nearly vertical faces, and the sides of the crags show that the conglomerate is not carried down behind the slate. The underlying slates are continuous as far as can be seen down to the tramway, and the conglomerate is of the same type as all three in that section. Other similar sections continue the line till we are removed only by a narrow valley from the continuation of the conglomerate adjoining the. felsite, the only visible rock intervening being a boss of greenstone. I claim that the test proves my reading to be right.’ 1 They do not explain how they get the synclinal down again into the further valley consistently with their mapping of the beds; nor do they account for the - enormous expansion of the strata between the conglomerate and slate compared with the tramway. Y Bigl summit is also represented as on slates, and not on laminated grits, but this may be an unintentional error. * Tt is also in accordance with Sir A. Ramsay’s section. 224 Rev. J. F. Blake—The Llanberis Unconformity. In my paper I said that these conglomerates crossed the hill horizontally, and at this statement my assailants make themselves merry. No doubt it would have been more correct to say that they form a slight synclinal, as indicated on Sir A. Ramsay’s figure in his Fie. 7.—Sections on Y Big] showing conglomerate lying on banded slate. A, B, C are in order from east to west. memoir; but the dips Miss Raisin quotes have nothing to do with the matter. If my assailants will look at my former fig. 3 and my present Fig. 7 they will see that there are all varieties of dip to choose from, from 90° downwards, but then they have overlooked Rev. J. F. Blake—The Llanberis Unconformity. 220 my words, “eliminating contortions.” If I spread out a fan on a table it may be said to lie horizontally upon it, yet all its parts will be highly inclined, and even the horizon itself on a stormy day at sea has not a single level spot upon it. In sach a squeezed district as Y Bigl it is not by local dips in individual sections, but by the position of corresponding outcrops, that we must judge of the lie of the stratum as a whole. The Microscopic Evidence. But what does the microscopic evidence amount to? That some of the minuter fragments (for they require the microscope to see most of them) are derived from the same kind of rocks, whether they be found in Cambrian or Post-Llanberis strata. These rocks are for the most part of a common kind, with no particular character to render identity certain, but we will grant they are the same. At that early epoch there was not much choice of materials to derive a fragment from, and any of them must have come either from Cambrian rocks themselves or from the Pre-Cambrian of the neighbourhood. In the wearing down of the Cambrian strata to make the conglomerates, the elements of the coarser rocks in them would yield smaller elements to the succeeding rocks, and these would be found in the matrix. But the character of the later rock would be shown by the larger fragments it contains. The coarser Post-Llanberis rocks are always thus distinguishable. The rederivation of some parts of the conglomerates is interestingly shown at Moel Tryfaen, where one of the pebbles is itself conglomeratic. It is not the fragments that are identical in the two series that present any difficulty, but rather the origin of those larger stones whose home we can find neither in Cambrian nor Pre-Cambrian rocks, but which closely resemble rocks of Post-Llanberis age. Some of these perhaps might be matched approximately in Anglesey, but they seem too large to have come so far. I tbink it not at all an unreasonable hope that we may some day find a fossiliferous pebble. I much regret that my opponents in this matter should have taken up the other side of the question, for, if they had sought to do so, there is no one more likely to be able to tell us whence the large pebbles may have come. In such an investigation the microscope would be doing its proper work; but it cannot prove by the similarity of small fragments the continuity of the deposits containing them, any more than it can disprove by the difference of the fragments the identity of two conglomerates, as has been already shown in the case of Twt Hill and Careg Goch. The worker with the microscope must not forget that in geology he is the servant of the stratigraphist, for until he knows the conditions of occurrence of his rocks his account of them has no geological value. It is therefore quite beyond his province to attempt to prove microscopically such a stratigraphical conclusion as the non-existence of an unconformity. The attempt in the present instance is founded on the assumption that rocks formed when “the _ Same rocks were undergoing denudation” must belong to the same DECADE IV.—VOL. V.—NO. VY. 1d 226 Notices of Memoirs—Artificial Diamonds. series, and cannot be divided by an unconformity. That this assump- tion is unwarranted has again and again been proved. The break at the base of the Llandovery alluded to by our authors is, both in Shropshire and at Llandovery, between rocks of very similar character; and such is the case, it is generally stated, between the upper and lower parts of the Old Red Sandstone in Herefordshire, and between the Elgin and the Old Red Sandstone in Scotland. In most of these cases the separation is effected by the aid of the fossils, but in the present case stratigraphy has to do the work alone, and it is perfectly capable of doing it. I trust that in the above remarks I may in no case have made a statement without at the same time indicating plainly how it may be checked, nor quoted my own opinion without giving any reasons for it, both of which procedures I hold to be inconsistent with scientific argument. aN Oana S (psy Nira MeO) ae1syS - I.—HEeERSTELLUNG VON DIAMANTEN IN SILIKATEN, ENTSPRECHEND DEM NATURLICHEN VORKOMMEN IN Kapianpr. Vortrag gehalten im Verein zur Beforderung des Gewerbfleisses am 7 Februar, 1898, von I. FrrepLanpER. (Berlin, 1898.) (ArtirictraL Propuction oF Diamonpd IN SILICATES, CORRESPONDING to THE ActuaL Mopse or Occurrence In SoutH AFRIvA.) i the recent diamond-making experiments of M. Moissan, fused iron rich in carbon was allowed to cool in such a way that the separation of the excess of carbon took place under pressure, and it was thought that a high pressure was necessary to the success which had been attained. It is now known that the necessary pressure is not very high, for microscopic diamonds have been found as normal constituents of ordinary cast iron. In South Africa no iron is present in the metallic state in the diamond-bearing rock, although it is largely present as a chemical constituent of the stony matter. Hence, in regarding Moissan’s method as being possibly identical with the one by which the South African diamonds had been formed, it was necessary to surmise that the crystals, after formation in the molten iron at some great depth below the earth’s surface, had floated into the molten silicate-material above. It was, however, soon pointed out that the diamond-bearing rock, if in a state of fusion at small pressure, dissolves any diamonds contained in it. Dr. Friedliinder fused a small piece of olivine, a centimetre in diameter, by means of a gas-blowpipe, kept the upper portion in the molten state for some time by playing upon it with the flame, and stirred it with a little rod of graphite. After solidification the silicate was found to contain a vast number of microscopic crystals, but only in the part which had been in contact with the carbon. These_ Dr. Friedliinder has subjected to a careful examination. They are octahedral or tetrahedral in form, are unattacked by hydrofluoric and sulphuric acids, have a high refractive index, sink slowly in, Notices of Memoirs—Diatomaceous Earth. 220 methylene-iodide, burn away when heated in a current of oxygen, and are unaltered if heated in a current of carbonic acid: the stony matter containing them scratches corundum. Hence Dr. Friedlander infers that they are diamond, and that the South African diamond may have been actually formed, as already sug- gested, by the action of a molten silicate, such as olivine, on graphite: carbonaceous shales are interrupted by the diamond- bearing rock, and numerous fragments of the shale, much altered, are found enclosed in the rock itself. The paper is illustrated with seven micro-photographs. I].—Nors on THE OccurReNcE oF DiaTomMAcrous HarTH AT THE WarrumBuncie Mounraiys, New Sourn Watuss. By Professor T. W. Epcewortu Davin, B.A., F.G.S. Proc. Linn. Soc. New South Wales, 1896, pt. 2, pp. 261-268, pls. xv—xvii. DiaromacEous Harta Deposits of New Sourn Watss. By G. W. Carp, F.G.8., and W. S. Dus. Records Geol. Surv. New South Wales, vol. v, pt. 3, 1897, pp. 128-148, pls. xii—xv. EPOSITS of Diatomaceous Harth occur not infrequently in Victoria and Queensland as well as in New South Wales, but so far there is no record of them in South Australia or in Western Australia. They are widely distributed in the older colony of New South Wales, for deposits are known at Cooma, about 260 miles to the south of Sydney; at Bathurst and the Mundooran district, 250 miles to the west; and also in the Warrumbungle Mountains, the Richmond River district, and at Barraba, from 800 to 350 miles to the north of Sydney. | At Cooma the deposit is over 20 feet in thickness; it lies in a hollow partly inclosed by hills of basalt, and is now only covered by surface soil. In the Warrumbungle Mountains there is a bed of diatomaceous earth 3 ft. 9 in. in thickness, interstratified in trachytic rocks, which are regarded by Professor David as of early Hocene or late Cretaceous age. In the Richmond River district the earth is found in depressions of scoriaceous basalt, and is overlaid by beds of the same material. At Barraba the diatom bed is eight feet in thickness, with a single intermediate band of coarse sand two inches in thickness ; beneath it are mudstones and lava fragments imbedded in diatomaceous material, and it is overlaid by a flow of basalt considered by Mr. EH. F. Pittman to be of Miocene age. This covering of basalt is now the summit of an elevated tableland. In these various deposits there is a very close resemblance in the character of the diatomaceous earth, which is a light, whitish, powdery material, typically similar to that known from other parts of the world. In some instances the siliceous constituents have been partially dissolved, and now form bands and nodular masses of hard, homogeneous, colloid silica. Chemical analyses show from 81 to 97 per cent. of silica, with, as a rule, small amounts of ferric oxide, alumina, and carbonates of lime and magnesia. Microscopic examination shows, further, a very singular uniformity in the diatoms composing these different deposits in New South 228 Reviews—A. OC. Seward’s Fossil Plants. Wales, for they consist almost exclusively of two or three varieties of the genus Melosira, and, rarely, a few examples of Navicula. With the diatoms there is also a small proportion of acerate spicules of fresh-water sponges. The markings of the diatoms are as perfectly preserved as in recent forms. JDetrital materials are absent in the beds, but in a few instances impressions of leaves of plants have been noticed. All the deposits are distinctly ‘of fresh-water origin, and probably of Tertiary age. Professor David considers that the constant association of volcanic rocks with the diatomaceous beds is not accidental, as probably hot springs, and the lavas also, furnished supplies of silica to the lakes in which the diatoms lived. It is evident that the preservation of these beds is ig many instances due to being overlaid by basaltic and trachytic avas. The diatomaceous deposits in Queensland, like those of New South Wales, mainly consist of Jelosira, but in those of Victoria the variety of diatoms is considerably greater, and fourteen genera have been enumerated in some of the fresh-water beds. Cue I5% Jt) Wh JE deh Wh Sh. J.—Fosstz Puants. For Students of Botany and Geology. By A. C. Szwarp, M.A., F.G.S. Vol. I. 8vo; pp. xviii, 452, with 111 illustrations. (Cambridge: Messrs. C. J. Clay & Sons, 1898. Price 12s.) ALAOBOTANY is no new creation of the fin du siécle, although, indeed, the subject has undergone considerable modification with the advance of botanical knowledge, more especially since it has been so largely assisted by the advances made in histological research. We cannot but recall with gratitude the labours of such men as Sternberg, A. Brongniart, Lindley and Hutton, Goppert, Bowerbank, Schimper, Hooker, Williamson, Carruthers, De Saporta, Grand’ Eury, and many others, who have paved the way for the botanist of to-day who desires to take up the study of Fossil Plants. The author of the present volume is already favourably known as filling the office of Lecturer in Botany in the University of Cambridge, and has been a worker for the last ten years at paleeobotany, one of his early papers having appeared in this Magazine for 1888 (p. 289) ; he is also the author of two volumes of a ‘Catalogue of Mesozoic Plants in the British Museum” (1894-5), and of several other papers of importance communicated to the Geological Society and — elsewhere. He tells us that “The subject of Paleeobotany does not readily lend itself to adequate treatment in a work intended for both geological and botanical students. The botanist and geologist are not always acquainted with each other’s subject in a sufficient degree to — appreciate the significance of paleeobotany in its several points of contact with geology and recent botany. . . . . It ueeds but Reviews—A. C. Seward’s Fossil Plants. 229 a slight acquaintance with geology,” he thinks “for a botanist to estimate the value of the most important applications of paleeobotany ; on the other hand, the bearing of fossil plants on the problems of phylogeny and descent cannot be adequately understood without a fairly intimate knowledge of recent botany.” ‘The student of elementary geology is not, as a rule, required to concern himself with vegetable paleontology, beyond a general acquaintance with such facts as are to be found in geological textbooks. The advanced student will necessarily find in these pages much with which he is already familiar; but this is to some extent unavoidable in a book which is written with the dual object of appealing to botanists and geologists.” While we cordially admit that “a fairly intimate knowledge of recent botany” is needful, if one proposes to take up such difficult questions as “the bearing of fossil plants on the problems of phylogeny and descent,” yet, on the other hand, the recent botanist who takes up the study of fossil plants with only “a slight ac- quaintance with geology ”’ is quite as likely to come to grief. Indeed, the botanist who ventures into the domain of paleobotany must be well-equipped with geological, mineralogical, and chemical knowledge, if he would attempt to interpret correctly the many structural and stratigraphical problems which lie before him at the very threshold of his investigation. The first chapter is devoted to a historical sketch showing the dawn and development of geological ideas, more particularly those relating to fossil plant-remains ; and the gradual evolution of accurate and intellizent observation which superseded the theorists of the last century. In the second the author treats of the relation of palao- botany to botany and geology. Here one naturally finds the methods of using fossils by the stratigraphical geologist, solely interested in determining the relative age of fossil-bearing rocks, contrasted with the intelligent study of fossils by the zoologist and the botanist, anxious to inquire into questions of biological interest which centre round the relics of ancient faunas and floras. Alas! how few zoologists really interest themselves in fossil remains of extinct animals, seeing neither form nor comeliness, nor anything to desire in them! Indeed, our author admits that “the botanist, whose observations and researches have not extended beyond the limits of existing plants, sees in the vast majority of fossil forms merely imperfect specimens, which it is impossible to determine with any degree of scientific accuracy”! ‘He prefers to wait for perfect materials; or, in other words, he decides that fossils must be regarded as outside the range of taxonomic botany.” This has been really the attitude of both zoologists and botanists with regard to paleontology until within the last twenty years. Now all is changed, and the geologist is told by the biologist that in the future he need not concern himself with fossil organic remains; they will be taken over into abler hands than his own and properly dealt with. We are heartily glad to hear that this is to be so; but where, we venture to ask, would our science have been 230 Poniee Al C. Seward’s Fossil Plants. during the past fifty years if we had not maintained a school of paleontologists, who have kept alive an interest in fossil remains, and who have been content to study and describe, to the best of their ability, even the imperfect specimens which were obtained. without waiting for the perfect materials which were not attainable ? Referring to the dual aspect of paleontology, as treated of by the biologist and the geologist, Mr. Seward appropriately quotes Humboldt, who fifty years ago wrote: “The analytical study of primitive animal and vegetable life has taken a double direction. The one is purely morphological, and embraces especially the natural history and physiology of organisms, filling up chasms in the series of still living species by the fossil structures of the primitive world. The second is more specially geognostic, considering fossil remains in their relations to the superposition and relative age of the sedimentary formations.” To this we might now add that the one furnishes a guide to the past history and records the modifi- cations which the ancestors of still living forms have undergone ; the other shows us the life-range of each form in time and often its former distribution over the earth as well. On the subject of ‘Fossil Plants and Distribution ” we cordially agree with the author. ‘The present distribution of plants and animals represents one chapter in the history of life on the earth; and to understand or appreciate the facts which it records we have to look back through such pages as have been deciphered in the earlier chapters of the volume. . . . . In the case of particular genera the study of the distribution of the former species, both in time and space, that is geologically and geographically, points to rational explanations of, or gives added significance to, the facts of present-day distribution. That isolated conifer, Ginkgo biloba, L., now restricted to Japan and China, was in former times abundant in Europe and in other parts of the world. It is clearly an exceedingly ancient type, isolated not only in geographical distribution but in botanical affinities, which has reached the last stage in its natural life. The mammoth trees of California (Sequoia sempervirens and SS. gigantea) afford other examples of a parallel case.” * The author takes us through a chapter on Geological History showing how strata have been built up; and then one on the preservation of plants as fossils. Both these subjects are carefully illustrated, and the student ought to be able to grasp some very good and clear notions on these subjects as he reads this part of the book. A tougher chapter follows (v) “On the Difficulties and Sources of Hrror in the Determination of Fossil Plants,” all of which is — excellent reading; but the student working at the present day with the vast added lights invented for him in the past thirty or forty years, need 70th, like the Pharisee of old, thank God for his more exalted position to-day, nor forget entirely that but for the — 1 See the eloquent address by Professor Asa Gray to the American Association : Silliman’s Amer. Journal, October, 1872, p. 282. Reviews—A. C. Seward’s Fossil Plants. 231 labours of past generations of workers, he and his Professors also might be priggishly discoursing with Dr. John Woodward on the exact time of year when the Deluge took place; or discover with Dr. Scheuchzer, of Zurich, in a giant fossil salamander from Oeningen, the image of “ Homo diluvii testis.” Under the subject of Nomenclature and the Rule of Priority, Mr. Seward writes: “Some writers would have us conform in all eases to this rule of priority, which they consistently adhere to apart from all considerations of convenience or long-established custom. . . . A name may have been in use for, say, eighty years, and has heen per fectly familiar as-the recognized designation of a particular fossil ; it is discovered, however, that an older name was proposed for the same species ninety years ago, and therefore, according to the priority rule, we must accustom ourselves to a new name in place of one which is thoroughly established by long usage.” In all this, and much more under this head, we are heartily in accord with the author, and would go so far as to follow the example of Pope Gregory in the “ Ingoldsby Penance,” and say— ““ Go fetch me a book! go fetch me a bell As big as a dustman’s! and a candle as well: I’ll send hin—where, good manners won’t let me tell !”’ In Part II, Systematic, the author begins with the simplest type of very minute organisms, the THaLLopHyra, as Perediniales (small single-celled organisms); he then treats of Coccospheres and Rhabdospheres. Peredinium was described by Ehrenberg in 1836 from Cretaceous beds in Saxony, while the others occur in the English Chalk and Lias, and all have been found nearly everywhere in sea-water. Other microscopic bodies are also noticed by the author, as the Chroococeaceex, Girvanella, Zonatrichites ; Schizomycetes (Bacilli) ; Alge. Among these last, the student is warned against the many spurious fossil organisms pointed out by Williamson, Nathorst, and others, which simulate plant-remains. ‘Then follow accounts of true fossil Algee and of objects simulating Alge. ‘To these succeed recent and fossil Diatoms ; Chlorophycez, Siphonee, and Confervoidee ; Rhodophycez ; Phzeophyces ; Myxomycetes ; Fungi. Most of these forms are much too obscure, and involve problems far too difficult for the elementary student to attack. In the Characez we begin to reach forms which even the young student of palezobotany may readily recognize and appreciate, occurring as they do in the Jurassic and Wealden, and in many of the Tertiaries of England and France. Thence we pass on to the second half of the book, viz., the Mosses, the Hquisetales or Hquisetaceee, with chapters on Calamites and Sphenophyllum. Here structures of stems, roots, foliage, the spore- cones and spores of these plants, give abundant subjects for illus- tration, and we should have been glad if more could have been given had space permitted. A list of authors and their works referred to in the text and an index usefully and appropriately end this volume. 2032 Reviews—Sir A. Geikie’s Geological Map. As higher forms are reached no doubt the subject-matter will increase in interest. The author publishes in his preface the names of many people who have helped him in his work, but to none is he more indebted than to Mrs. Seward, “who has drawn by far the greater number of the illustrations,” and we may add very well done indeed! In Volume II the author promises us that the systematic treatment of plants will be concluded, and the last chapters will be devoted to such subjects as geological floras, plants as rock-builders, fossil plants and evolution, and other general questions connected with paleobotany. In conclusion, we cannot part from Mr. Seward without expressing our conviction that the volume before us will prove a most acceptable addition to the Biological Series of Cambridge Natural Seience Manuals issued by Messrs. C. J. Clay & Sons from the University Press. {1.—A New Geotocican Map or Encianp and Watss, reduced from the Ordnance and Geological Surveys, and published with Government Authority under the direction of Sir ARCHIBALD Gerkiz, D.C.L., LL.D., F.R.S. With Descriptive Text. By JoHN BarrHotomew & Co. Mounted on cloth and in ease, 12s. 6d.; on cloth with rollers and varnished, 17s. 6d. (Hdin- burgh, 1897.) HIS map is on a scale of an inch to ten miles, and is slightly ‘larger than Ramsay’s hand-coloured map published by Stanford. The colour-printing adopted by Bartholomew is excellent, but the tints are not quite so effective as those iaid down by hand on the older map, and this is noticeable more especially as regards the Cretaceous and Tertiary strata. The colours, however, are clear and transparent, the topography is accurate, and the railways are shown up to date, including nearly the whole of the Great Central Railway, which is not yet open to the public. Those parts of Scotland, Ireland, and France which are included in the map are coloured geologically, and there are four longitudinal sections to depict the structure of the country from Holyhead to Beachy Head, from Denbigh to Saltfleet, from the Solway Firth to Flamborough Head, and across the Isle of Wight. The map is also accom- panied by 28 pages of explanatory notes, which give a concise account of the strata. Future work will no doubt introduce some detail into the large area of ‘Lower Silurian” rocks in Central and South Wales, and also into the Devonian rocks. We note that the Plymouth limestone is coloured blue, but — the Torquay and Brixham limestones are not so distinguished. We observe that the colour adopted for Triassic marls is not at first sight readily to be distinguished from that of the Permian marls and sandstones; but there is much yet to be done in ~ discriminating Permian and Trias in the field in the Midland and Northern Counties. The Rheetic beds are indicated in places where they have been mapped by the Geological Survey, but, as Reports and Proceedings— Geological Society of London. 233 remarked in the text, “this group of strata runs with singular persistence throughout England and Wales.” The price of this map is 12s. 6d., and as it is unquestionably the best geological map of England and Wales which can be con- veniently carried in the pocket, it should meet with a cordial welcome from all interested in the physical structure of our country. REPORTS AND PROCHEHEDINGS. GeoxtocicaL Society of Lonpon. I.—March 9, 1898.—W. Whitaker, B.A., F.R.S., President, in the . Chair. Professor J. W. Judd exhibited, on behalf of the Coral Reef Committee of the Royal Society, the lowest core (698 feet) from the boring at Funafuti (Ellice Islands), and drew attention to the remarkable changes exhibited by the rocks obtained at this depth. The core from this boring (a mass of material more than a ton in weight) had been sent to this country by Professor Edgeworth David, and was now being submitted to careful study. The last 20 or 30 feet of the boring was carried on in a rock which was of a very soft character, and highly but minutely crystalline. Microscopic examination shows that the rock is almost completely converted into a mass of very small rhombohedra, the organic structures being nearly obliterated ; while a preliminary chemical examination seems to indicate that magnesia has been introduced into the rock to a con- siderable extent. ‘I'he complete study, microscopical and chemical, of all the stages of the change which has taken place in this rock— a study which will be undertaken by Mr. C. G. Cullis—promises to throw much light on processes of rock-formation of very great interest to the geologist. The following communications were read :— 1. “Note on Clipperton Atoll.” By Rear-Admiral Sir W. J. Wharton, K.C.B., F.R.S., Hydrographer to the Admiralty. (Com- municated by Sir Archibald Geikie, D.Sc., F.R.S., F.G.S.) This atoll, 600 miles from North America, in lat. 10° 17’ N., long. 109° 13’ W., possesses a lagoon which is now completely cut off from the sea. In this is a perfectly round hole where soundings of 20 fathoms or more are reported, on the authority of Mr. Arundel, and even deeper ones on that of the captain of a merchant-vessel. On the coral ring there rises a mass of modified trachyte, the subject of the following communication, about 60 feet in height. The great depth of the lagoon and the rock-mass on the ring are not compatible with the origin of the reef by subsidence or outward growth; and the possible hypothesis is put forth that this reef had grown on the lip of a volcanic crater, or on an island, such as Krakatao, in which the interior has been enlarged and deepened by volcanic explosion. 234 Reports and Proceedings—Geological Society of London. 2. “A Phosphatized Trachyte from Clipperton Atoll.” By J. J. H. Teall, Esq., M.A., F.R.S., V.P.G.S. Specimens from the projecting rock described in the preceding communication are dark brown, white, or cream-coloured. The brown specimens are trachytes, composed of glassy phenocrysts of sanidine set in a groundmass of microlitic felspars with brown inter- stitial matter. The light-coloured rocks are more or less altered trachytes, in some of which the glassy phenocrysts of sanidine may still be recognized. Analyses of several specimens show that the rocks all contain varying amounts of phosphoric acid, as indicated by the following table :— IL. II. III. per cent. per cent. per cent. SiO, ... abc eee 54°0 a 43-7 300 2°8 PoO5 jaa. 300 200 8-4 306 17:0 20% 38°) Loss on ignition ils 371 50 12°3 506 23:0 The last specimen consists of 95 per cent. of hydrated phosphate of alumina, with some iron, having thus a composition allied to the so-called redonite from Redonda in the West Indies. The progressive alteration affects first the groundmass, then the microlitic felspars, and lastly the porphyritic crystals of sanidine; and it is probable that the change has been effected by solutions of alkaline phosphate and other compounds. derived from the droppings of sea-birds. A somewhat similar phosphate, shipped from Connétable Island off French Guiana, is referred to on the authority of Mr. Player. 3. “The Pliocene Deposits of the Hast of England.—Part I. The Lenham Beds and the Coralline Crag.” By F. W. Harmer, Hsq,, E.G:S. From the discussion of lists of fossils, a large number of sections, and a series of borings, the author endeavours to establish the following propositions :— I. With regard to the Lenham Beds: (a) That they are older than the Coralline Crag, thirteen out of sixty-seven mollusca found in them being characteristic Miocene or Italian Lower Pliocene forms unknown or very rare in the latter formation. (b) These beds had probably been upheaved, consolidated, and exposed to denudation before the deposition of the Coralline Crag, and may have been, as formerly suggested by Professor HE. Ray Lankester, the source from which the “boxstones” found at the base of the Suffolk Crag have been derived. These boxstones contain a fauna, not identical with, but of the same general — character as that of Lenham. (c) In the interval between the deposition of the Lenham Beds and the Coralline Crag the sea retired to the north, in consequence of the upheaval of the southern part of the area, as it did in - Belgium towards the close of the Diestien period. (qd) The Lenham Beds are most nearly, though not exactly, represented by the Zone & Terebratula grandis of Belgium, and 9 Reports and Proceedings—Geological Society of London. 235 possibly by some fossiliferous deposits recently discovered at Waenrode, near Diest, the Coralline Crag corresponding very closely with the Belgian Zone a Isocardia cor. II. With regard to the Coralline Crag: (a) That the junction of the Crag with the London Clay dips to the N.N.E. (b) That no satisfactory evidence, either stratigraphical or paleontological, is forthcoming to show that any divisions to be observed in this formation at Sutton are persistent at other localities, and that species which have been tabulated as charac- teristic of certain horizons are found also in other parts of the Coralline Crag, and often in the Red Crag as well. (c) That there is no evidence of any great subsidence, of deep- sea conditions, of great changes of climate, or of the operation of floating ice during the period. The climate was warmer than that of Britain at the present day, more nearly approaching that of the Mediterranean or the Azores. (d) That, so far from it being possible to separate this Crag into eight zones, the twofold division hitherto adopted, into shelly incoherent sands and indurated rock, can no longer be maintained, the latter being merely an altered condition of the former, as proved by the discovery of a section showing the two types passing laterally into each other. (e) That, with the exception of the base, this Crag forms a con- sistent and continuous whole, accumulated under similar conditions, namely, in the ‘form of submarine banks, piled up by currents in sheltered situations like that known as the Turbot Bank off the Antrim Coast and those at the south of the Isle of Man, where Professor Herdman’s “ neritic’ deposits occur. (f) That the German Ocean was less open to the north during the Coralline Crag period than at present, but that it was connected with the Atlantic by a channel over some part of the southern counties of England. III. With regard to the Red Crag: _ That it forms, with the exception of the Chillesford Beds and “the unfossiliferous sands of the Crag,” a continuous sequence of deposits arranged horizontally, and not vertically. It was a marginal accumulation of a sea slowly retreating to the north and east, as shown by the gradually increasing number of northern mollusca met with in this direction. Il.—March 23, 1898. — W. Whitaker, B.A., F.R.S., President, in the Chair. The following communications were read :— 1. “The Eocene Deposits of Devon.” By Clement Reid, Esq., F.L.S., F.G.S. (Communicated by permission of the Director- General of H.M. Geological Survey.) A re-examination of the area around Bovey has led the author to think that Mr. Starkie Gardner is probably right in referring the 236 Reports and Proceedings—Geological Society of London. supposed Miocene strata to the Bagshot period. Lithologically, as well as botanically, the deposits in Devon and Dorset agree closely. The gravelly deposits beneath the Bovey pipeclays are y also shown to belong to the same period, and not to be of Cretaceous date. This correction has already been applied by Mr. H. B. Woodward to a large part of the area. The plateau gravels capping Haldon are also considered to belong to the Bagshot period, for they correspond closely with the Bagshot gravels of Dorset to the east, and of the Bovey Basin to the west, and possess peculiarities which distinguish them from any Pleistocene Drift. 2. “On an Outlier of Cenomanian and Turonian near Honiton, with a Note on Holaster alius, Ag.” By A. J. Jukes-Browne, Esq., B.A., F.G.S. (Communicated by permission of the Director-General of H.M. Geological Survey.) Although an outlying patch of Chalk in the parish of Widworthy was mentioned by Fitton and marked on De la Beche’s map, it has not yet been described. The tract is about 44 miles south-west of Membury, 84 miles east of Honiton, and about 7 miles from the coast at Beer Head. The quarries at Sutton are almost entirely obscured by vegetation, but the following approximate section was obtained from a mason who formerly worked in them :— feet. 7. Flint-rubble ... bate dos BA wah) 2 Aeon [Zone of 7. gracilis.] 6. Soft white Chalk ... soc Gos >. 10 tor30 Hard Chalk... aoc ane eee ... About 20 [Zone of Rh. Cuvieri.] (§ 4. Freestone ae : doo 306 02 OD 3. Soft Chalk with green g erains be EtG cries 2. Hard cockly Chalk... aN seine ee 1. ‘‘Grizzle’’ (a hard calcareous sandstone). The Freestone, used locally for building, is evidently identical with the Beer Stone. Another small outlier of Turonian Chalk occurs at Wilmington, resting on hard quartziferous limestone with glauconitic grains, which yielded fossils indicating its equivalence with the uppermost Cenomanian beds of the coast-section. Below this come other sandstones, sometimes containing lumps of “grizzle,” giving a total thickness of 40 or 42 feet to these beds on the whole—a much greater thickness than is ever attained on the coast. A list of fossils is appended to the paper, and the author discusses the affinities of Holaster altus, throwing out the suggestion that there is a gradation from H. Bischoffi through H. altus to H. subglobosus. 3. ‘Cone-in-Cone: Additional Facts from Various Countries.” By W. 5S. Gresley, Hsq., F.G.S. Examples of flinty stone in the “ fire-clay series” of the Ashby coalfield exhibit “areas of conic structure, lying unconformably.” In the same stratum of shale are large masses of the same flinty rock, more or less coated with conic structures, which appear to have been formed out of layers of shale and ironstone. The Reports and Proceedings—Geological Society of London. 237 bending-up of the shale above the nodules and down below them, the close but unconformable covering of Permian breccia, and the staining of the whole section suggests, if indeed it does not demonstrate, to the author that the growth of the cone-in-cone took place subsequently to the deposit of the Permian breccia. Several American and other examples are described, and a series of con- clusions are appended to the paper. IlI.—April 6, 1898.—W. Whitaker, B.A., F.R.S., President, in the Chair. Professor T. Rupert Jones exhibited and commented upon a series of large stone implements, sent to Hngland by Mr. Sidney Ryan, from the tin-bearing gravels of the Embabaan in Swaziland (South Africa). They consist of fine-grained quartzite, chert, lydite, siliceous schist, and quartzites composed of breccia and grit-stones, one of the latter mylonized. He also exhibited some corresponding rock-specimens from the neighbouring Ingewenyaberg, with a map and section prepared by Mr. 8. Ryan. Some similar implements from the same district, lent by Mr. Nicol Brown, F.G.S., and some analogous implements of rough quartzite, from Somaliland, lent by the Rev. R. A. Bullen, F.G.S., were also exhibited. Professor H. G. Seeley exhibited the humerus of a Plesiosaurian in which the substance of the bone was almost entirely replaced by opal. He explained that the fossil was from the opal-mines of New South Wales. Externally there is no indication of its internal condition as a pseudomorph, and it had been broken to ascertain its commercial value as opal. It is translucent; of a bluish tint, with a slight red fire. So far as he was aware, it was the only example of a fossil bone in this condition; and he was indebted to Messrs. Hasluck, the opal merchants, for the opportunity of placing the specimen before the Fellows. The following communications were read :— 1. “On some Paleolithic Implements from the Plateau-Gravels, and their Evidence concerning ‘ Kolithic’ Man.” By W. Cunnington, Ksq., F.G.8. Although at first inclined to believe that the chipping on the “Holiths” of the plateau-gravels was the work of man, the author has been led to recant this opinion by the detailed study of specimens lent or given to him by Mr. B. Harrison. His reasons are mainly based on the facts that the chipping is of different dates, even upon the same specimen, and that it was produced after the specimens were embedded in the gravel. A further series of specimens, which, although not found actually mm sit in the gravels, present undoubted evidence that they came from these, are considered by the author to be of Paleolithic type. One of them appeared to have gone through the following stages :— first it was fashioned by man into a Paleolithic implement; then it 2038 Reports and Proceedings—Geological Society of London. was abraded, broken. and chipped along one edge in the same fashion as the alleged “ Holithic” working; finally it. was stained, marked with glacial striz, and covered with a thin layer of white silica. This implement appears to prove that Paleolithic man lived on the Kentish plateau before or during the deposit of the plateau- gravels, and that the ‘‘ Holithic”’ chipping is not the work of man. 2. “On the Grouping of some Divisions of Jurassic Time.” By S. S. Buckman, Esq., F.G.S. The author argues for an arrangement in the division of Jurassic time based upon the zoological phenomena of the Ammonite-fauna. He considers that such time-divisions should be related to the duration of Ammonite families. He divides the Jurassic Period into two epochs—the Hojurassic and the Neojurassic: the former the time when the Ammonite families of the Arietidee and their close ally the Hildoceratidee were dominant; the latter commencing just upon the extinction of these families, and being the time when the Stepheo- ceratide: held chief sway. The epochs are subdivided into ages, and the ages, again, are divided into hemeree—a hemera being the chronological unit. Reasons are given for the different subdivisions, and for commencing the Hojurassic Period with the rotiformis-hemera. The Hojurassic Period it is proposed to divide into four ages—the Sinemurian, the Pliensbachian, the Toarcian, and the Aalenian. During the Sinemurian age, whereof the zoological phenomenon is the acme and paracme of the Arietide, was deposited a part of the Lower Lias, beginning with the zone of Ammonites Bucklandi and ending with that of A. oxynotus. This age is divided into the following seven hemerz, stated in ascending order: rotiformis, Gmuendensis, Birchi, Turnert, obtust, stellaris, oxynott. During the Pliensbachian age, marked by the dominance of Deroceratidee and Amaltheids, was laid down the rest of the Lower and almost all the Middle Lias. It includes seven hemere, namely: raricostati, armati, Jamesoni, Valdani, striati, margaritati, spinati. During the Toarcian age, when the Dumortierig and a part of the Hildoceratidee were prominent, the following strata accumu- lated: a small part of the Middle and the whole of the Upper Lias, the Cotteswold Sands, the Midford Sands, and a portion of the Yeovil Sands. There are ten hemere: acuti, falciferi, bifrontis, Lillie, variabilis, striatuli, Struckmanni, dispansi, Dumorterie, Moorei. During the Aalenian age, when there was a preponderance of — another portion of the Hildoceratide which may be known as the LIudwigia-group, and of Hammatoceras, the rest of the Yeovil Sands and a part of the Inferior Oolite were the accumulated deposits. This age is divided into the following six hemera: ~ Aalensis, opaliniformis, scissi, Murchisone, Bradfordensis, concavt. Part of the Neojurassic division is separated into two ages. During the first, the zoological phenomenon is the acme and Correspondence—Professor M. E. Wadsworth. 239 paracme of Sonnining; during the second, the predominance of Parkinsonie. The paper contains a hemeral timetable of the Hojurassic Period and part of the Neojurassic, a genealogical table of Ammonite development during the same and a previous portion of time, notes on certain generic names, and a list of the Ammonite genera referred to. CO En Sa © INE aN S zeae A MECHANICAL THEORY OF THE DIVINING-ROD. Tue review in Nature (1897, pp. 568, 569) of a_publica- tion relating to the ‘“ divining-rod,” recalls to my mind a purely mechanical theory of that rod, which was given me years ago by a friend. . This theory has been repeatedly tested by me and shown to be correct in the presence of my classes. ‘The process is exceedingly simple. Take any forked twig of a reasonably tough fibre in the clenched hands with the palms upward. The ends of the limbs forming the twig fork should enter the closed fists on the exterior side of each fist, i.e. on the two sides of the clenched hands furthest from each other. When a twig is grasped in this position it will remain stationary if held loosely, or with only a moderately firm grasp; but the moment the grasp is tightened, the pressure on the branches will force the end of the twig to bend downwards. The harder the grip the more it must curve. The curvature of the twig is mechanically caused by the pressure of the hands forcing the limbs to assume a bent and twisted position ; or the force that causes the forked limb to turn downwards is furnished by muscles of the hands, and not from any other cause. The whole secret of the ‘‘divining-rod” seems to reside in its position in the hands of the operator, and in his voluntarily or involuntarily increasing the closeness of his grasp on the two ends of the branches forming the fork. If the above conditions are fulfilled the twig will always bend downwards—water or no water, mineral or no mineral; anyone can be an operator, and any material can be used for the instrument, provided the limbs forming the fork are sufficiently tough and flexible. It can be easily understood how an ignorant operator may deceive himself, and be perfectly honest in supposing that some occult force, and not his hands, causes the fork to curve downwards. M. KE. Wapsworru. Michigan College of Mines, Houghton, Michigan. 240 Correspondence—F. R. Oowper Reed, EGS. PLACOPARIA FROM THE SKIDDAW SLATES. Str,—As supplementary to the note published by Miss G. L. Elles in the March number of this Magazine (p. 141) recording the occurrence of Placoparia in the Skiddaw Slates, it may be of. interest to mention that one of the three specimens in the Wood- wardian Museum was correctly named and labelled as long ago as the year 1890, when it was collected by Mr. H. Kynaston, M.A., F.G.8., at Outerside during Professor Hughes’ geological excursion to the Lake District. The second specimen, which was obtained at the same time and locality, was identified by me in 1895, when I was rearranging the collection, and was duly entered with the other in my manuscript catalogue of the fossils of the Skiddaw Slates in the Woodwardian Museum. The third specimen, as Miss Elles has mentioned, comes from Ellergill, and is a recent gift from Professor H. A. Nicholson, F.R.S. F. R. Cowper REep. Woopwarpian Muszum, CAMBRIDGE. April, 1898. IMDS Crate Pay NINpHO WS. ——_@——_ New Georoctcat Survey Maps.—In our January number, p. 48, attention was drawn to the issue of several sheets of the General Geological Map of England and Wales (scale an inch to four miles), published by the Geological Survey. The fifteen sheets of the colour-printed edition have now all been issued; and (with the exception of the title-sheet, price 2s.) the price of each sheet is 2s. 6d. The total cost of the map is therefore £1 17s. It is to be hoped that some of the one-inch Geological Survey maps, such as that of “London and its Environs,” which in the hand-coloured form costs no less than 30s., or that of the Isle of Wight, price 8s. 6d., may ere long be issued in the cheaper form. GEOLOGICAL Survey.—The vacancy caused by the retirement of Mr. George Sharman, senior Palzxontologist on the Geological Survey, has been filled by the appointment of Mr. F. L. Kitchin, M.A., Ph.D., as Assistant Paleeontologist, under Mr. E. T. Newton, F.R.S., Paleeontologist. A ILiyex in a Duststorm.—The Castle Line mail steamer ‘Roslin Castle” arrived at Plymouth on February 22 more than two days later than usual, and Captain Travers reported an extraordinary experience. He stated that on Monday, February 14, the vessel met what appeared to be a dense fog, but it proved to be a sand- storm, the air being permeated with red sand from the Sahara Desert for over 900 miles. During this time the sun and stars were obscured, and no observations were possible until after Madeira was reached.— Daily Mail. West, Newman 1mp. 7x2 Decade IV. Vol. V. Pl. VIL. 5ax2 Geol. Mag. 1898. E.Drake del et kth. Kgyptian Corals. Geol. Mag. 1898. Decade IV. Vol. V. Pl. IX. lb x2 E. Drake del. et lth. ih gyptian Corals. West, Newman ump. EA THE GEOLOGICAL MAGAZINE. NEVE SERIES: | DECADE, iVae iO Fey. No. VI.—JUNE, 1898. ORIGIN At, AB rTietms I.—A Coxtiection or Hayprran Fosstz MApREPORARIA. By J. W. Gregory, D.Sc., F.G.S. (PLATES VIII AND IX.) HE collection of fossils belonging to the Geological Survey of HL Egypt which has been sent to England for description by Capt. H. G. Lyons, R.E., contains a series of forty specimens of corals, including representatives of nine genera and eleven species. Of the latter two are new. The horizons represented are as follows :— Pleistocene: Raised coral reefs at Jebel Zait. Middle Miocene—Helvetian : Camps 8 and 20 between Cairo and Suez; near Jebel Attaka, Jebel Owebid, ete. Upper Eocene: Fayum, in Lake Birket-el-Qurun. Lower Eocene—Libyan: Dungul Wells and near Silsila, Upper Egypt. Turonian: Abu Roasch, west of Gizeh. A record of a species of Fungia from the Pleistocene deposits, based on some specimens in the British Museum collection, is included in the present paper. The principal works on the Egyptian coral-faunas are the following :— C. G. Ehrenberg. ‘“ Beitrage zur physiologischen Kenntniss der Corallenthiere im Allgemeinen, und besonders des rothen Meeres, nebst einem Versuche zur physiologischen Systematik derselben”: Abh. k. Akad. Wiss. Berlin f. 1832 (1834), pp. 225-880. C. B. Klunzinger. “Die Korallthiere des rothen Meeres,” pts. ii and ili. Berlin, 1879. Joh. Felix. ‘‘Korallen aus igyptischen Tertiirbildungen”: Zeit. deut. geol. Ges., vol. xxxvi (1884), pp. 415-453, pls. iii-v. H. Pratz. ‘ Hocine Korallen aus der lybischen Wiiste und Aegypten”’: Beitr. Geol. Pal. libysch. Wiiste, pt. ii (1883), pp. 219-288, pl. xxxv. DaCADE IV.—VOL. V.—NO. VI. 16 242 Dr. J.W. Gregory—Egyptian Corals. Th. Fuchs. “Beitrage zur Kenntniss der Miocinfauna Aegyptens und der libyschen Wiste”: Beitr. Geol. Pal. libysch. Wiiste, pt. ii (1883), pp. 18-66, pls. vi-xxii. K. Mayer-Eymar. ‘Die Versteinerungen der tertiiren Schichten von der westlichen Insel im Birket-el-Quriin See”: ibid., pt. 11 (1883), pp. 67-78, pl. xxiii. I. PLEISTOCENE. Genus SYMPHYULLIA (Edwards & Haime), 1848. SYMPHYLLIA ERYTHRACEA ? (Klunzinger), 1879. Isophylliia erythracea? Klunzinger, 1879: ‘Korallthiere roth. Meer.,” pt. III, Die Steinkorallen, (11) Astraiaceen und Fungiaceen, p. 10, pl. i, fig. 10; pl. ix, fig. 9. . Distripurion.—Recent: Red Sea (Klunzinger). Pleistocene : Raised reef at Jebel Zait; Coll. Geol. Surv. Egypt, No. 6382. tEMARKS.—The collection includes a fossil which is probably the cast of a massive Symphyllia, and agrees more closely in general appearance with Symphyllia erythracea than with any other species. The specimen is not in a condition for positive determination. Walther! has figured a coral from the raised reefs of Jebel Hamman Musa on the coast of the Gulf of Suez, opposite the locality whence the Egyptian Survey specimen was obtained, which probably also belongs to this species. Pourtalés? and Duncan*® have both urged that Isophyllia and Symphyllia should be merged, a proposal with which I agree: this species is therefore included in Symphyllia, as that name has three years’ priority. Genus ORBICELLA, Dana, 1848. OrBICELLA ForsKatt (Edwards & Haime), 1849. Astrea Forskaliana, Edwards & Haime, 1849, ‘“‘ Mon. Astr.,” No. 4, pt. 3: Ann. Sci. nat., Zool., ser. 3, vol. xii, p. 100. ? Favia tubulifera, pars, Klunzinger, 1879: op. cit. p. 28, pl. x, fig. 2 (non pl. iui, fig. 6). Orbicella mammillosa, Klunzinger, 1879: ibid., p. 49, pl. v, fig. 5; polepxc ation: Distripution.—Recent: Red Sea. Pleistocene: Low-level reefs of Jebel Zait, Egypt; Coll. Geol. Surv. Egypt, No. 22. High-level reefs (150 metres), near Jebel Zait; Coll. Geol. Surv. Egypt, No. 375. The collection of Pleistocene corals from the shores of the Gulf of Suez includes four specimens of Orbicella, which I refer to 1 J. Walther, ‘‘ Die Korallenriffe der Sinaihalbinsel’’: Abh. k. sich. Ges. Wiss., vol. xxiv (1888), pl. v, fig. 9. 2 L. F. de Pourtalés, “ Deep-Sea Corals’’: Ill. Cat. Mus. Comp. Zool., No. iv ~ (1871), p. 70. ° P. M. Duncan, “ Revision of Madreporaria’’?: Journ. Linn. Soc., Zool., vol. xviii (1884), p. 91. Dr. J. W. Gregory—LEgyptian Corals. 243 Orbicella Forskali (Hd. & H.). This determination, I feel sure, is not free from doubt, as I have not been able to see specimens of the four following recent “species ””—Orbicella Forskali (Eid. & H.), O. laxa, Klnz., O. mammillosa, K1nz., and Favia tubulosa, Klnz. “The specimens agree in every essential character with the original diagnosis of Orbicella Forskali. That coral was then said to have septa belonging to the fourth cycle, which was not, however, stated tobe complete. The four fossil specimens have three complete cycles of septa and representatives of the fourth. The only difference between the corals and the original description of O. Forskali is, that the columella is more strongly developed, which, however, is not an important character in Orbicella. But in the “Histoire Naturelle des Coralliaires,” Milne Edwards and Haime put Orbicella Forskali into the group of species having four complete eycles. This was probably an error, and possibly a mere accident. Klunzinger had not seen specimens of the species, but he accepted the presence of four complete cycles from Milne Edwards and Haime’s action in 1857, and founded for an allied coral with the fourth cycle incomplete the species O. mammillosa. The coral, however, among Klunzinger’s series with which these Pleistocene specimens most closely agree is Favia tubulifera, Kinz. Klunzinger gave two figures of this species, pl. ili, fig. 6, and pl. x, fig. 2, the characters of which do not seem to me quite consistent. The former is a true Favia: the corallites are irregular, triangular or elongated, and in one case, at least, is clearly under- going fission. But the latter specimen (pl. x, fig. 2) shows only the characters of Orbicella; that may be due to the fact that the specimen figured is small; but as far as that figure goes the specimen appears to be specifically identical with Orbicella Forskali. Faurot! has recorded this species from the Pleistocene deposits of the southern end of the Red Sea in the Gulf of Tadjura. Favia denticulata (EU. & Sol.) has corallites somewhat of the same type as regards numbers of septa, development of columella, and size; but the calice is very much deeper, and the septa thinner and more equal in size. Genus FUNGIA, Lamarck, 1801. Funera parenta (Hl. & Sol.), 1786. _ Var. toputata, Klunzinger, 1879.’ The British Museum collection includes three small specimens (R. 1,808) of Fungia from the Egyptian Pleistocenes, which may be conveniently recorded here. The specimens are young, having the following dimensions :— Height. Diameter. (a) 12 mm. o8e Ss 30 by 35 mm. (0) 9 mm. ah Bhs 30 by 33 mm. (c) 7 mm. Fhe aa 33 by 37 mm. 1 L. Faurot, ‘‘Une Mission dans la Mer Rouge (Ile de Kamarane) et dans le Golfe d’Aden (Aden et Golfe de Tadjoura)’’: Arch. Zool. Exper., ser. 2, vol. yi, p. 121. 2 Klunzinger, op. cit., p. 62, pl. vii, fig. 4; pl. vill, fig. 2. 244 Dr. J. W. Gregory—Egyptian Corals. The form varies considerably: the base is concave in a, but convex in 0, and flat in c; the shape of a is somewhat reniform, but b and ¢ have irregular marginal lobes. The specimens present remarkable resemblances to F. repanda, Dana,! with which they agree in general form, in the depression round the corallum, half-way between the centre and margin, in the small number and thickness of the septa, and in the proportions of the calicular fossa; but the under surface is not coarsely papillose, and the septal teeth are not turned backwards (see Pl. IX, Fig. 5), though this character may have been destroyed by weathering. The resemblance to F. repanda necessitates a comparison of these corals with F. scruposa, Klnz.,? which agrees with these specimens in the prominence of the expanded inner ends of the septa; but that species, like F. repanda, differs by the characters of the coste, which are coarsely and abundantly dentate. J. valida, Verr.,® which Klunzinger has figured from the Red Sea, agrees in its septal characters, but differs by the great inequality of the costa. Klunzinger has doubtfully included Verrill’s F. Haimei* as a synonym of his F. patella var. lobulata. But Verrill states that F. Haimei differs from F. discus by having on its nearly equal cost numerous sharp curved spines, instead of irregularly scattered obtuse spines. In this respect the three Egyptian specimens differ from F. Haimei, as they have low, blunt, scattered spines on the coste (Pl. IX, Fig. 5). Their general characters, however, agree so closely with those of F. patella that they may be safely included in that species as members of the variety lobulata. II. MIOCENE. Genus STYLOPHORA, Schweigger, 1819. STYLOPHORA ASYMMETRICA, Nov. D1AGNosis. Corallum massive, flat-topped, growing in successive horizontal lamin. The upper surface is ornamented by the long, sharp, well-raised septo-costee. Corallites very large, separated by exothecal areas slightly narrower than the diameter of the corallites. Calices rarely deep; usually small and raised above the general surface of the corallum. The calices rest on the flat-topped columella, and are bounded laterally by the highly raised, exsert septa. Septa irregular in development. There are typically six large, thick primary septa fused to the columella, and six short secondary septa, of which the inner margin is free. But this diagrammatic 1 Dana, ‘‘ Zooph. Explor. Exped. Wilkes,’’ vol. viii (1848), p. 295, pl. xix, figs. 1-3. 2 Klunzinger, op. cit., p. 63, pl. vii, fig. 2; pl. viii, fig. 1. 3 Verrill, ‘“ List of Polyps’? : Bull. Mus. Comp. Zool., vol. i (18€4), p. 41. 4 Verrill, op. cit, p. ol. Dr. J, W. Gregory—Egyptian Corals. 245 arrangement is seldom seen. There are usually three primary septa on one side and four or five on the other ; the septa are rarely bilaterally symmetrical, and the arrangement is heptameral or octameral, rather than hexameral. Primary septa highly exsert. Columella, massive, flat-topped. Dimensions. Horizontal lamine ia lee baie an: 5 in 12mm. Average diameter of corallite ... ae vad 6°5 mm. Average distance of calicinal centres... ear 11 mm. Distrisution.—Middle Miocene—Helvetian : Egypt, east side of Wadi Jiaffra, north-east of Caravanserai No. 8, on road from Cairo to Suez ; Coll. Geol. Surv. Egypt, No. 644. Description or Ficurus.—Pl. VIII, Fig. 4a, part of upper surface of a corallum, nat. size; Fig. 4c, side view of the same specimen, showing lamellar growth, nat. size; Fig. 4b, one corallite, x 2 diam. Ar¥rinitres.—In Duncan’s diagnosis of Stylophora he states that “the calices are rather deep,” as is the case in the type species, S. digitata (Pall.), and the characteristic forms of the genus. The two corallites of S. similis (May.-Eym.) figured as Pl. VIII, Fig. 6, are typical forms of the Hocene group of Stylophore, which agree closely with the recent species. Another series of species is, however, included in the genus which have larger corallites and raised, exsert septa. 8S. asymmetrica is the extreme form of this group, and I felt at first that it ought to be placed in a new genus. But the essential characters are those of the true Stylophora; the difference is due to the much greater size of the corallites, and to the fact that the calice appears superficial, as it is usually raised on the exsert septa. But the calice is really deep, as it occupies a depression surrounded by the raised septa; and in some corallites the septa end below the surface of the corallum. The nearest ally of this species is probably S. macrotheca, Ach.,' in which, however, the corallites are much smaller, the distance between the calicinal centres being only from 2:5 to 3mm., so that they are about a quarter of the size of those of S. asymmetrica. Another coral which presents some striking resemblances is S. subreticulata, Reuss,” a well-known Helvetian species from the Oberer Tegel of Grund. The Egyptian coral differs, however, by the greater size of the corallites, by the greater prominence of the secondary septa, and by the asymmetry of the septa. ‘The costz occur, moreover, as raised lines, whereas in S. subreticulata the exotheca is ornamented by radial series of coarse granules. From the typical Oligocene set of species, e.g., S. distans (Leym.),° 1 A. d’Achiardi, ‘‘ Cor. Koc. Fruili,’’ pt. ii: Atti Soc. tose. Sci. nat., vol. i (1875), p. 178, pl. xiv, fig. 2. _ 2 A. KE. von Reuss, ‘‘ Foss. Kor. éster.-ung. Mioc.’’: Denk. Akad. Wiss. Wien, vol. xxxi (1871), p. 250, pl. v, fig. 10; pl. vii, fig. 1; pl. xin, fig. 5. The secondary septa are shown only in pl. vii, fig. 10. 3 A. Leymerie, ‘“‘Mém. Terr. 4 Nummul. Corbiéres’’: Mém. Soc. géol. France, ser. 2, vol. i (1844), p. 358, pl. xiii, fig. 6. Also Von Reuss, ‘‘ Pal. Stud. alt. Tert. Alpen”’: Denk. Akad. Wiss. Wien, vol. xxviii (1868), p. 24, pl. ix, fig. 2. 246 Dr. J. W. Gregory—Egyptian Corals. S. conferta, Reuss,’ 8. tuberosa (Cat.),? S. annulata, Reuss,? and S. pulcherrima, Ach.,* this new species may be easily distinguished, as they have plain inter-calicular areas, and the calices surrounded by a small raised rim. 8S. confusa, Dune.,> from the Gaj Series (Miocene) of Sind, differs by its very crowded corallites. Genus ORBICELLA, Dana, 1848. ORBICELLA SCHWEINFURTHI (Felix), 1884. Heliastrea Schweinfurthi, Felix, 1884, “Kor. agypt. Tert.”: Zeit. deut. geol. Ges., vol. xxxvi, p. 449, pl. v, fig. 5. Distripution.— Middle Miocene — Helvetian: Wadi Ramlieh (Felix) ; near north side of Jebel Attaka, near Suez; Coll. Geol. Surv. Egypt, Nos. 997 and 999. Ficure.—Pl. IX, Fig. 3, part of a horizontal section, x 8 diam. Arrinitins.—One of the four specimens of this coral resembles Orbicella Guettardi (Defr.),® and may represent the fossil recorded from Hgypt by Fuchs’ as Heliastrea cf. Rochettana. It is certainly very similar to the figures of that species given by D’Achiardi.® Felix’s species is an ally of O. Defrancei (Hd. & H.),® but the calices are deeper. Genus PLESIASTRAIA, Edwards & Haime, 1848. PLESIASTRHA MICROCALYX (Felix), 1884. Heliastrea microcalyx, Felix, 1884: op. cit., p. 450, pl. v, fig. 4. Distrrsution. — Middle Miocene — Helvetian: Wadi Ramlieh (Felix). Between lat. 30° 16” 40” and 30° 15’ 50”, and long. 31° 54’ 40” and 32° 2’ 10”; Coll. Geol. Surv. Egypt, No. 814. Description oF Ficures.—Pl. VIII, Fig. 5a, part of upper surface of an encrusting corallum, x 2 diam.; Fig. 56, horizontal section across the same specimen, x 4 diam. Arrinities.—This coral agrees exactly in external form. with Felix’s figure, so that I feel no doubt'as to their specific identity. The coral has not the external aspect of an Orbicella, and I was 1 Von Reuss, ibid., p. 25, pl. ix, figs. 3-6. 2 T. A. Catullo, ‘‘ Terr. Sedim. Sup. Venezie’’ (1856), p. 63, pl. xiv, fig. 3; and Von Reuss, op. cit., p. 46, pl. ix, fig. 7. § Von Reuss, ‘‘ Foram. Anth. Bry. Oberburg’’: Denk. Akad. Wiss. Wien, vol. xxiii (1864), p. 12, pl. u1, figs. 1-8. 4 A. d’Achiardi, ‘‘ Cor. Eoc. Fruili,’”’ pt. iii: Atti Soc. tosc. Sci. nat., vol. i (1875), p. 176, pl. xiii, figs. 1-11. P. M. Duncan, ‘“ Foss. Cor. Sind”’: Pal. Indica, ser. xiv, pt. 1 (1880), p. 73, pl. xv, figs. 12, 13. > Duncan, ibid., p. 83, pl. xxiii, fig. 7. 6 Vide Michelin, ‘‘ Icon. Zooph.’’ (1842), p. 58, pl. xii, fig. 3. 7 Th. Fuchs, ‘“ Beitr. Kenntn. Mioc. fauna Aegypt.’’: Beitr. Geol. libysch. Wiiste, vol. iii (1883), p. 65. 8 A. d’Achiardi, ‘‘ Studio Comp. Cor. Terr. terz. Piem. e Alpi Venete’’: Annali Univ. Pisa, vol. x (1868), p. 14, pl. i, figs. 12, 13. ® Vide Von Reuss, ‘‘ Foss. Kor. éster.-ung. Mioc.’”? : Denk. Akad. Wiss. Wien, vol. xxxi (1871), p. 239, pl. ix, fig. 3; pl. x, fig. 1. Dr. J. W. Gregory—Egyptian Corals. 247 not surprised that a microscopic section showed the presence of pali, and accordingly necessitated the transference of the species to Plesiastrea. The figure of the section also illustrates the nature of the exotheca. The species is very closely allied to Plesiastrea Romettensis, Seg.’ Genus SOLENASTRAA, Edwards & Haime, 1848. SoLenastR#A Tvronensis (Michelin), 1847. Astrea Turonensis, Michelin, 1847: ‘Icon. Zooph.,” p. 312, pl. Ixxv, figs. 1, 2. Solenastrea Turonensis, Edwards & Haime, 1857: “Hist. nat. Cor.,” vol. 11, p. 498. Distripution. — Miocene — Helvetian: Turin, ‘Touraine, ete. ; Egypt—Jebel Geneffe, near Suez (fide Fuchs); Camp No. 20, between Cairo and Suez; Coll. Geol. Surv. Egypt, Nos. 356, 372 ; and Jebel Owebid, No. 971. Descrietion or Ficure.— Pl. IX, Fig. 4, horizontal section across some corallites, x 3 diam. Remarxs.—The collection includes a series of massive specimens of a coral, which has the long, narrow, crowded corallites of typical Solenastree. It is only exceptionally that any septa are preserved, a fact which suggests their possible cribriform nature. That the septa are not cribriform may be proved by lateral examination of the septa, which, however, is seldom possible. It is shown by the section on Pl. IX, Fig. 4. The figure does not show the intense secondary mineralogical changes that have occurred in the substance of the corallum. The coral has all the specific characters of Solenastrea Turonensis (Mich.). Locard? has described a nearly allied Corsican coral as Solenastrea Peroni, which is said to differ from S. Turonensis by the smaller size of the corallites (diameter 1-5 mm. instead of 2 mm.) and the less developed columella. The former difference is slight, and the latter may be an accident of preservation, as in Cyphastrea septa and columella are so easily removed; while Klunzinger’s figures of the Red Sea species shows that the columella varies greatly in different corallites of the same corallum.. Thus, his fizure® of C. chalcidicum, Forsk., has no trace of columella in many corallites, whereas it is fairly well developed in a few. The Egyptian specimens agree with the typical forms of S. Turonensis in the diameter of the corallites and with S. Peroni in the development of the columella. 1 G. Seguenza, ‘‘ Cor. foss. terz. Messina,”’ pt. ii: Mem. R. Accad. Sci. Torino, ser. 2, vol. xxi (1864), p. 111, pl. xiii, fig. 3. For better figures see Von Reuss, “Foss. Kor. éster.-ung. Mioc.’?: Denk. Akad. Wiss. Wien, vol. xxxi (1871), p. 244, pl. xvi, fig. 2. 2 A. Locard, “‘ Descr. Faune Terr. Tert. Moy. Corse’’ (1877), p. 219, pl. vil, figs. 5-7. ChE: Klunzinger, op. cit., pt. ii (1879), pl. v, fig. 8. Giese) Dr. J. W. Gregory—Egyptian Corals. Among recent Red Sea species it is most allied to C. chalcidicum, Forsk., which Klunzinger’s figures! do not show to have cribritorm septa. S. Turonensis has been doubtfully recorded in the Egyptian Miocene by Fuchs.? GENUS INDET. The collection includes two blocks of a Miocene coral (Coll. Geol. Surv. Egypt, No. 998), which are the internal casts of a large flat-topped massive corallum. They are labelled Isastrea, but are insufficiently preserved for identification. The corallites are circular, separated by exotheca, the walls appear to have been solid, the septa are long and thin, and there is no columella. This series of characters suggest the genus Arecis. The specimers were collected at lat. 80° 12’ 20”, long. 82° 24’ 30”. III. EOCENE. Genus CHILOSMILIA, Edwards & Haime, 1850, Ca tosminiA MiILNERI, nov. Dracnosis. Corallum free, tapering below to a sharp point; laterally com- pressed, so that the transverse section is elliptical. The axis is straight or slightly curved. Calice shallow. Septa very jagged; five complete cycles, the members of which are very unequal in size; the primary and secondary septa are thick near the periphery; septa of higher orders thin and short. Septa slightly exsert. Acial space very large. Hpitheca irregular; when present it consists of a thin layer, horizontally wrinkled. DIMENSIONS. mm. mm. mm. mm. Height SPI Pel eae ed eg aS erry Wik Ae) Diameter: pmayore en Suey san yy Aton .a kl .o mn eeemmnemie Tame ters eM OTe eel ee ene OL eee calles) Distrisution.— Lower Eocene—Libyan Series: Dungul Wells (lat. 23° 80’, long. 31° 21’), Upper Egypt ; Coll. Geol. Surv. Egypt, No. 265. Description or Ficgures.— Pl. VIII, Figs. 1, 2, and 3, three specimens seen from the side (Figs. la, 2a, and 3a) and in transverse section (Figs. 1b, 2b, and 3b) ; nat. size. AFFINITIES.—The simple corallum, the absence of endotheca, of pali, and of columella, the large axial space, the broad interseptal loculi, and jagged septa, are the characters which together * C. B. Klunzinger, op. cit., pt. ii (1879), p. 53, pl. v, fig. 8; pl. x, fig. 11. 2 Fuchs, op. cit., p. 64. Dr. J. W. Gregory—Egyptian Corals. — 249 necessitate the reference of this species to the genus Celosmilia. The only other genus that needs consideration is Smilotrochus, which has simpler and more crowded septa and narrower inter- septal loculi. The nearest allied species is Celosmilia Fawast (Hid. & H.),’ from the Maastrichtian of Ciply, which has a peduncle, although, as the authors of the species remark, the coral probably becomes free when mature. But the Belgian coral is much taller, and narrower; the height is 40mm. and its diameter 20mm., whereas the Hgyptian species is smaller, lower, and proportionately broader. Ceelosmilia elliptica, Reuss,” from the Oligocene of Castelgomberto, is also an allied form, but has longer, more equal septa, and a small axial space. It is also pedunculate. Another similar species was described as Smilotrochus cristatus, Felix,? from San Giovanni Harione, but in that species also the septa are less unequal, those of the last orders being much longer than in Celosmilia Milner. The species is named after the distinguished former Financial Adviser to the Khedive, by whose management of the Hgyptian finances the Geological Survey of the country has been rendered possible. Genus STYLOPHORA, Schweigger, 1819. SryLopHora srtmriLis (Mayer-Hymar), 1883. Astrohelia similis, Mayer-Eymar, 1883, “ Verst. tert. Birket - el - Qurtin”: Beitr. libysch. Wiiste, vol. i, pt. 2, p. 73, pl. xxii, fig. 2. Disrripution.—Upper Hocene: Fayum, in Lake Birket-el-Qurun (Mayer-Eymar), and Coll. Geol. Surv. Egypt, No. 619. Desorrerion oF Fieure.—PI. VIII, Fig. 6, two corallites showing the columella, x 3 diam. AFFINITIES.— The occurrence of a well-developed columella in this coral is alone sufficient to necessitate its removal from Astrohelia. The species is a member of Duncan’s alliance the Stylophoroida, and of the genus Stylophora, of which its nearest ally is perhaps S. distans (Leym.).4 Comparison of the figure here given of two corallites with Leymerie’s figures of S. distans shows the resemblance between them ; the corallum in the latter is granulate, but so it may also have been in the Egyptian species. The specimens are not well preserved, having been polished and worn by sand erosion. Professor Mayer-Eymav’s figures do not show the columella, which is not often seen in the five specimens in the Geological Survey Collection. T'wo 1 Parasmilia Fawasi, Edwards & Haime, ‘‘ Mon. Astr.’?: Ann. Sci. nat., Zool., ser. 3, vol. x (1849), p. 245. Edwards & Haime, ‘“‘ Hist. nat. Cor.,’’ vol. ii, p. 177. 2 A. KE. von Reuss, ‘‘ Pal. Stud. alt. Tert. Alpen’?: Denk. Akad. Wiss. Wien, vol, xxviii (1868), p. 140, pl. i, fig..d. 3 J. Felix, ‘“‘ Krit. Stud. tert. Kor. Vicentin’’?: Zeit. deut. geol. Gesell., vol. xxxvii (1884), p. 382, pl. xvii, figs. 1-3. 4 A. Leymerie, ‘‘ Mém. Terr. 4 Nummul. Corbiéres’’: Mém. Soc. géol. France, ser. 2, vol. 1 (1844), p. 388, pl. xiii, fig. 6. 250 Dr. J. W. Gregory—Egyptian Corals. corallites with the columella are shown on Pl. VIII, Fig. 6. The corallum occurs in cylindrical or flat branches. Genus LITHARAVA, Edwards & Haime, 1849. LitHAR#A EPITHECATA, Duncan, 1880.! DistriputTion.—Cardita Beaumonti Series: Sind. Lower Hocene —Libyan Series: a little south of Silsila, on the Nile (lat. 20° 40’), Upper Egypt: Coll. Geol. Surv. Egypt, Nos. 165, 176, 183 ; Dungul Wells (lat. 23° 30’, long. 31° 20’), Upper Egypt; same coll., No. 306. Description oF Ficures.—Pl. VIII, Fig. 7, part of the surface of a young corallum with deep calices (No. 183), x 2 diam. ; Pl. IX, Fig. 6, part of a hemispherical corallum (No. 806), x 2 diam. Remarks.—The coral is represented in the Egyptian collection by two forms—one with a low, flat, broad corallum, like the type of the species ; and the other, hemispherical, like Duncan’s var. hemispherica. I do not see how these Egyptian corals can be specifically separated from the Sind specimens, and so describe them as a geographical variety. Litharea epithecata is closely allied to L. rudis, Reuss,” but the septa are stouter and stronger than in that Oligocene form, which has been recorded by Felix from the Wadi Ramlieh in Egypt. IV. CRETACEOUS.’ Genus PHYLLOCCINIA, Edwards & Haime, 1848. Puytiocania Toucast, De Fromentel, 1884. “Pal. Franc. Terr. Cret.,”” Zooph., p. 549, pl. cliii. Var. ANGypTiaca. Cuaracters.—This coral differs from the typical form of the species by the smaller size of the corallites, which are, moreover, somewhat more crowded. In other respects the corallum agrees precisely with the specimen figured by De Fromentel : the costa are not always alternately unequal, but then they do not appear to be so in the original figure. DIMENSIONS. Type. Var. Zgyptiaca. Height of corallum eye = 42 mm. Diameter of corallum ae Ses = 61 x 87 mm. Average diameter of corallite ... 8 mm. 4—5 mm. Average distance of calicinal centres 10 mm. 6-6 mm. Septa ak is sah ... 8 complete cycles. 38 complete cycles. 1 «¢ Foss. Cor. Sind’’: Pal. Indica, ser. xiv, pt. 1, p. 23, pl. il. 2 Von Reuss, ‘Pal. Stud. alt. Tert. Alpen’’?: Denk. Akad. Wiss. Wien, vol. xxix (1869), p. 251, pl. xxvii, fig. 2. 8 A description of the Cretaceous rocks of Abu Roasch, with a diagrammatic map of the fault system in the district, has been given by J. Walther, ‘‘ L’ Apparition de la Craie aux Environs des Pyramides’’: Bull. Inst. Egypt, ser. 2, No. 8 (1887), pp. 8-13; 2 pls. Dr. J. W. Gregory—Egyptian Corals. 251 Disrripution.— Turonian: Bausset, France (De Fromentel) ; Abu Roasch, Egypt (Brit. Mus. Coll., R. 336, and Coll. Geol. Surv. Egypt, No. 53). Fieurrs.— Pl. IX, Fig. la, corallum from above, 2 nat. size; Fig. 1b, part of upper surface of corallum, x 2 diam.; Fig. le, some corallites seen in horizontal section, x 3 diam. Fig. 2, part of hori- zontal section across another specimen, x 2 diam. Remarks.—The specimen used as the type of this variety was presented to the British Museum by W. M. Newton, Esq. It is well preserved, and shows the upper surface of the corallum. A weathered specimen sent by the Egyptian Geological Survey proves to be the same species; the external surface has been destroyed, and only transverse sections show sufficient of the septa for determination. DESCRIPTION OF PLATE VIII. Fics. 1-3. Celosmilia Milneri, nov. Libyan Series. Three specimens seen from the side (Figs. 1a, 2a, and 3) and in transverse section (Figs. 1, 20, and 30) ; nat. size. Coll. Geol. Surv. Egypt, No. 268. Fic. 4. Stylophora asymmetrica, nov. Helvetian: east side of Wadi Jiaffra, on road from Cairo to Suez; Coll. Geol. Surv. Egypt, No. 644. Fig. 4a, part of upper surface of corallum, nat. size; Fig. 4c, view of vertical section across the same specimen, nat. size; Fig. 44, one corallite of the same specimen, seen from above, x 2 diam. Fie. 5. Plesiastrea microcalyx (Felix). Helvetian: Coll. Geol. Surv. Egypt, No. 814. Fig. 5a, part of upper surface of corallum, x 2 diam. ; Fig. 4d, part of a horizontal section across the same specimen, x 4 diam. Fic. 6. Stylophora similis (Mayer-Eymar). Upper Eocene: Fayum ; Coll. Geol. Surv. Egypt, No. 619. x 3 diam. Fie. 7. Litharea epithecata, Dunc. Libyan Series: Coll. Geol. Surv. Egypt, No. 183. Part of surface of a young corallum, showing deep calices, x 2 diam. “DESCRIPTION OF PLATE IX. Fies. 1 and 2. Phyllocenia Toucasi, De From., var. gyptiaca, nov. var. Turonian: Abu Roasch, near Gizeh. Fig. la, upper view of the corallum in the British Museum (R. 3,486), 3 nat. size; Fig. 16, part of the upper surface of the same, x 2 diam.; Fig. le, a horizontal section across the same, x 3 diam. Fig. 2, part of a horizontal section across a specimen in the Coll. Geol. Surv. Egypt, No. 53; x 2 diam. Fie. 3. Orbicella Schweinfurthi (Felix). Helvetian: Coll. Geol. Surv. Egypt, No. 997. Part of a horizontal section, x 3 diam. Fic. 4. Solenastrea Turonensis (Mich.). Helvetian: Coll. Geol. Surv. Egypt, No. 856. Part of horizontal section across several corallites, x 3 diam. Fic. 5. Fungia patella (Ell. & Sol.), var. lobulata, Kinz. Pleistocene: Egypt. Coll. Brit. Mus., No. R. 1,308: a view of part of the base, showing the scar ot the anthoagathus and the low obtuse spines on the costie, x 2 diam. Fie. 6. Litharea epithecata, Dunc. - Libyan Series: Coll. Geol. Surv. Egypt, No. 306. Part of the surface of a hemispherical corallum, x 2 diam. 252 Prof. G. A. J. Cole—Meshwork-structures in Rock Sections. II. — On MeshworK-STRUCTURES OBSERVABLE IN MICROSCOPIC Sections or Rocks. By Grenvitte A. J. Couz, M.R.I.A., F.G.S., Professor of Geology in the Royal College of Science for Ireland. HIS note deals with a very simple matter, which is perhaps familiar to many workers with the microscope. I believe, however, that it is not referred to in ordinary text-books, and a word or two in reference to it may be useful. From time to time, meshwork-structures have been described, either in the felted groundmasses of igneous rocks or in the pro- ducts of the decay of ferromagnesian minerals; and it is frequently remarked that a rectangular arrangement of the constituents of the mesh is clearly brought out when the section is examined between crossed nicols. One of the most beautiful experiments to illustrate the separation of materials in a crystalline form from a state of fusion is to receive a drop of “candle-grease” from an ordinary commercial candle upon a microscopic slip. Place a circular cover-glass upon it, heat until the material is well fused, and lay it beneath a power magnifying some 100 diameters and between crossed nicols. If the instrument has been previously focussed for a glass slip of the right thickness, no stage of the process of crystallisation will be lost. At first, as cooling proceeds, tiny specks emerge from the dark ground, like stars in an evolving universe. Gradually a delicate meshwork of fine and somewhat wavy rods spreads inwards from the cooling outer circle of the cover-glass. These rods rapidly thicken, while their interstices finally become filled up. But the meshwork effect is still perceptible, and a rectangular arrangement of the crossing fibres is strikingly apparent. On repetition of the experiment, it may appear surprising that the rectangular mesh extends regularly across the slide, as if some polarity existed between the minute crosses of which it is com- posed. On still further repetition, it will be plain that the two series of fibres always lie at 45° to the diagonals of the crossed nicols. On rotating the stage, the meshwork does not rotate; that is, new fibres come into the positions of the former ones, and henlies into the same positions of prominence between crossed nicols. The secret is, of course, that the crystals of stearic acid are in these positions in a state of maximum illumination, while those lying in other positions have a much feebler effect upon the eye, or may even be totally extinguished. Hven if the crystals of such an aggregate have oblique extinction, in every radiating or hap-hazard group there are likely to be four crystals which are at 45° to their ~ positions of extinction; these will impress themselves upon the eye, and a cross will be the result, though its components will not have their longer axes at 45° to the diagonals of the nicols. The effect is far more noticeable where, owing to the thickness of the section, - or to the strength of the double refraction of the material, the interference-colours are of a high order. J have seen no more striking example than in a schist with irregularly scattered plates Prof. G. A. J. Cole—Meshwork-structures in Rock Sections. 253 of muscovite, which I recently received for examination from the Geological Survey of the United Kingdom. The cross-sections of the mica, coloured in pinks and greens between crossed nicols, stand out in two distinct series perpendicular to one another, so as to suggest a remarkable double foliation. On rotation of the stage, however, all chance of misconception was removed. It would be unwise to suggest that this or that rectangular mesh, described by various authors, may be a structure visible only between crossed nicols, and with no existence in reality. But it is easy to extend the observation to the mesh-structure of decomposing olivine, and to dispose of some of the difficulties as to the presence or absence of rectangularly arranged fibres in particular examples. I am indebted to Miss C. A. Raisin, B.Sc., for the loan of several sections of serpentine from the Rauenthal, for comparison with other serpentines in my own collection; and the former have proved of special service. While fully agreeing with Miss Raisin * and Professor Bonney? as to the former existence of olivine in the Rauenthal rock, I would not lay great stress upon the rectangular appearances seen in the meshwork of this or other serpentines.° Where the mesh-structure is on a coarser scale, or on using a higher power, rectangular mesh-structures are rarely seen, since the eye does not readily take in the requisite number of illuminated bars at the same time; where, however, the structure is finer—i.e., where the original cracks of the olivine were closer together—a rectangular effect is readily produced, by the prominence of the doubly re- fracting decomposition-products lying along those cracks or portions of cracks that happen to be perpendicular to one another. I cannot help thinking that von Drasche’s* “deutliches quad- ratisches Netzwerk” in some parts of the “ serpentine-like rock” of Windisch-Matrey may have been quite local, or even due to accidents of observation, especially as the author states that the fibres in most parts of the rock intersect at very various angles. The rectangular effect is well shown in his plate, fig. 2; and prominence was given toa similar arrangement by Hussak* during his investigation of the antigorite-serpentine of Sprechenstein, near Sterzing in Tyrol. This rock was photographed by Cohen® in the same year, from one of Hussak’s specimens, between crossed nicols, and the figure is still better known from its occurrence in Rosenbusch’s “ Massige Gesteine.” In his description of the plate, Rosenbusch uses for the arrangement the term “ Balkenstructur,” which is adopted also by Zirkel.’ Cathrein* also comments on 1 “The Nature and Origin of the Rauenthal Serpentine’’: Quart. Journ. Geol. Soc., vol. liti (1897), p. 255. 2 «Note on Specimens of the Rauenthal Serpentine’’: Grou. MaG., 1887, p. 68. 3 See Miss Raisin, op. cit., p. 263. 4 «Ueber Serpentine und serpentinabnliche Gesteine,’’ Tscherm. Mitth., 1871, p.d (Jahrb. d. kk. geol. Reichsanstalt, Bd. xxi). > << Ueber einige alpine Serpentine,’’ Tscherm. Mitth., 1883, p. 70. ‘« Sammlung von Mikrophotographien,”’ pl. Ixv. ‘Lehrbuch d. Petrographie,’’ 2te. Auflage, Bd. ii (1894), p. 384. *¢ Beitriige zur Petrogr. Tirols’’? ; Neues Jahrb. fiir Min., 1887, Bd. i, p. 152. ona on 254 Prof. G. A. J. Cole—Meshwork-structures in Rock Sections. a ‘“ Balkennetz,” and agrees with Hussak on its significance in indicating the pyroxenic origin of certain serpentines. F. Becke,! as is now well known, has diminished the importance of Hussak’s suggestion by indicating similar structures in an antigorite-serpentine derived from a true olivine- rock; and he regards the antigorite plates as developed along the cleavages of the original olivine grains. This is the view taken by Miss Raisin in dealing with the rectangular structures of serpentine; while Professor Bonney, with much probability, regards the irregularity of the mesh-structure ordinarily seen as due to the imperfect character of the cleavages in olivine. In 1891 I wrote”: “'These needles, picked out by the use of the polariscope, are so frequently at or nearly at right angles to one another as to suggest their development along the cleavage- planes of the mineral that has been pseudomorphosed. It is often stated that the serpentine in such cases has been derived from pyroxene; but the structure is extremely common in company witb others referred as certainly to olivine.” Becke’s paper on the Stubachthal has fully confirmed the latter statement ; but my present note is intended to suggest that a true rectangular meshwork, con- tinuous throughout the whole of an olivine grain, is not so frequent an occurrence as might at first appear. In the first place, the more brightly illuminated part of the cross-section of a curving “anti- gorite” or other plate may catch the eye and give a fictitious © appearance of regularity. In the second place, a second rectangular meshwork may sometimes appear during rotation within the grain that is being observed, the former one being now extinguished ; and we thus see that several systems of cracks, with corresponding alteration-films, occur, and that these cracks are picked out in pairs by the use of polarised light. No one can deny that olivine is often broken up into approximately rectangular blocks, even in the fresh state; for the larger crystals observable in many basalts show this character when examined with the lens. Consequently, a rudely rectangular structure is common in the products of alteration. But I believe that its regularity is easily liable to be exaggerated ; and the same consideration becomes far more important when extended _to sections of metamorphic rocks, containing tufted chlorites, micas, and so forth, lying in all directions through the mass. In conclusion, the reality of the optical effect above described cannot be more happily demonstrated than in the photographs accompanying Mr. Arnold-Bemrose’s paper’ “On a Quartz-Rock in the Carboniferous Limestone of Derbyshire.”’ The irregularly-lying quartz needles have been photographed in section between erossed nicols ; and a rectangular effect, which is just apparent in fig. 2, becomes markedly so in the more fine-grained material shown in fig. 3. 1 «< Olivinfels und Antigorit-Serpentin aus dem Stubachthal,’’ Tscherm. Mitth., Bd. xiv (1895), p. 275. 2 « Aids in Practical Geology,”’ p. 164. The objects here called ‘‘ needles”’ are — the cross-sections of the little plates developed along the ounalss. 3 Quart. Journ. Geol. Soc., vol. liv (1898), pl. xii. H. Stanley Jevons— Scale of Rock Texture. 255 I1J.—A Numericaut Scare or Texture For Rocks. By H. Sranuey Jevons, B.A. HEN reading through descriptions of hand-specimens of igneous rocks I have often found a difficulty in forming an exact mental picture of the appearance of the rocks because of the very meagre information usually given as to the coarseness or fineness of their texture. The following simple method would, T believe, to a great extent obviate the difficulty now experienced in giving such information. Since the degree of texture of a rock depends on the average volume of its constituent crystals, the theoretically correct method of expressing it is by stating the latter in some standard measure. The determination of this average volume is, however, practically impossible, so we fall back on the next best method for its expression, that of measuring the average area of the individual crystals exposed on any surface of the rock. One way of doing this is by counting the number of crystals in a given area, but it is a very cumbrous process even with the best appliances I could devise. The method to be described consists in directly measuring the length of a number of crystals and calculating their average length. Its fundamental idea is the average area of the crystals, but this is expressed by means of their average linear dimensions, so that the figures, though originally lengths of crystals, are primarily symbols for their areas, a fact which it is important to bear in mind when a crystal of irregular outline is being measured. They are thus not proportional to the areas they represent, but to their square roots. As it is desirable to have a conventional usage on such points, I have chosen the length as the dimension for measurement, though theoretically any other would have done, and the millimetre as the unit in which it is expressed, because of its convenient size. As the same unit will probably be used by all, it will be unnecessary to mention it each time, 3, for instance, being understood to mean 8mm. The only apparatus required is a small scale, preferably of ivory, about eight centimetres long, divided into millimetres throughout and into half-millimetres for two centimetres from both ends.’ To measure the degree of texture with this, one first studies the surface of the hand-specimen, fixing with the eye on several crystals which appear to be of about the average size, and then one measures these to the number of about a dozen, taking the average. If the crystals are oblong the diagonal should be measured, if oval the greatest diameter (when lath-shaped the fact must be mentioned) ; but if they are very ragged one must simply measure the conspicuous parts, for it is the size of these, after all, which gives the rock its appearance of a coarse or fine texture. Some examples later on will perhaps render these directions clearer. The size of the individual erystals is fairly constant in some rocks, but in most the majority of the crystals will be of about the same size, while the rest will vary 1 Such a scale may be had of Messrs. Stanley & Son, Great Turnstile, London. 256 H. Stanley Jevons—Scale of Rock Texture. between certain higher and lower limits. In this latter case a state- ment of the general average size will still give a very good idea of the appearance of the rock, but for the sake of accuracy it would be well also to state the limits. As examples I may quote the following readings I have taken from various hand-specimens: Carrock Fell gabbro, 8; minette from Sale Fell, 1:5; Shap granite, 3 to 4, with porphyritic crystals, 25; Buttermere granophyre, 2; the tonalite of Monte Tonale, 4; a granite from Ben Nevis, 2:5, with interstitial matter about 0-3, and porphyritic crystals up to 7. The principle and method are equally applicable to microcrystalline rocks if one uses a micrometer scale in the microscope and reads the lengths of the average crystals in fractions of a millimetre. For instance, a specimen of the nosean-phonolite of the Wolf Rock, Plymouth, is in texture 0-084; with porphyritic crystals, 1:0. Perhaps it may be interesting by way of illustration to give the measurements by which the size of the porphyritic crystals was determined in this case. They are 23, 32, 60, 26, 40, 80, 40, 40, 28, 90, 40 and 60, mean 47. Since twelve divisions of the scale equal '254mm., the average length of the crystals measured is :996, say Imm. That there isa considerable difference between the maximum and minimum lengths must be admitted (a rather greater one here than usual, I think), but still there is a general average size, which the eye can get hold of and distinguish easily from one a little — higher or a little lower. As another example I may mention a biotite-olivine-dolerite from Kintellan, Argyleshire, which is in the groundmass °89 ; porphyritic constituents 2-03. The following measurements which J have made of some of the figures in Teall’s “ British Petrography” may be of service as a kind of criterion by which any person may see whether he is measuring in the way I have explained. The results quoted are the direct measurements, as I have not troubled to reduce for the magnification. Plate xxv, fig. 2, and pl. xxvii, fig. 1, are both easy to measure, and give 15 and 16 respectively. PI. viii, fig. 1 is not so easy, because many of the crystals are very ragged, but if each large patch of viridite be taken as representing one crystal we get the figure 14, or taking the magnetite separately (at 8), we have for the remainder 16. As an instance of how to measure a ragged crystal I will take the brown hornblende in the lower half of the figure. From the -bottom right-hand corner to the rounded top I make it 21, and I neglect the ragged tail which projects upwards on the right. This procedure may seem arbitrary, but it is really necessary, because otherwise such crystals would receive a value out of all proportion with their area, the quantity I have already shown that we are really endeavouring to express. In the case of ragged — crystals, therefore, discretion must be used to give a number which would probably represent the linear dimensions of a crystal of the same area but of regular outline. In pl. xii, fig. 2, the constituents must be mentioned separately, thus—porphyritic crystals (only one in the figure), 23 ; lath-shaped felspars, 8; augites, 3-5; iron-ores, 1. One of the most difficult is Sir H. H. Howorth—Surface Geology of N. Europe. 257 pl. xix, fig. 1, whose structure is that shown macroscopically by many gabbros. It is impossible in this case to separate out a number of. individual crystals and measure them, so one must scan the picture until one has an idea of the average apparent size of the crystals, fix upon two or three well-defined ones which seem to express this, and measure them. The crystals I fixed upon when measuring this figure were a plagioclase just above the centre, marked “10” in the key, and a pyroxene to the low left, marked “7.” These measure 19 and 14 respectively in greatest diameter, so that one might quote 16 or 17 as a rough average value. It must always be understood that with a rock of this structure the number given does not represent an actual measurement of crystals, but is only a measure of the general impression the eye forms of its texture, so that it cannot be very definite. The ophitic structure usually involves the quotation of at least three numbers, for the ophitic plates, the included granules, and the interstitial matter respectively. With regard to the time taken by these measurements, I may say that a hand-specimen takes me about three minutes and a slide about five. The most encouraging feature in the method is that the eye can at a glance distinguish between rocks, say, of texture 15 and 2, though by the method now in use one could only describe them both as medium-grained. I think it very likely that a little practice will enable one to give roughly the degree of texture of a rock without any measurement at all, as, for instance, to say, “‘ Texture granitic, from 2 to 25,” almost at a glance, though it would of course usually be desirable to check the statement by measurement. It is almost needless to add that the method is applicable to sedimentary rocks equally with those of igneous origin. In conclusion, I may say that several of my friends, among them Professor Bonney and Miss Raisin, have kindly measured some specimens which I placed before them. The coarse-grained rocks presented some difficulties, which led to their not giving quite concordant figures on the first attempt, but the results were on the whole distinctly encouraging, especially among the finer-grained rocks. J venture, therefore, to bring this idea before the notice of petrologists, because, although it does not entirely do away with the personal element in the description of the texture of rocks, it has at least the merit of greatly reducing it, and of so rendering comparable the descriptions of different authors. TV.—Tue Surrace Guotocy or THE NortH oF Europ, As ILLUS- TRATED BY THE ASAR OR Osar oF SCANDINAVIA AND FINLAND. By Sir Henry H. Howorrn, K:C.1.E., M-P., I RESe kee Gres (Concluded from the May Number, page 206.) i us next turn to the postulated subglacial rivers. How can we conceive of tunnels of ice 100 miles long running in one direction, 300 feet high, and only 20 or 80 paces wide? The difficulty about the provenance of the stones, again, is equally great DECADE IVY.—VOL. Y.—WNO. VI. ea ae ly! 258 Sir H. H. Howorth—Surface Geology of N. Europe. or even greater, and more insurmountable in such a case than it would be in the case already cited. Those parts of Sweden whence the stones in question were derived are so comparatively low that we cannot conceive an ice-sheet existing on the scale postulated by the glacialists which did not at the same time bury all such rocky surfaces fathoms deep under ice. We have already, in many ways, criticized the transcendental notion involved in so-called ‘“‘ground moraines,” and the mechanical pro- cess which the wilder American geologists euphoniously describe as “plucking.” ‘“ Plucking” is the process by which ice, under a pressure of many tons to the square inch and moving so slowly that the movement would be virtually inappreciable in the nether layers of the ice-sheet, is supposed to have had the capacity of breaking up its own bed and performing feats of quite superlative dentistry. This view, which I believe to be utterly fantastic, and which has never been supported by any mechanical argument or by anything better than an obiter dictum, is the only refuge for the believers in ground moraines as the explanation of the Swedish asar. But this plucking proceeding is not all that is required. Granting that we may indulge ourselves in a plucking theory, in order to pluck up stones the ice must be in contact with its stony bed, and we altogether fail even to understand the process when the © ice is separated from its bed by a padding of sand or gravel or boulders. Can it continue to “pluck” through this intervening cushion, and if so, how is it to continue doing so when the sub- glacial deposit becomes 40 or 50 or a 100 yards thick? If we discard the plucking process as ridiculous, whither is the glacialist to turn ? When a stream began to flow underneath an ice-sheet, how could it possibly obtain materials from any other source to pile up a mound a hundred miles long, of uniform height, and rising a hundred yards above the level of the bed of the ice-sheet itself? It could not derive them from the rocks underlying its own bed, for these would be protected from denudation by the sand and gravel and stones already there. Suppose it were possible to get the stones (stones formed of the hardest crystalline rock), how could it roll them into absolutely rounded and curved forms? On such a bed basalt and gneiss are not easily worn into these shapes by being rolled over beds of sand and clay containing a sprinkling of stones. If it were strong enough to roll them and toss them about, the subglacial stream must have been a torrential river, and if so, as we have said, it must have scoured out the sand and brickearth completely, instead of leaving them mixed heterogeneously with the great boulders. I have referred to the difficulty of assigning continuous mounds of the same general height and breadth, and extending over great distances, to the handiwork of rivers, whose beds naturally and necessarily grow wider as they march from their source to their outfall; but in the case of the Scandinavian asar the subglacial theory presents an additional difficulty. According to the glacialists, the Scandinavian ice-sheet extended to the Carpathians and to Sir H. H. Howorth—Surface Geology of N. Europe. 259 Central Russia. How is it, then, that the asar did not continue their strange march right away to these goals? Did the subglacial rivers stop short where the various Swedish asar terminated their journey? Ifso, what became of their water? Was it frozen again ? How was this? ‘The further south we travel, the warmer must the climate have been under the same conditions, and consequently the more water must have flowed from the ice-sheet. Its drains, the subglacial rivers, must therefore have increased in volume instead of dying out, and surely when they reached the flat country of Poland and Russia must have become more and more liable to deposit materials in their beds. How is it, then, that the asar do not continue their march to Cracow? But apart from all this, let me repeat a question I have already asked, and which presents itself to a traveller who has crossed the country in a very grotesque fashion. I wonder if the champions of subglacial rivers as the depositors of the asar have ever drawn a series of contour-lines, say from Dalecarlia to Silesia, and if so, how do they propose to explain the flow of any river, whether under an ice arch or not, along such a course, not only across the undulating surface of Sweden, but across the Baltic depression ? There remains another element which we have not yet considered, namely, the large, sometimes portentously large, angular and sub- angular blocks which occur in the surface layers of the dsar, and sometimes in large numbers on their backs, the as near Gamla Upsala being a good example. Among the many boulders we noticed, there was one whose cubical contents must have been 36 yards. Similar subangular and angular blocks have occurred in the deposit containing marine shells at Upsala. How are we to explain these blocks and their occurrence where they are found, by _ any kind of fluvial action? Rivers must become desperate torrents, such as occur sometimes in the ravines of the Caucasus and the Western Himalayahs, to move such stones at all, and how could they be deposited by rivers in the midst of stratified sands with marine shells, and on the tops of the asar ? How comes it they are not found at the bottom, where the cannon-shot gravel so often occurs? When it is said they were transported by ice-rafts, how could they get on to the backs of the ice-rafts? If frozen to their under surface, the difficulty is still greater, for torrential rivers do not freeze into solid masses, nor does their ice-covering become attached to boulders which may be lying on their beds. So far as I know, rivers in Scandinavia do not now carry about and deposit such stones, except when there may be an occasional collapse in their banks; and if the glacial rivers derived them from dis- integrated banks, it only removes the difficulty of their explanation one step further back. But those who appeal to ice in this fashion forget the relative age generally assigned to the surface beds of the asar. The great majority of geologists are emphatic about the surface beds of the dsar containing marine shells being Post-Glacial. If so, then we have a double crux, for not only have we to explain the existence of gigantic erratics far away from their parent beds, 260 Sir H. H. Howorth—Surface Geology of N. Europe. but to explain them and their portage when anything but a glacial climate is testified to by the mollusca occurring with them. It seems, therefore, impossible to appeal to ordinary rivers in order to explain these angular blocks ; much more so is it difficult to account for their portage by subglacial or supraglacial rivers. In neither case do such rivers carry ice-rafts. Nor can we see how ice-rafts could arise in either of them. Ice-rafts are the broken pieces of ice which once covered subaerial rivers. The only ice which covers subglacial rivers is the tunnel of ice through which they flow, while supraglacial rivers do not freeze on their surface, but cease to exist entirely in winter, for they are the result of the melting of the surface of the glaciers and nothing more. In every way we view the fluviatile theory of the origin of the asar it seems to collapse when analyzed, and if I could be astonished at anything which the glacial geologists choose to formulate I should be greatly surprised at its continued existence in their textbooks. The time is assuredly coming when the reputations which have been built up on such science will as assuredly collapse. No wonder a desperate struggle is made to maintain them in some quarters, and a portentous silence prevails in others. Putting aside the fluviatile theory, whither are we to turn for an explanation of the asar but to the primitive theory of all; the | one which commended itself to the earliest Swedish geologists, namely, that they are in some way or other the result of the action of the sea during a period of submergence. Thus Swedenborg urges that the existence of a former widespread ocean is proved by the mixture of substances in the asar of sand and gravel, of clay, and large masses of rock and boulders. He urges further that the polished and triturated appearance of the stones in them was the work of the sea, and the slope of the ridges he thinks proves that they were thrown up by the sea into great accumulations, and so formed into lengthened ridges. He argues that the fact of the ridges running north and south shows that the same winds prevailed in Diluvian times as do now, and he appeals to the principle of hydraulics to show that the sea could have done this kind of work. Robert, writing as far back as 1886, says: “Les collines de sable du N., ou dsars comme on les appelle vulgairement, ont été formées au sein des eaux de Ja mer par leffet des courants, phénoméne encore en action.” The sea in its normal attitude was appealed to to explain the asar by two other acute, later writers, namely, Ch. Martins and Robert Chambers. The former, an extreme champion of the Glacial theory, says: “The asar form one of the numerous proofs of the immersion and emergence of the Scandinavian surface. . . . . The dasar were the work of the sea during the time of the Scandinavian immersion. They are veritable dunes (the Revler of the Jutland coast), with a cross- bedding in their stratification, formed by the waves which traversed these ramparts and there deposited the pebbles and sand which it had removed from the bottom of the sea. The pebbles in the asar are never striated. If they ever had any striz these have been Sir H. H. Howorth—Surface Geology of N. Europe. 261 removed by their being rubbed down by the sea,” etc. (Bull. Geol. Soc. France, 1846, p. 97.) R. Chambers, writing in 1850, after speaking of the angular drift of Sweden as the result of glacial action, continues: ‘This rubbish has afterwards been under the sea, which, detaching certain portions, has worked the stones into round forms, separated the sand and clay, and left the whole in a new arrangement, namely, that of terraces with long branching ridges or banks.” These ridges he connects with the Irish eskers and the Scotch kames, but says they are specially characteristic of Sweden, where they extend for hundreds of miles without any regard to the interruption of lakes or rivers, sometimes thirty, sometimes fifty, and occasionally not much less than a hundred feet in height above the base; and he attributes them to the agitations of a sea which had succeeded to the reign of the glacial influence. (‘‘Tracings in the North of Hurope,” p. 238, etc.) Hrdmann, writing in 1868, accepts the conclusions of Martins and Chambers, and speaks of the dsar as “d’anciennes jetées litorales accumulées et remaniées par la mer” (‘‘ Exposé,” etc., p. 42). This view is a good deal more rational than that which attributes the asar to the operation of rivers, subglacial or otherwise. We can hardly account for the formation of the boulders which make up so large a portion of the dsar except by the intervention of the sea. These boulders are, so far as my experience goes, quite different to river shingle. Their enormous and portentous number, their widespread distribution, the very hard-crystalline rocks out of which they have been rolled and fashioned, all testify in a most effective manner to the operations of a turbulent sea on a shallow bottom acting upon the débris of crystalline rocks, and acting for a long time. They bespeak, in fact, a period of long depression. They seem to me to be the complementary phenomenon to the polished and rounded surfaces of Scandinavia, to have been fashioned at the same time, and to have been, in fact, the main instruments in the hands of the sea in rounding and polishing these surfaces, being themselves rounded in the process. They present as few traces of ice-action as cannonballs or Beecham’s pills do. Secondly, the sands which form the so-called sand asar, and form also conspicuous beds in other asar which are nearly always, if not always, stratified and false-bedded, seem to me to be marine sands, and nothing else. I cannot in any way distinguish them from well- known barren marine sands elsewhere, and notably those of Dalecarlia, which occur there sometimes as dsar and sometimes as thick and well-stratified beds covering a wide extent of country. ‘These wide- spread stratified sands of Dalecarlia and their lessons were especially noted by Murchison. ‘In approaching Hedmora,” he says, “or ascending to‘that town, which lies about 150 or 200 feet above the River Dal Elf, the whole tract is one of undulating hilly sands aes resembling the bottom of a former sea. . . . . In approaching Sater these sands, constituting linear asar here and there united by cross bands or bars, are covered by worn boulders and gravel, and further on the asar are entirely composed of water-worn 262 Sir H. H. Howorth—Surface Geology of NV. Europe. boulders. . . . . The river banks at Sater, as at numberless places on the Dal HIf, consist of mounds of finely laminated sandy loam.” (Q.J.G.S., iii, 872.) Murchison goes on to describe the sometimes finely aan sands which are seen in following the Dal Elf through the fertile tracts of Gustafsland (id., p. 373). I have recently been spending some days in this same district, and have been deeply impressed by the same facts, and notably as they occur about Leksand and thence to Insjon. A third notable testimony to the marine origin of the asar is the presence in several cases in their upper layers of marine molluscs like those now living in the Baltic. At Upsala I collected numerous specimens of Tellina Balthica, Cardium edule, Littorina litorea, and Mytilus edulis. The last-named were much decayed and reduced to fragments. They still retained their colour, which gave a purple tinge to the clayey bed in which they lie. This kind of evidence is a very potent support to the view that the asar are, in fact, of submarine origin, and witness, as so many other facts in Scandinavia do, a recent submergence of a large part of the country. It is, nevertheless, clear that when we examine other features of the asar we cannot attribute them to the ordinary operations of the ocean, and I confess I cannot see in them, as some others have done, a kind of sea-beaches or dunes. Their shape, their internal structure, the alignment of the stones in them; the fact that they consist of a number of parallel ramparts; the further fact that their main trunks have a number of branches; their occurrence at all levels from 2,000 feet downwards; their running up and down hill and being distributed entirely independently of the contours of the country; their sometimes occurring athwart each other and sometimes as cross pieces joining two separate asars; the rounded and elliptical forms they assume when their continuity is broken : all these facts seem to be at issue with their having been beaches. On the other hand, the sea in its normal moods does not diversify its actual bed with such ramparts as these. The sea in its normal action is a great leveller and smoother of its beds into soft and curving outlines, and does not lay down upon it a succession of ramparts with steep sides and running for scores of miles in direct lines. Nevertheless, it is from the operations of the sea, not in its normal but in its abnormal moods, that the only explanation of the asar which fits in with the facts is derivable, and has long ago been derived. Playfair has a pregnant passage on this subject written long ago. ‘‘Sandbanks,” he says, “‘such as abound in the German Ocean, to whatever they owe their origin, are certainly modified, and their form determined, by the tides and currents. Without the operation of these last, banks of loose sand and mud ~ could hardly preserve their form and remain interseeted by many narrow channels. The formation of the banks on the coast of Holland, and even of the Dogger Bank itself, has been ascribed to — the meeting of tides, by which a state of tranquillity is produced in the waters, and in consequence a more copious deposition of their mud. Even the great Bank of Newfoundland seems to be Sir H. H. Howorth—Surface Geology of N. Europe. 263 determined in its extent by the action of the Gulf Stream. In the north-east the current which sets out of the Baltic has evidently determined the shape of the sandbanks opposite to the coast of Norway, and produced a circular sweep in them, of which it is im- possible to mistake the cause.” (Playfair’s “Illustrations,” pp. 417-8.) So much for an old master, who was also a champion of Huttonian methods in geology. In more recent times the same lesson has been weil and continually pressed by Mr. Kinahan in regard to the Irish eskers, which are really small forms of asar. I will quote a passage or two, which I cannot improve upon. He says: “The eskers are modifications of the banks and shoals which accumulated at the colliding and dividing of the ‘flow’ tide currents of the esker sea, similar to those that are found in the seas round Great Britain and Ireland at the present day. In the Irish Sea, in the vicinity of the Isle of Man, there i8 a meeting of the north and south ‘flow’ tide waves or a ‘head of the tide.’ Here the tidal currents meet and neutralize one another in one place, forming a mass of currentless water that simply ‘rises’ and ‘falls’ and deposits there silt and other materials. The other heads of the tide in these seas are south and east of Hngland—in the Straits of Dover and between Norfolk and Holland. But in these places there are different results, as the currents collide and pass one another for greater or less distances, and at their edges, or the junction of the different currents, long banks of gravel and shingle accumulate. It is also found that long banks of gravel and shingle may form at the dividing or splitting up of the ‘flow’ tide current. This is exemplified off the south-east coast of Ireland. From Greenore Point a main current runs northward up the Irish Sea, while secondary currents branch off into Wexford Bay; and at the junction of these currents with the main current there are long banks between Greenore and Wicklow Heads.” Again, he says: At the half tide or “awash” portions of banks, and in other shallow places where two currents collide, there are esker-like ridges; as St. Patrick’s Bridge between Kilmore and the Saltees, county of Wexford, and on the Dogger Bank, off the mouth of Wexford Harbour. No action but marine at the present day forms ridges at all like the eskers. (‘‘ Geology of Ireland,” pp. 225-230.) The asar are, in fact, very large and glorified eskers. ‘The shape of the asar, and their occurring in a parallel series of mounds, point to a further fact, namely, that the moving mass of water must have been separated into a number of more or less parallel currents, at whose colliding edges the long banks were accumulated. This feature is also at once explained when we examine the contour of the country, and it has been pointed out by Murchison with his usual insight, and been apparently overlooked by his successors. He points out how the asar in the neighbourhood of Upsala have long ridges of granitic rock running parallel to them, and he says they appear to have here assumed their linear direction in consequence of the rocky elevations on their flanks. The prevalent linear or 264 Sir H. H. Howorth—Surface Geology of N. Europe. north-and-south direction of these masses has necessarily been determined by the chief physical features of Sweden, which consist of frequent alternations of ridges of crystalline rocks and longitudinal depressions. Murchison further points out how, when we get away from these controlling ridges of rock, the asar depart from their typical form. Thus, he says, in the tract between Danemora and the little seaport of Kakholm, the asar, consisting of true rolled and sandy detritus, are frequently arranged in circular heaps of about 100 paces in diameter, each capped by coarse angular blocks. “‘ Now, the water- worn materials are, it will be observed, thus circularly grouped on the lowest elevations in the midst of small plains or flats, from one to two and three miles wide, which are devoid of those distinct longi- tudinal encasing ridges of granitic rocks whereby the osar have usually obtained their prevailing long and ridge-like character.’ In other cases, again, the asar simulate the ordinary “‘crag.and tail” formation, which, as Sefstrom urged, was the case in Sweden with most of the smaller ones. A well-known instance is that at Kinne- kulle, on Lake Wenern, which I have lately examined, and where a train of sand and boulders, after the fashion of an as, is most clearly, as Brongniart urged, the result of some watery current speeding over the land and leaving a train of débris behind it on meeting with an obstacle. All the facts, therefore, seem to concur in claiming as the efficient cause of the Swedish asar great masses of water, sometimes rushing in a series of more or less parallel currents, colliding and elbowing each other and dropping their burden along their edges, and sometimes coalescing into a more or less continuous flood. The abnormal size, the great length and height, and the portentous masses Of materials comprised in these mounds, and especially the great size of their contained boulders, necessitate our postulating that the rush of waters must have been on a corresponding scale. There still remains the question as to whether the asar were the result of the diurnal (tidal) operations of a turbulent ocean or the rapid and sudden action of a great and cataclysmic rush of water, such as we have on other grounds postulated. In regard to this question, they present some features which seem to me to be conclusive. In the first place, if they had been the result of the diurnal action of the sea, their internal structure would have been uniform. Instead of this we find that, while the great mass of the materials in most of them is arranged in heterogeneous fashion, being formed of a medley of different-sized boulders, their upper layers consist of stratified sands, finely levigated and laminated clays and brick- — earths, mixed with light shells, or they are formed entirely of sands marked by violent cross-bedding, pointing very clearly to a great flood which threw down the great mass of its burden regardless of its gravity, and ended up, as floods always do, by - depositing over the previous load the finer contents which it held in suspension in laminz and layers. The very fact of the great mass of the substance of the coarse asar being heterogeneous and Sir H. H. Howorth—Surface Geology of N. Europe. 265 unarranged shows that if thrown down by water it could not have been by a succession of efforts, which would have laid down stratified beds, but by one impulse of a most powerful and portentous character. This is again testified to by another fact, which I have not seen noticed, but to which I can vouch for from personal observation. When a section occurs in an as and the section has been slightly weathered by the wind, it will be seen that in many cases, where the materials are fine, and consist of sand or clay or fine pebbles, and lines of stratification and laminz occur in them, that these lines resemble those to which I have called attention occurring in the cliffs at Cromer. They form perfectly continuous lines of curvature ex- tending from the top to the bottom of the deposit, showing that the whole deposit has been the result of one impulse, and not of many. This was especially beautifully visible in an open section I noticed close to Omberg, in West Gothland, which I recently visited. This lamination is a great deal commoner in the as than is generally supposed. It often requires the face of the section to be slightly wind-weathered before it is disclosed, and I am convinced that it will be found pretty nearly everywhere when no large boulders occur. Wherever the rush of water was sufficiently great to carry with it the large stones, then, it would seem, it laid down its load hetero- geneously. Where the rush was less marked, and the water could only carry lighter materials, these lines of stratification were developed. . The most striking and conclusive proof, however, that these gigantic ramparts were thrown down by some rapid and portentous movement of water rather than by exceptional tidal action, is the fact so much overlooked by those who have written on the asar, namely, their running up and down hill without consideration for the lines of drainage, and this, too, in their line of march. No tide, no race, NO movement of water of a torrential character, such as we know it, in any of the oceans or seas of the world, would drive along such a great mass of water in a number of parallel currents, keeping the same lines of movement athwart hill and dale, and lay down enormous masses of heavy unsorted stones in gigantic ridges. To do this the water must have been not only enormous in quantity, but the impulse which drove it must also have been of quite a cataclysmic character. We can compare it only with the great waves of translation which followed the earthquake of Lisbon, or those which followed great earthquakes in Java some years ago, and of which another example occurred in Japan quite recently. These are the models and types to which we must turn in explaining the asar and other phenomena of the Drift. We have only to multiply the potency of the cause and the problem is explained, and this, as we have seen, the critical examination of the facts enables us to do. The sudden upheaval and breakage of the solid strata in Central Sweden over several degrees of latitude underneath a widespread sea—this is what the facts compel us to accept, and this is sufficient to solve our difficulty. 266 FE. R. Cowper Reed— Woodwardian Museum Notes. To conclude, therefore. The present evidence of the asar seems to me to completely support the view urged in previous papers from other facts and premises, namely, that Scandinavia was recently very largely submerged by the sea, which covered it for a long time, which smoothed and rounded its surface, and which rounded and smoothed its myriads of boulders; and that this sea was eventually drained and discharged by some rapid and sudden upheaval of its bed, causing a perhaps unprecedented diluvial movement. It was this rapid movement of a vast rushing sea, driven from its bed by the upheaval of that bed, which, as we saw in a former paper, accounted for many of the facts in the recent geology of Scandinavia. It alone, it seems to me, accounts for the various features presented by the Scandinavian dsar, and which bear no trace of any kind which can justify us in calling in ice in any shape to explain them. V.—Woopwarpian Musrum Nortss. A CaRBONIFEROUS Bracuiopop (Huuzrria? serpentina, De Kon.) NEW TO Brirain. By F. R. Cowper Resp, M.A., F.G.S. N rearranging the Carboniferous fossils in the Woodwardian Museum, I met with a specimen labelled Athyris, n.sp., which reminded me of the form described by De Koninck' as Terebratula serpentina. On careful examination I am convinced that it belongs to this species, and the following is a description of our specimen :— Shell subovate, terebratuliform, widest at about ofte-third its length from its anterior edge. Valves moderately convex, slightly flattened anteriorly, and devoid of sinus and fold; margin entire and regular. Ventral valve a little less deep than dorsal valve, and furnished with a slightly recurved beak truncated by a large circular foramen, bordered in front by a pair of deltidial plates. Surface of both valves ornamented with straight, radiating, very faint ribs, 60 to 70 in number, arranged in a regular close series separated by weak narrow furrows. Some of the ribs bifurcate at about half their _ length, and those near the hinge-line curve gently backwards. Shell substance finely punctate. Concentric strie of growth are distinct on both valves. Length, 25 mm.; breadth, 22mm. ; dorsi- ventral diameter, 12 mm. Our specimen was found by Mr. E. B. Tawney in the Lower Lime- stone Shale of Clifton, Gloucestershire, and the Tournai beds in which the Belgian specimens occur appear to be on the same stratigraphical horizon. The faunas of the Lower Limestone Shale of Britain and of the calcareous slates of Tournai are in many respects closely similar. De Koninck? in 1887 placed this species in the genus Acambona of White,* but the latter, in his original definition of this genus, gave the absence of a foramen in the ventral valve asa distinctive feature. Since " “Descr. des anim. foss. qui se trouvent dans le terr. carb. de la Belgique”’ (1843), p. 291, pl. xix, fig. 8. Me peeupe du Cale. carb. de la Belgique’’ (1887), vol. iv, pp. 96, 97, pl. xxii, gs. 25-81. “3 Proc. Boston Soc. Nat. Hist., vol. ix (1862), p. 27, figs. 1, 2. F. R. Cowper Reed—Large Boulder near Royston. 267 De Koninck figures and describes a foramen in the Belgian examples (with which ours agrees), Hall is inclined to consider this species as congeneric with Humetria vera (Hall) from the Kaskasia Limestone of the Lower Carboniferous Series of America. But until we know the internal structure of the species, we cannot positively decide to what genus it should be assigned. Waagen® has suggested that it may belong to his genus Uncinella, from the Productus Beds of the Salt Range of India. In the description of Retzia ? carbonaria (Dav.) from the Lower Carboniferous Shales of Skrinkle, Pembrokeshire, Davidson * mentions Terebratula serpentina, but Retzia ? carbonaria is held by Hall* to belong to the distinct genus Hustedia. VI.—Nore on a LARGE Bountper at Wimpour Hatt, Cams. By F. R. Cowrrr Ruzp, M.A., F.G.S. BOUT five-and-twenty years ago a large boulder, lying in the garden of Wimpole Hall, near Royston, was pointed out to the Rev. Osmond Fisher by the Lady Hardwicke of that period, and she informed him that it had been brought from near Old North Road Station when the hill there was lowered. As its dimensions and nature had not been determined, Mr. Fisher invited me to accompany him to Wimpole on April 22nd in order to examine it, having previously obtained permission from the present owner of the property, Lord Robartes. After a brief search the boulder was discovered lying about 50 yards north-west of the conservatory and almost concealed under a dense growth of ivy. It measures approximately 8 ft. 10in. in length, 4ft. in height, and 1 ft. 8in. in breadth, and consists of a greenish-grey tough sandstone. Mr. Fisher determined its 8.G. to be 1-91 and its weight to amount to 8 tons 2 ewt. Lithologically the rock is precisely similar to portions of the Spilsby Sandstone of Lincolnshire, and a specimen in the Woodwardian Museum from near Claxby is indistinguishable from it. By good luck a small Ammonite occurred in a fragment chipped off by the Rev. HE. Conybeare, who met us at Wimpole; and Mr. G. C. Crick, of the British Museum, who has kindly examined it for us, writes that it is “not referable to any species which has hitherto been recorded from Great Britain,” but that it ‘is closely related to Olcostephanus (Craspedites) subditus (‘Trautschold), which has been recorded from the Spilsby Sandstone of Lincolnshire (Pavlow and Lamplugh, ‘Argiles de Speeton,’ etc, p. 116, pl. xii (vi), figs. 5a, b, c).” The occurrence of many boulders in the Cambridgeshire Boulder- clay from northern sources has been noticed by many observers, and possibly some of the sandstones which are frequently found in it may come from the Lower Greensand beds of Lincolnshire, but, as far as I am aware, no block of such a size from these beds, bearing such a definite proof of its origin, has ever before been 1 «¢ Paleeont. New York,’’ vol. viii, Brachiopoda, ii (1894), pp. 118, 119, pl. li. 2 « Paleont. Ind.,’’ ser. xiii, Salt Range Fossils, vol. 1 (1883), p. 496. 3 «Brit. Foss. Brach.,’’ vol. ii, p. 219, pl. hi, fig. 3. 4 Op. cit., p. 122. 268 Notices of Memoirs—Antarctic Exploration. discovered in our area. The outcrop of its parent-bed is about 50 miles distant in a straight line from Old North Road Station. The Boulder-clay, where it was found, is said by Professor Bonney (‘‘ Camb. Geol.,” p. 49) to be 160 feet thick, as seen in the cutting and well. From the presence in the Cambridgeshire Boulder-clay of frag- ments of the Red Chalk and Carstone, and from the general invasion of the outcrops of beds to the south by the materials of beds to the north or north-east, it has been inferred that the direction of move- ment of the agent of transportation was towards the south; and the occurrence of this boulder of Spilsby Sandstone is strongly in favour of this view. But in spite of this evidence for its support it cannot be said that this theory is completely satisfactory, for it fails to explain the reason of the extremely miscellaneous character of the majority of the non-local rocks in the Boulder-clay, and the dis- tribution of the deposit in relation to the configuration of the country, whether we consider the transporting agent to have been land-ice, icebergs, or an ice-foot. INFGA RESINS) (Ezy | IW aIMEOrHEtS Facts AND ARGUMENTS IN FAVOUR OF AN ANTARCTIC HXPEDITION. N advocating “The Scientific Advantages of an Antarctic Expe- dition” before the Royal Society in February last, Dr. John Murray, F.R.8. (now Sir John Murray, K.C.B., F.R.S.), said :-— “ From a scientific point of view the advantages to be derived from a well-equipped and well-directed expedition to the Antarctic would, at the present time, be manifold. Every department of natural knowledge would be enriched by systematic observations as to the order in which phenomena coexist and follow each other, in regions of the earth’s surface about which we know very little or are wholly ignorant. It is one of the great objects of science to collect observations of the kind here indicated, and it may be safely said that without them we can never arrive at a right understanding of the phenomena by which we are surrounded, even in the habitable parts of the globe. “ Before considering the various orders of phenomena concerning which fuller information is urgently desired, it may be well to point out a fundamental topographical difference between the Arctic and Antarctic. In the northern hemisphere there is a polar sea almost completely surrounded by continental land, and continental conditions for the most part prevail. In the southern hemisphere, on the other hand, there is almost certainly a continent at the South Pole, which is completely surrounded by the ocean, and, in those latitudes, the most simple and extended oceanic conditions on the surface of the globe are encountered.” The author then proceeds to discuss the Meteorology. * Proceedings of the Royal Society, vol. xii, No. 387, pp. 424-451, Feb. 24, 1898, Notices of Memoirs—Antarctie Exploration. 269 “One of the most remarkable features in the meteorology of the globe is the low atmospheric pressure at all seasons in the southern hemisphere south of latitute 45° S8., with the accompanying strong westerly and north-westerly winds, large rain and snow fall, all round the South Polar regions. The mean pressure seems to be less than 29 inches, which is much lower than in similar latitudes in the northern hemisphere. Some meteorologists hold that this vast cyclonic system and low-pressure area continues south as far as the pole, the more southerly parts being traversed by secondary cyclones. There are, however, many indications that the extreme South Polar area iS occupied by a vast anticyclone, out of which winds blow towards the girdle of low pressure outside the ice-bound region. In support of this view it is pointed out that Ross’s barometric observations indicate a gradual rise in the pressure south of the latitude of 75° 8., and all Antarctic voyagers agree that when near the ice the majority of the winds are from the south and south- east, and bring clear weather with fall of temperature, while northerly winds bring thick fogs with rise of temperature. ag as as as as oS a “There would appear, then, to be good reasons for believing that the region of the South Pole is covered by what may be regarded practically as a great permanent anticyclone with a much wider extension in winter than in summer. It is most likely that the prevailing winds blow out from the pole all the year round towards the surrounding sea, as in the case of Greenland, but, unlike Greenland, this area is probably seldom traversed by cyclonic disturbances. * But what has been stated only shows how little real knowledge We possess concerning the atmospheric conditions of high southern latitudes. It is certain, however, that even two years’ systematic observations within these regions would be of the utmost value for the future of meteorological science.” Referring to the Antarctic ice, Dr. Murray said :— “From many points of view it would be important to learn some- thing about the condition and distribution of Antarctic sea-ice during the winter months, and especially about the position and motion of the huge table-shaped icebergs at this and other seasons of the year. These flat-topped icebergs, with a thickness of 1,200 or 1,500 feet, with their stratification and their perpendicular cliffs, which rise 150 or 200 feet above and sink 1,100 or 1,400 feet below the level of the sea, form the most striking peculiarity of the Antarctic Ocean. Their form and structure seem clearly to indicate that they were formed on an extended land surface, and have been pushed out over low-lying coasts into the sea. “Ross sailed for 300 miles along the face of a great ice-barrier from 150 to 200 feet in height, off which he obtained depths of 1,800 and 2,400 feet. This was evidently the sea-front of a great creeping glacier or ice-cap just then in the condition to give birth to the table-shaped icebergs, miles in length, which have been described by every Antarctic voyager. 270 Notices of Memoirs— Antarctic Exploration. “All Antarctic land is not, however, surrounded by such in- accessible cliffs of ice, for along the seaward faces of the great mountain ranges of Victoria Land the ice and snow which descend to the sea apparently form cliffs not higher than 10 to 20 feet, and in 1895 Kristensen and Borchgrevink landed at Cape Adare on a pebbly beach, occupied by a penguin rookery, without encountering any land-ice descending to the sea. Where a penguin rookery is situated, we may be quite sure that there is occasionally open water for a considerable portion of the year, and that consequently landing might be effected without much difficulty or delay, and further that a party, once landed, might with safety winter at such a spot, where the penguins would furnish an abundant supply of food and fuel. A properly equipped party of observers situated at a point like this on the Antarctic continent for one or two winters might carry out a most valuable series of scientific observations, make successful excursions towards the interior and bring back valuable information as to the probable thickness of the ice-cap, its temperature at different levels, its rate of accumulation, and its motions, con- cerning all which points there is much difference of opinion among scientific men.” We come then to the question—“ Is there an Antarctic continent ? It has already been stated that the form and structure of the Antarctic icebergs indicate that they were built up on, and had flowed over, an extended land surface. As these bergs are floated to the north and broken up in warmer latitudes they distribute over the floor of the ocean a large quantity of glaciated rock fragments and land detritus. These materials were dredged up by the ‘Challenger’ in considerable quantity, and they show that the rocks over which the Antarctic land-ice moved were gneisses, granites, mica-schists, quartziferous diorites, grained quartzites, sandstones, limestones, and shales. These lithological types are distinctly indicative of continental land, and there can be no doubt about their having been transported from land situated towards the South Pole. D’Urville describes rocky islets off Adélie Land composed of granite and gneiss. Wilkes found on an iceberg, near the same place, boulders of red sandstone and basalt. Borchgrevink and Bull have brought back fragments of mica-schists and other continental rocks from Cape Adare. Dr. Donald brought back from Joinville Island a piece of red jasper or chert containing Radiolaria and sponge spicules. Captain Larsen brought from Seymour Island pieces of fossil coniferous wood, and also fossil shells of Cucullea, Cytherea, Cyprina, Teredo, and Natica, having a close resemblance to species known to occur in Lower Tertiary beds in Britain and Patagonia. These fossil remains indicate in these areas a much warmer climate in past times. We are thus in possession of abundant indications that there is a wide extent of continental land within the ice-bound regions of the southern hemisphere. “Jt is not likely that any living land-fauna will be discovered on the Antarctic continent away from the penguin rookeries. Still, an Antarctic expedition will certainly throw much light on many Notices of Memoirs—Antarctic Exploration. avi geological problems. Fossil finds in high latitudes are always of special importance. The pieces of fossil wood from Seymour Island can hardly be the only relics of plant life that are likely to be met with in Tertiary and even older systems within the Antarctic. Tertiary, Mesozoic, and Paleozoic forms are tolerably well developed in the Arctic regions, and the occurrence of like forms in the Antarctic regions might be expected to suggest much as to former geographical changes, such as the extension of Antarctica towards the north, and its connection with, or isolation from, the northern continents, and also as to former climatic changes, such as the presence in Pre-Tertiary times of a uniform temperature in the waters of the ocean all over the surface of the globe.” After pointing out the importance of magnetic and pendulum observations, geodetic measurements, tides, and currents, the author referred to the depth of the Antarctic Ocean. “In regard to the depth of the ocean immediately surrounding the Antarctic continent we have at present very meagre information, and one of the objects of an Antarctic expedition would be to supplement our knowledge by an extensive series of soundings in all directions throughout the Antarctic and Southern Oceans. It would in this way be possible, after a careful consideration of the depths and marine deposits, to trace out approximately the outlines of the Antarctic continent. At the present time we know that Ross obtained depths of 100 to 500 fathoms all over the great bank extending to the east of Victoria Land, and somewhat similar depths have been obtained extending for some distance to the east of Joinville Island. Wilkes sounded in depths of 500 and 800 fathoms about 20 or 30 miles off Adélie Land. The depths found by the ‘Challenger’ in the neighbourhood of the Antarctic circle were from 1,300 to 1,800 fathoms, and further north the ‘Challenger’ soundings ranged froin 1,260 to 2,600 fathoms. To the south-west of South Georgia, Ross paid out 4,000 fathoms of line without reaching bottom. In the charts of depth which I have constructed I have always placed a deep sea in this position, for it appears to me that Ross, who knew very well how to take soundings, was not likely to have been mistaken in work of this kind. “The few indications which we thus possess of the depth of the ocean in this part of the world seem to show that there is a gradual shoaling of the ocean from very deep water towards the Antarctic continent, and, so far as we yet know, either from soundings or temperature observations, there are no basins cut off from general oceanic circulation by barriers or ridges, similar to those found towards the Arctic.” Dr. Murray next spoke of the deposits of the Antarctic Ocean. “The deposits which have been obtained close to the Antarctic continent consist of blue mud, containing glauconite, made up for the most part of detrital matters brought down from the land, but containing a considerable admixture of the remains of pelagic and other organisms. Further to the north there is a very pure diatom 00ze, containing a considerable quantity of detrital matter from 272. Notices of Memoirs—Antarctie Exploration. icebergs, and a few pelagic foraminifera. This deposit appears to form a zone right round the earth in these latitudes. Still further to the north the deposits pass in deep water, either into a Globigerina ooze, or into a red clay with manganese nodules, sharks’ teeth, ear-bones of whales, and the other materials characteristic of that deep-sea deposit. Since these views, however, as to the distribution of deep-sea deposits throughout these high southern latitudes, are founded upon relatively few samples, it cannot be doubted that further samples from different depths in the unexplored regions would yield most interesting information.” The subject of temperature of the Antarctic Ocean was then discussed. “The mean daily temperature of the surface waters of the Antarctic, as recorded by Ross, to the south of latitude 638° 8. in the summer months, varies from 27:3° to 33:6°, and the mean of all his observations is 29°85°. As already stated, his mean for the air during the same period is somewhat lower, being 28-74°. In fact, all observations seem to show that the surface water is warmer than the air during the summer months. ) “The ‘Challenger’ observations of temperature beneath the surface indicate the presence of a stratum of colder water wedged between warmer water at the surface and warm water at the bottom. This wedge-shaped stratum of cold water extends through about 12° of latitude, the thin end terminating about latitude 58° S., its temperature varying from 28° at the southern thick end to 32°5° at the northern thin end, while the temperature of the overlying water ranges from 29° in the south to 38° in the north, and that of the underlying water from 82° to 35°. This must be regarded as the distribution of temperature only during the summer, for it is improbable that during the winter months there is a warmer surface layer. “In the greater depths of the Antarctic, as far south as the Antarctic circle, the temperature of the water varies between 32° and 35° F., and is not, therefore, very different from the temperature of the deepest bottom water of the tropical regions of the ocean. The presence of this relatively warm water in the deeper parts of the Antarctic Ocean may be explained by a consideration of general oceanic circulation. The warm tropical waters which are driven southwards along the eastern coasts of South America, Africa, and Australia, into the great all-encircling Southern Ocean, there become cooled as they are driven to the east by the strong westerly winds. These waters, on account of their high salinity, can suffer much dilution with Antarctic water, and still be denser than water from these higher latitudes at the same temperature. Here the density observations and the sea-water gases indicate that the cold water found at the greater depths of the ocean probably leaves the surface and sinks towards the bottom in the | Southern Ocean, between the latitudes of 45° and 56°8. These deeper, but not necessarily bottom, layers are then drawn slowly northwards towards the tropics, to supply the deficiencies there Notices of Memoirs—Antarctic Exploration. 213 produced by evaporation and southward-flowing surface-currents, and these deeper layers of relatively warm water appear likewise to be slowly drawn southwards to the Antarctic area to supply the place of the ice-cold currents of surface water drifted to the north. This warm underlying water is evidently a potent factor in the melting and destruction of the huge table-topped icebergs of the southern hemisphere. While these views as to circulation appear to be well established, still a fuller examination of these waters is most desirable at different seasons of the year, with improved thermometers and sounding machines. Indeed, all deep-sea apparatus has been so much improved as a result of the ‘Challenger’ explorations, that the labour of taking specific gravity and all other oceanographical observations has been very much lessened.” In speaking of the pelagic life of the Antarctic Ocean, the author mentioned that ‘“‘In the surface waters of the Antarctic there is a great abundance of diatoms and other marine alga. These floating banks or meadows form primarily not only the food of pelagic animals, but also the food of the abundant deep-sea life which covers the floor of the ocean in these South Polar regions. Pelagic animals, such as copepods, amphipods, molluscs, and other marine organisms, are also very abundant, although species are fewer than in tropical waters. Some of these animals seem to be nearly, if not quite, identical with those found in high northern latitudes, and they have not been met with in the intervening tropical zones. The numerous species of shelled Pteropods, Fora- minifera, Coccoliths, and Rhabdoliths, which exist in the tropical surface waters, gradually disappear as we approach the Antarctic circle, where the shelled Pteropods are represented by a small Limacina, and the Foraminifera by only two species of Globigerina, which are apparently identical with those in the Arctic Ocean. A peculiarity of the tow-net gatherings made by the ‘Challenger’ Expedition in high southern latitudes, is the great rarity or absence of the pelagic larvee of benthonic organisms, and in this respect they agree with similar collections from the cold waters of the Arctic seas. The absence of these larve from polar waters may be accounted for by the mode of development of benthonic organisms to be referred to presently. It must be remembered that many of these pelagic organisms pass most of their lives in water of a temperature below 32° F., and it would be most interesting to learn more about their reproduction and general life-history.” As to the benthos life of the Antarctic Ocean, Dr. Murray said :— “ At present we have no information as to the shallow-water fauna of the Antarctic continent ; but, judging from what we do know of the off-lying Antarctic islands, there are relatively few species in the shallow waters in depths less than 25 fathoms. On the other hand, life in the deeper waters appears to be exceptionally abundant. The total number of species of Metazoa collected by the ‘Challenger’ at Kerguelen in depths less than 5V fathoms was about 150, and the number of additional species known from other sources from the shallow waters of the same island is 112, making altogether 242 DECADE IV.—YOL. Y.—NO. YI. 18 274 Notices of Memoirs—Antarctic Exploration. species, or thirty species less than the number obtained in eight deep hauls with the trawl and dredge in the Kerguelen region of the Southern Ocean, in depths exceeding 1,260 fathoms, in which eight hauls 272 species were obtained. Observations in other regions of the Great Southern Ocean, where there is a low mean annual temperature, also show that the marine fauna around the land in high southern latitudes appears to be very poor in species down to a depth of 25 fathoms, when compared with the number of species present at the mud-line about 100 fathoms, or even at depths of about two miles. “In 1841 Sir James Clark Ross dredged off the Antarctic continent species which he recognized as the same as he had been in the habit of taking in equally high Northern latitudes, and he suggested that they might have passed from one pole to the other by way of the cold water of the deep sea. Subsequent researches show that, as with pelagic organisms, many of the bottom-living species are identical with, or closely allied to, those of the Arctic regions, and are not represented in the inter- mediate tropical areas. For instance, the most striking character of the shore-fish fauna of the Southern Ocean is the reappearance of types inhabiting the corresponding latitudes of the northern hemisphere, and not found in the intervening tropical zone. This — interruption of continuity in the distribution of shore-fishes is exemplified by species as well as genera, and Dr. Gunther enumerates eleven species and twenty-nine genera as illustrating this method of distribution. The genus by which the family Berycide is repre- sented in the Southern Temperate Zone (Trachichthys) is much more nearly allied to the northern than to the tropical genera. ‘As in the Northern Temperate Zone, so in the Southern . . . . the variety of forms is much less than between the tropics. This is especially apparent on comparing the number of species constituting a genus. In this zone, genera composed of more than ten species are the exception, the majority having only from one to five.’ ‘ Polyprion is one of those extraordinary instances in which a very specialized form occurs at almost opposite points of the globe, without having left a trace of its previous existence in, or of its passage through, the intermediate space.’ “Speaking of the shore-fishes of the Antarctic Ocean, Giinther says: ‘The general character of the fauna of Magelhzen’s Straits and Kerguelen’s Land is extremely similar to that of Iceland and Greenland. As in the Arctic fauna, Chondropterygians are scarce, and represented by Acanthias vulgaris and species of Raya As to Acanthopterygians, Cataphracti and Scorpzenide are repre- sented as in the Arctic fauna, two of the genera (Sebastes and Agonus) being identical. The Cottide are replaced by six oe of Trachinide, remarkably similar in form to Arctic types . Gadoid fishes reappear, but are less developed; as usual, they are. accompanied by Myaxine. The reappearance of so specialized a genus as Lycodes is most remarkable.’ ! * Gunther, ‘‘ Study of Fishes,”’ pp. 282-290; Edinburgh, 1880. Notices of Memoirs—Antarctic Exploration. 275 ‘These statements with reference to shore-fishes might, with some modifications, be repeated concerning the distribution and character of all classes of marine invertebrates in high northern and high southern latitudes. The ‘Challenger’ researches show that nearly 250 species taken in high southern latitudes occur also in the northern hemisphere, but are not recorded from the tropical zone. Fifty-four species of seaweeds have also been recorded as showing a similar distribution.! Bipolarity in the distribution of marine organisms is a fact, however much naturalists may differ as to its extent and the way in which it has originated. “‘ All those animals which secrete large quantities of carbonate of lime greatly predominate in the tropics, such as Corals, Decapod Crustacea, Lamellibranchs, and Gasteropods. On the other hand, those animals in which there is a feeble development of carbonate of lime structures predominate in cold polar waters, such as Hydroida, Holothurioidea, Annelida, Amphipoda, Isopoda, and Tunicata. This difference is in direct relation with the temperature of the water in which these organisms live, a much more rapid and abundant precipitate of carbonate of lime being thrown down in warm than in cold water by ammonium carbonate, one of the waste products of organic activity. “In the Southern and Sub-Antarctic Ocean a large proportion of the Hchinoderms develop their young after a fashion which precludes the possibility of a pelagic larval stage. The young are reared within or upon the body of the parent, and have a kind of commensal connection with her till they are large enough to take care of themselves. A similar method of direct development has been observed in eight or nine species of Echinoderms from the cold waters of the northern hemisphere. On the other hand, in temperate and tropical regions the development of a free-swimming larva is so entirely the rule that it is usually described as the normal habit of the Echinodermata. This similarity in the mode of development between Arctic and Antarctic Echinoderms (and the contrast to what takes place in the tropics) holds good also in other classes of Invertebrates, and probably accounts for the absence of free- swimming larve of benthonic animals in the surface gatherings in Arctic and Antarctic waters. “What is urgently required with reference to the biological problems here indicated is a fuller knowledge of the facts, and it cannot be doubted that an Antarctic expedition would bring back collections and observations of the greatest interest to all naturalists and physiologists, and without such information it is impossible to discuss with success the present distribution of organisms over the surface of the globe, or to form a true conception of the antecedent conditions by which that distribution has been brought about.” Dr. Murray concluded his paper as follows :— “There are many directions in which an Antarctic Expedition would carry out important observations besides those already touched * Murray and Barton, ‘‘ Phycological Memoirs of the British Museum,”’ part iii ; London, 1895. 276 Reviews— Wachsmuth & Springer’s Monograph on Crinoids. on in the foregoing statement. From the purely exploratory point of view much might be urged in favour of an Antarctic Expedition at an early date; for the further progress of scientific geography it is essential to have a more exact knowledge of the topography of the Antarctic regions. This would enable a more just conception of the volume relations of land and sea to be formed, and in connection with pendulum observations some hints as to the density of the sub-oceanic crust and the depth of ice and snow on the Antarctic continent might be obtained. In case the above sketch may possibly have created the impression that we really know a great deal about the Antarctic regions, it is necessary to restate that all the general, conclusions that have been indicated are largely hypothetical, and to again urge the necessity for a wider and more solid base for generalizations. The results of a successful Antarctic Expedition would mark a great advance in the philosophy—apart from the mere facts—of terrestrial science. ‘No thinking person doubts that the Antarctic will be explored. The only questions are: when? and by whom? I should like to see the work undertaken at once, and by the British Navy. I should like to see a sum of £150,000 inserted in the estimates for the purpose. The Government may have sufficient grounds for declining to send forth such an expedition at the present time, but that is no reason why the scientific men of the country should not urge that the exploration of the Antarctic would lead to important additions to knowledge, and that, in the interests of science among Hnglish- speaking peoples, the United Kingdom should take not only a large but a leading part in any such exploration.” The Duke of Argyll, Sir J. D. Hooker, Dr. Nansen, Dr. G. Neumayer, Sir Clements Markham, Dr. Alexander Buchan, Sir A. Geikie, Dr. Sclater, Professor D’Arcy Thompson, Admiral Sir W. J. L. Wharton, and others, took part in the discussion which followed. a5% Jah Wh dE dah WY Se WacHsMUTH AND SpPRINGER’s MonoGRaPH oN ORINOIDS. Toe Norte American CrinoipgpA Camerata. By CHARLES WacusmutTH and FRANK Sprincer. Mem. Mus. Comp. Zool. Harvard, vols. xx and xxi, containing 888 pp. and 88 plates. (Cambridge, U.8.A., May, 1897). First Notice. N the last letter that he wrote me, Charles Wachsmuth repeated a wish already expressed by word of mouth, namely, that in | some English publication I should review this grand monograph, then in active preparation. Although, through the kindness of Mr. Alexander Agassiz and Mr. Frank Springer, a copy has been in my hands for a twelvemonth, yet the wish of my departed friend is still unfulfilled. The reasons for delay have been two. The first is the size and importance of the work, coupled with my desire to do if justice. What has taken twenty years to write cannot be digested Reviews—Wachsmuth &§ Springer’s Monograph on Crinoids, 277 and criticized at a week’s notice. The second reason is the large amount of personal controversy and criticism of my own writings. Of this so much was made in certain premature reviews published in America, that I could not, at an earlier date, have avoided some remarks in self-defence; and I was unwilling to attack one whose mouth had so recently been sealed by death. The time has at last arrived when I can venture on a satisfactory appreciation of this work, and when argument may meet argument without suspicion of personal bitterness. Therefore, with the kind permission of the Editor of the Grotocican Magazine, I propose to deal, in a series of notices, with the several sections of the book, directing special attention to facts or opinions first published therein. The perusal and reperusal of this work has brought to light a few errors. The correction of these, as the pages are passed in review, will, I trust, be ascribed less to a love of censoriousness than to a desire to increase the usefulness of a book that must be the standard of reference for many years to come. Several of these errors are by no means peculiar to Messrs. Wachsmuth and Springer, and it was hardly in their power to discover them. ' This memoir consists of three parts :—Introductory, dealing with the history of our knowledge and with terminology ; Morphological, dealing with the elements of the crinoid skeleton, and with such internal organs as leave traces in the fossils; Systematic, first dealing with the classification of the Crinoidea, and then describing the North American genera and species referred by the authors to their Order Camerata. Hight plates and a few text-figures elucidate the morphological questions discussed, while seventy-five illustrate the descriptions. The drawings have been made in pencil by C. R. Keyes, J. L. Ridgway, and A. M. Westergren, and have been reproduced by the Heliotype Printing Co., Boston. There are also a few drawings by G. Liljevall. This mode of illustration is the most satisfactory for paleontological work when fine detail is to be shown. Its peculiar difficulties have been overcome, so far as possible, by the attention of Mr. Westergren. Many of the figures are admirable examples of draughtsmanship; whether they are correct cannot be decided (except in a case to which I shall recur) without comparison with the specimens figured. A thoughtless habit of praising scientific illustrations because they look pretty has made the reputation of many a careless draughtsman. The magnification of the figures should have been stated in all cases where they are not of natural size, not merely in some cases. Information is given as to the collections in which the figured specimens are, but the original locality of each specimen is not indicated. The type-specimens are distinguished, but nothing tells us that several other specimens have been already figured elsewhere. In a few instances it is hard to see how the information that is given can be correct. It is, for example, impossible that figs. 2a and 26 on pl. xv should represent, as they are said to do, the ventral and dorsal aspects of “the same specimen” of Gilbertsocrinus dispansus ; even more does this apply 278 Reviews—Wachsmuth & Springer’s Monograph on Crinovds. to figs. 2c and 2d. I would also suggest that figs. 5 and 7 of pl. v are incorrectly described; if they really are in the position stated, then they show a variation of fundamental structure, remarkable not merely in itself but also from the fact that it is not alluded to in the text. While grateful for the numerous figures, so admirably illustrative of specific form, one could have wished to see more drawings of detail on an enlarged scale. The pores of Batocrinus, to instance a structure much discussed by our authors, are nowhere adequately figured. Similarly, the representations of the assumed slits or pores in the anal sac of the Fistulate Inadunata are not enough magnified to form evidence worth opposing to the numerous enlarged and detailed figures already published by me as proof that these supposed slits are nothing but deep folds. It is a great boon to have gathered in one volume such charming and, no doubt, trustworthy figures of nearly all the species of North American Camerata; but it may be suggested to future workers that the time has gone by for nothing but pictures of specimens, however exquisite. We want accurate drawings of structure and variations of structure, represented in the most intelligible manner possible. Apparently it is thought undignified or inartistic to put reference letters on the plates illustrating a book of this importance. Such, at any rate, is the custom, with the result that it is often hard to follow descriptions of structure. When an exact drawing of an obscure specimen is given, and in many cases most rightly given, let us at least have an explanatory diagram. Too many of our scientific ‘‘ships”’ are spoiled for want of this “‘ha’porth of tar”; though this is not always the author’s fault. One feature of Messrs. Wachsmuth and Springer’s plates is the consistency of orientation : “in illustrating the plates of the calyx, the dorsal view is figured with the anal interradius wp, and the ventral view with the anal side down. Right and left remain the same in both cases.” This example should always be followed; and when a specimen is drawn from the side its orientation should invariably be stated. Let us turn now to the text. The Historical Introduction is of value chiefly for its account of discovery and work in North America. Fourteen bundred crinoid species from that country are now described, but in 1858 only seventy had been defined. In that year remarkable finds were made, and the now famous localities of Burlington, Crawfordsville, Keokuk, and Louisville yielded hundreds of perfect specimens. Troost had already reported, though not published, 86 new species and 16 new genera from Tennessee, but Burlington furnished over 300 species, a greater number than those hitherto known from the whole world. Crinoid-collecting became _ the rage, while “men of science, anxious to publish the new forms, — and fearing they might be preceded by competitors, brought out preliminary descriptions to secure priority for their species. These descriptions, in many cases, were so indefinite that the identification — of the species was almost impossible, and this created considerable annoyance and labour to later writers.” It is to be feared that the creation of annoyance in this manner has not yet ceased, and that it Reviews—Wachsmuth & Springer’s Monograph on Crinoids. 279 is by no means the prerogative of writers on crinoids. Many descriptions issued forty years ago as “ preliminary ” remain uncom- pleted to this day. It is pleasant to find that the earlier English authors are not accused of similar bad faith; at the same time, “their descriptions in many cases are so primitive that neither genera nor species can be identified.” The account of the American localities for fossil crinoids, given in this part of the work, is interesting and useful enough to indicate the value there would be in a complete list of such localities with the geological horizon as now ascertained. If the names of the chief collectors could be added, as here, and also a list of the chief species from each locality, so much the better. There arein the Old World, and doubtless in the New, numerous ancient collections of North American crinoids, with somewhat imperfect labels bearing names, both of locality and horizon, which it is hard to identify with names on modern maps or in modern manuals of geology. Nor would it be only on such obscurities that the table we desire would throw light. If drawn up by a competent authority, such as Mr. Springer, it would advance the study of distribution in space and time, an accurate knowledge of which is so necessary to the zoological evolutionist. In this research no help is to be despised. As our authors say in a passage that comes with great weight from practical collectors and paleontologists : “The trouble is that all our generalizations are necessarily based upon the Crinoids as they are represented in our museums, and not upon the Crinoids as they actually existed in geological time, which is a very different thing. It is like trying to reconstruct a book from detached fragments of the chapters, some of them written in hieroglyphics for whose decipherment the key has not yet been found. We are accustomed to speak of the imperfection of the geological record, but it is doubtful if in our practical studies we always bear in mind what this really means. . . . How much do we actually know of the life represented in the rocks accessible to us? Nearly all the known Silurian Crinoids come from the out- croppings of the strata at two localities in Hurope, and three or four in America. The Devonian exposures producing well preserved Specimens are even more limited. The Lower Carboniferous collections are better and more widely distributed, but are in- significant atter all. Take the Burlington and Keokuk limestones, which in a few localities have produced more Crinoids in number and species than any other formation. ‘They consist of several hundred feet of strata almost entirely composed of the comminuted remains of countless myriads of Crinoids—fragments which are worthless to the Paleontologist. It is only rarely that a thin layer is found in which the calcareous skeletons are preserved well enough for study ;—little basins of limited extent, in which, during a period of temporarily quiet waters, the Crinoids lived, died, and were imbedded at sufficient depths to escape the destructive effects of shore action. If the collector happens to be present when one of these colonies is un- covered by the quarrymen, the specimens may be rescued for the 280 Reviews—Wachsmuth & Springer’s Monograph on Crinoids. benefit of Science. But it is an even chance that they will be buried in the debris of the quarry, broken up for ballast, or walled up in the foundation of a building, and thus be lost again. Out of the thousands of square miles in which these rocks lie nearest the surface, all the collections that have ever been made represent only the imperfect gleanings of not more than a few acres. If it be supposed that we get, even in this way, a fair representation of the crinoidal life of that period, the answer is that almost every new discovery of ‘nests’ or ‘colonies’ of good specimens brings to light new forms, and that species or genera hitherto very rare are often suddenly found within a limited space quite abundantly. In the Upper Coal Measures, to judge from our books and museums, one would suppose that Crinoids were well-nigh extinct. Scarcely a dozen species are known, and most of them only by their lower calyx plates. Yet there are many beds in this formation which extend over hundreds of thousands of square miles from the Missouri Valley far into the Rocky Mountains and tilted up along their flanks, which are completely filled with fragments of Crinoids. Suddenly the collectors at Kansas City, who have studied these rocks for years, discover an abundant deposit of well preserved specimens in a shale so soft that a few minutes’ rain dissolves them into unrecognizable fragments.” (pp. 167-8.) The historical account of the European literature will no doubt be of use to American workers, but it would have been of more value to them, and to all of us, had Messrs. Wachsmuth and Springer been in a position to verify their references and quotations instead of copying from De Koninck and W. B. Carpenter. The writings of Agricola and Rosinus may not be accessible to workers in Iowa or New Mexico, but no specialist on Crinoidea can be forgiven for misrepresenting J.S. Miller and Johannes Miller, as do our authors. Let me substantiate this criticism in detail. Agricola, we are told (p. 11), applied the name “ Hnerinus to the calyx of Enerinus liliiformis, at that time the only Crinoid in which a crown had been found in connection with the stem.” This is the intensification of an error already bad enough. It was Harenberg who, in 1729, thus misapplied Agricola’s term ncrinus, which originally bore the same relation to Pentacrinus asfntrochus bore to Trochites, i.e. Encrinus meant a series of star-shaped columnals. What Agricola and the rest really did say is set forth in my recent paper, ‘‘ Pentacrinus: a name and its history” (Natural Science, vol. xii, pp. 245-256). The next paragraph says that “Rosinus . . . . was the first writer to show that the Crinoids were not plants, as before then generally supposed, but were closely related to the Asterids.” Rosinus was a writer of much merit, but the date of his “ De Stellis Marinis quondam nunc Fossilibus Disquisitio” was 1719, whereas Lihuyd had published even more correct views in his “ Lithophylacti Britannici Ichnographia,” issued at London and Leipzig in 1699 (see Natural Science, loc. cit., also vol. xii, pp. 292 and 431). Wachsmuth and Springer’s error, copied from De Koninck, was long ago corrected by W. B. Carpenter. Reviews— Wachsmuth & Springer’s Monograph on Crinords. 281 Guettard next receives some praise that is far too faint. The name “ Palmier marin” was not his invention; the animal to which it was applied has been more correctly known as Pentacrinus asteria than as P. caput-meduse; there are three misprints in the reference to his paper. Blumenbach (the date of whose “‘ Handbuch der Naturgeschichte,” Ed. 1, is 1779, not 1780) obtains “the credit of having been the first writer who ranked them [erinoids] with the Asteroids and Ophiurids among the order ‘ Vermes crustacei,’ which corresponds approximately to our present Echinoderms.” He may have been the first post-Linnean writer to do this; but he was only following Llhuyd in both arrangement and terminology. Moreover, in the edition of the “Handbuch” cited by our authors, Blumenbach referred the Echinoderms to ‘Cartilaginea,’ associating the crinoids with various Hydrozoa. It was not until 1788 that he placed them under ‘ Crustacea.’ J. §. Miller’s definition of a crinoid is turned into nonsense on p. 12. Miller wrote as follows, but Wachsmuth and Springer have quoted only the italicized words: “ An animal with a round, oval, or angular column, composed of numerous articulating joints, supporting at its summit a series of plates or joints forming a cup-like body containing the viscera, from whose upper rim proceed five articulated arms, dividing into tentaculated fingers, more or less numerous, surrounding the aperture of the mouth, situated in the centre of a plated integument, which extends over the abdominal cavity, and is capable of being contracted into a conic or proboscal shape.” The omissions can scarcely be intentional. On p. 14 “Heisinger (1837)” no doubt refers to Hisinger’s “‘Tetheea suecica,” which was published in that year, and not to Heusinger, who also was an early writer on crinoids. On the same page it is said that Joh. Miiller’s paper “ Ueber den Bau des Pentacrinus caput-meduse” appeared in 1840. The first part of it was read in that year, but none was published till 1848. In this paper Miiller wrote as an anatomist rather than as a systematist, and it is not easy to understand what his precise views as to the classification may have been. Probably he wrote thus of set purpose, recognizing that the time for a formal classification of crinoids had not arrived, and intending only to give names to certain plans of structure. Nevertheless, my interpretation of Miiller is so different from that of Messrs. Wachsmuth and Springer that I can only suppose they have not referred to the original paper, incredible though such an inference may seem. “ Miiller,” they write, “divided the Orinoids into three great groups: the ‘ Crinoidea Articulata,’ the ‘ Crinoidea Tessellata,’ and the ‘ Crinoidea Costata.’” And again: “The Tessellata were subdivided by Miller into two groups: Orinoidea with arms, and Crinoidea without arms. ‘To the former he referred all true Crinoids and the Cystid genus Caryo- crinus. . . . . The armless Crinoids comprise the ‘ Pentremites’ (Blastoidea) and ‘Spheronites’ (Cystidea).” Instead of criticizing these statements in detail I will contrast 282 Reviews—Wachsmuth & Springer’s Monograph on Crinotds. with them my interpretation of Miiller’s intentions. Miiller’s ‘Crinoidea’ included all Pelmatozoa then known. His first division was into those with arms and those without, the former group being the ‘Crinoidea brachiata’ of writers who preferred a Latin terminology, and the latter including ‘ Pentremites’ and ‘Spheeronites.’ Among crinoids with arms, the stalked forms were always distinguished from the unstalked; but it is not clear that Miller intended this as a prime classificatory division, although the point should not be omitted from any account of his views. Apart from this he noted, not three, but five divisions in the Crinoidea brachiata, viz.: (1) the Articulata, both stalked, as Pentacrinide, and unstalked, as Antedonide ; (2) the Tessellata, both stalked, as most Paleozoic crinoids, and unstalked, as Marsupites; (8) the Costata, unstalked only, and not to be described as a “ great group,” since it included only the small genus Saccocoma ; (4) the Testacea, erected for the reception of Haplocrinus mespiliformis, and defined thus: cup and tegmen form a firm, connected test, with five ambulacra running up to the mouth; (5) Holopus, “eine ganz eigenthtimliche Abthei- lung der festsitzenden Crinoiden” (p. 210), with sessile cup and, apparently, no anus (p. 229). ‘The stalked crinoids without arms,” writes Miller (p. 229), “form two Families. Both are most probably [unlike the Tessellata] provided with distinct mouth and anus.” The first Family is further distinguished from Tessellata by having a star-shaped arrangement of ambulacra on the ventral surface of the calyx: ‘‘these are the Pentremites.” The second Family, which may be described in Miiller’s words as ‘“ Die Tessellata dieser Abtheilung, ohne Stern von Tentakelfelder,” are the Spheeronites “with their genera as established by Mr. von Buch (1840).” It was probably this phrase “Die Tessellata dieser Abtheilung” that led Messrs. Wachsmuth and Springer to suppose that Muller really meant to class the Cystidea in the Tessellata; surely he merely meant to imply that they followed in this one respect the ‘tessellate’ type of structure. In any case the phrase shows that he did not place the Blastoidea with the Tessellata; in fact, on the previous page he compares them, much in the same way, with the Testacea. It results from the above that the statement on p. 23, that Zittel in 1879 followed Miiller in his classification, is also incorrect. For Zittel really did divide the Crinoidea brachiata, or Kucrinoidea as he called them, into three suborders, merging Holopus and the Testacea in the Articulata. I do not know what is meant by “ Roemer’s classical memoir on the Cystidea,” but everybody knows his memoir on the Blastoidea, and knows that it was published in 1851, not in 1855 as would follow from the remarks on p. 17 of the present monograph. The reference to Pictet’s Paléontologie on the same page should not be “Tom. v” but ‘‘ 2¢ edition, tom. iv.” The account of the successive classifications proposed by Wachsmuth and Springer themselves is clear, and will be welcomed by many who have not mastered all the previous Reports and Proceedings—Geological Society of London. 283 writings of these authors. But in the account of P. H. Carpenter’s views is a curious omission. The division of the Crinoidea by Wachsmuth and Springer into Paleocrinoidea and Stomatocrinoidea was accepted by Carpenter and Etheridge, jun., in 1881 (Ann. Mag. Nat. Hist., [5,] vii, 281-298) ; the latter authors, however, laid more stress on the asymmetry of the posterior interradius in Palzeocrinoidea than on the condition of the tegmen, and therefore suggested the names Irregularia and Regularia. It is personally gratifying to gather from this history that the first rejection of the division into Paleocrinoidea and Neocrinoidea must have been independently and synchronqusly published by these eminent American authorities and by myself (February, 1889) ; further, that in applying the logical consequences of the tegminal structure of Zaxocrinus to all Crinoidea, I actually preceded them by half a year (April, 1890). No one will suffer from the absence of all allusion to this in the present monograph, which certainly does not err in the direction of underestimating any contributions that I have so far been able to make to our knowledge of the Crinoidea. Such errors as have been pointed out do not materially detract from the value of the monograph, and we can readily forgive a few such slips when we remember the age and ill-health with which the senior author had to struggle, and the constant pressure of other occupation that must have made his colleague’s revision of the proofs a task of no ordinary difficulty. These circumstances will, I hope, always be borne in mind by any who read the present or future chapters of this review. F. A. Batuer. (Lo be continued.) REPORTS AND PROCHEDINGS. nt GeotogicaL Soctery oF Lonpon. I.—April 20, 1898.—W. Whitaker, B.A., F.R.S., President, in the Chair. The following communications were read :— 1. “Note on an Ebbing and Flowing Well, at Newton Nottage (Glamorganshire).” By H. G. Madan, Esq., M.A., F.C.S. (Com- municated by A. Strahan, Esq., M.A., F.G.8.) This well lies in a direct line drawn north and south from the church of Newton Nottage to the sea, about 80 yards south of the church and 500 yards from the sea. Sand-hills about 20 or 30 feet high lie between it and the sea. A range of Carboniferous Lime- stone cliffs runs east and west to the north of the church, while the same formation crops out in the sea at half-tide level. Between the two there is a band of Keuper conglomerate covered in one place at least by 7 feet of brown loamy clay with pebbles. At the shore- junction of conglomerate and limestone numerous springs occur, and it is in the conglomerate that the well is sunk, its bottom being 8 feet above ordnance datum. A series of about forty observations made at intervals of an hour (and in many cases at the intermediate half-hours) during three 284 Reports and Proceedings—Geological Society of London. consecutive days, enables the author to construct a curve showing the relationship existing between the rise and fall of the tide on the coast and that of the water in the well. The result is to establish the existence of a wave in the well of the same frequency as the tidal wave, but delayed, or with an establishment of, three hours (plus or minus a few minutes). The analyses of water taken from the well at its highest and lowest show no difference, so that no sea-water enters the well directly. On the other hand, the slight brackishness of the water appears to prove the diffusion of a small amount of salt water into the well. 2. “ Petalocrinus.” By F. A. Bather, Esq., M.A., F.G.S. Certain curious fan-like objects, obviously echinodermal, have for a long time been preserved in the Riks-Museum at Stockholm, but their significance was first definitely ascertained when similar fossils were found in Jowa, and brought to England by Mrs. Davidson. The latter were described by Mr. Stuart Weller in a paper entitled “ Petalocrinus mirabilis (n.sp.), and a New American Fauna”; and the former, with fresh material obtained by Mr. Weller from various American localities, are the subject of the present communication. The Silurian crinoid genus Petalocrinus, Weller, is discussed, on the evidence of all the original material from Jowa and of the further material above mentioned. The replacement of the original material of the Iowan fossils by silica has taken place only in certain parts, forming a number of siliceous boxes, as it were, which are either hollow or more or less filled with chalcedony or crypto- crystalline silica. They are therefore neither casts nor impressions, and details of structure are frequently destroyed. Petalocrinus is shown to have a dicyclic base—not monocyclic, as originally described. The structure of the tegmen is shown to be that of the Cyathocrinoidea. The arm-fans characteristic of the genus are proved to have been formed by fusion of the branches of an arm of Cyathocrinid type. In them, description is given for the first time of axial canals, covering-plates, the articular facet, and various minor structures. The species P. major, Weller, is shown to be an Omphyma; but P. mirabilis, Weller, the genotype, is re- described, and with it five new species—two from Iowa; three, as well as a possible mutation of one of them, from Gotland. A family Petalocrinide, descended from the Cyathocrinide, probably by way of Arachnocrinus, is founded for the reception of this genus. 3. “On the Origin of the Auriferous Conglomerates of the Gold Coast Colony (West Africa).”” By Thomas B. F. Sam, Esq., C.H. (Communicated by J. Logan Lobley, Esq., F.G.S.) This paper gives an account of a recent journey from Adjah Bippo to the Ankobra Junction in the Gold Coast Colony. A range of clay-slate hills is succeeded for six miles by flat ground in which diorite was found, and that by a lofty hill in whieh clay-slate dipping east occurs. ‘The Teberibie range with reefs of conglomerate, and a second range with similar reefs, were crossed. Reports and Proceedings— Geological Society of London. 285 Gold-bearing alluvia are briefly described, and the gold is sup- posed to have come from the hills. The Adjah Bippo, Takwa, and Teberibie formations are considered to be part of a syncline. Some conclusions are drawn as to the method of formation and probable auriferous character of the rocks. II.—May 4, 1898.—W. Whitaker, B.A., F.R.S., President, in the Chair. The following communications were read :— 1. “The Carboniferous Limestone of the Country around Llan- dudno.” By G. H. Morton, Hsq., F.G.S. Llandudno is so well known and fréquently visited, that the Carboniferous Limestone and. the subdivisions into which it is divided by clear lithological characters may be more easily examined there than at any other similar locality. The subdivisions of ‘‘ Lower Brown,” ‘‘ Middle White,” and ‘“‘ Upper Grey,” along the broad belt of limestone from Llanymynech to Prestatyn, and around the Vale of Clwyd, Abergele, and Llandulas, have been so frequently described in the Proceedings of the Liverpool Geological Society that it is unnecessary to give any general description of them. At Llandudno the precipitous Great Orme’s Head presents fine sections of the Carboniferous Limestone and the subdivisions referred to, and may be easily examined (with the aid of the appended geological map), in a continuous series of cliffs, ridges, and quarries. The entire succession is, however, not perfect, for the highest beds of the “Upper Grey Limestone” have been denuded, and at the Little - Orme’s Head .the subdivision is altogether absent. Copper-lodes on the Great Orme’s Head appear to have been worked by the Romans, and again in recent years until abandoned fully thirty years ago. Some of the lodes are faults, but little can be ascertained about them now, and only two or three are faults with any appreciable amount of dislocation. It is to the undulation of the limestone that the ever-varying dip of the beds is attributed. Numerous fossils occur in the ‘‘ Upper Grey Limestone,” and a few are peculiar to the subdivision and the locality, but of these only a single specimen of each has been found. Productus margaritaceus is abundant, though only an occasional species in other localities, and not found at a lower horizon anywhere else in North Wales. Other species, such as Orthis Michelini, formerly supposed to be peculiar to the “‘Upper Grey Limestone,” have been found at the base of the “‘ Middle White Limestone,” at the Flagstaff Quarry on the Marine Drive, near the Happy Valley. The dolomitization of the Carboniferous Limestone is remarkable, and almost peculiar to that around Llandudno, though it also occurs at Penmon in Anglesey. The ‘ Lower Brown Limestone ” has been almost entirely converted into dojomite, and portions of the over- lying subdivisions. The filling of the faults has often been changed into dolomite, and the alteration of the Limestone has generally been very capricious: the author’s opinion being that the change took place after the dislocation of the strata in post-Triassic times. *spoq-abhdojn.1ap “spoq-snpdv.ihnugay, ” “svore asouy jo soon TOYO OY} TFTA soy Meppryg oT yo SmoTstATp ony yo sdrystorepar ory Surmoys orqey, ‘sovy-yjnbuT ¢ “OOPVULOL, d (9) “spaq-snpdnuhohug (wv) “‘SOPLTS ALPPHIG ToA0'T “SIUALY IOMOT “StueLY [PPTL ‘Story teddy “UALAULY'T “OI OMAL “spoq-snpdpshv.ayT, IOMoT (a) ‘spoq-supdpihoyng (9) ‘spoq-smdnihv.uay roddg (v) “So}2[S AVPPPIG TPP ‘snadnibopdig Yyta ‘spog TILs10q[H (2) “speg umqr[t (”) ‘soqeyg Aeppryg edd g (‘SOLIOG OIUBOTO A oTepMOTIOG) s S Ss =~ Ss WN > 'S = ‘dnory “sorvyg S “OUO4SOUUT] - 977.1000 ).40) BS ee ES daqont) ouvuueg = aS aS ‘ Oni aSe = (l’H) S RS) sndhy “yo snjydvuhoyhygq Jo wuo7 ' S S | ‘SoTlog Leg 2. ‘snunuab “(7 (0) euo7 S yo sjavd aaaory ¢ Ss ‘sngdn.sbossoj 9 (a) ou07 SH 8 Se S g 0 © Ss = : 3-snpdnwhopjao ag sopeys-sgdn.hopjao1y : E = jo Fr eb S Ee @O ae SouoZ IOSITT = S S RS ‘OUTUTIAT, UWLIV ‘(VINVOS) Naaamg "VaVNVQ, ‘GNVILOOY “Gg €© @ N ‘SHIVA “9 “LOIMLSIGG AUWT (‘184 “do0g) ‘soqvlg Meppryg oy fo vuneg-oytpoydvry ory uo zoded s,sorpy “TT +O SSTPL OVAYSNITE OF, Correspondence—Professor T. G. Bonney. 287 2. “The Graptolite-Fauna of the Skiddaw Slates.” By Miss G. L. Elles. (Communicated by J. E. Marr, Hsq., M.A., F.R.S., F.G.S.) This paper deals not only with the collections of the author, but with the Dover Collection and others preserved in the Woodwardian Museum, with the collections of Professor H. A. Nicholson, Mr. Postlethwaite, and that of the Keswick Museum of Natural History. An account of the literature, both stratigraphical and paleontological, of the Skiddaw Slates is given, followed by a list of all the graptolites known from the beds. This list comprises 22 genera and 59 species. In the ensuing description all the known genera and species are noted, and corrections and additions made to existing knowledge con- cerning the diagnosis, structure, and development of many of them. The following seven species, new to this country—Sryograptus ramosus (Brog.), Clonograptus tenellus (Linn.), Trochograptus diffusus (Holm), Pterograptus (Holm) sp., Didymograptus gracilis (Térnq.), Azygograptus suecicus (Mbg.), Diplograptus appendiculatus (‘Tornq. MS.)—and ten new species and varieties are described. A table showing the distribution of the Skiddaw graptolites in the Arenig rocks of Great Britain, in the Phyllograptus-Skiffer, etc., of Sweden, and the Quebec Group of Canada is given, and the accompanying (contracted) table (p. 286) expresses the relationships of the divisions of the Skiddaw Slates with the rocks of these areas. In conclusion, the author is struck with the remarkable resem- blances existing between the species of various genera; these can be so easily explained by supposing that the forms in question are the results of development along certain lines, that she offers the suggestion that this is their real origin. In dealing with the phylogeny, she divides these graptolites into two groups— (1) Those derived from a Bryograptus-form. (2) Those derived from a Clonograptus-form. To the first group belong 15 named graptolites from the Skiddaw Slates and 4 species from other localities; and to the second 12 Skiddaw species and 2 others. CORRESPONDENCE. THE LLANBERIS UNCONFORMITY. Srr,—As my name has figured much in your pages for the last two months permit me to say that I have no intention of replying to Mr. Blake’s ‘‘ Revindication of the Llanberis Unconformity.” My chief reasons for adopting this course are: (1) It would be necessary for me to investigate on the ground all statements which rest only on his authority, because hitherto I have so often found that what he deems facts appear to me to be fancies. For this task I have now no time, being tied much more closely to London than was formerly the case, so that my short vacations are devoted to work which offers greater attractions. (2) Controversy with 288 Obituary—Edward Wilson, F.G.S. Mr. Blake is endless. What is one year “a crucial test” and ‘a decisive proof” is thrown overboard in another as absolutely unimportant, nay, as a good riddance (compare Q.J.G.S., 1888, p. 284, with id., 1892, p. 244, and this Magazine, 1891, p. 487). It is like seeking to tie down Proteus. Prove him wrong, that point is dropped and another is started: “ Primo avulso non deficit alter Plumbeus.” I will therefore merely say that some of the slips or changes of opinion, which he attributes to me, exist only in his own imagination, and that in regard to one or two points where I have altered my mind (and have never made any secret of it as he seems to insinuate) I am not ashamed to draw fresh inferences when new facts have been discovered. Thus I have had to unlearn much that I was taught in my younger days about crystalline and metamorphic rocks by those to whom I looked up. So I am content (as I believe Miss Raisin is) to leave Mr. Blake apparently in possession of the field, unless it should happen that some former pupil, anxious to flesh a maiden sword, should crave for a subject, in which case I promise to recommend to him the “ Revindication of the Llanberis Unconformity.” T. G. Bonney. University Cotiecr, Lonpon. May, 1898. @aS sete Acie pra Epwarp Witson, F.G.S.—We have just received (May 23rd) the sad intelligence of the loss of our highly esteemed fellow-worker in Geology, Edward Wilson, F.G.8., for fourteen years the untiring Curator of the Bristol Museum, whose published papers have appeared in the Quarterly Journal of the Geological Society, the GrotogicaL Magazine, and other periodicals. In 1888 he received the award of the Murchison Fund from the Council of the Geological Society (of which Society he had been elected a Fellow in 1872). Mr. Wilson’s published papers date back for thirty years, and deal with the Red Marls, the Keuper and Bunter Beds, the Rheetic, and Lias. He has also published papers upon the Liassic Gasteropoda, etc. At the time of his death he was investigating the Uphill Cave Deposits, near Weston-super-Mare. He passed away, after three weeks illness, on May 21st, 1898, in his 49th year. MES CHET, AINO US- eS ee GerorocicaL Survey ApporintmMents.—The vacancy caused by the resignation of Mr. W. W. Watts has been filled by the appoint- ment of Mr. W. Pollard, M.A., D.Sc., who joins as an Assistant Geologist in the Petrographical Department; and that caused by the retirement of Mr. De Rance has been filled by Mr. C. B. Wedd, B.A., as Assistant Geologist. In Ireland, the petrographical work will be carried on by Mr. H. J. Seymour, B.A., who succeeds as Assistant Geologist to the post left vacant by the resignation of Professor Sollas. ee ala Sere eee tee a GEOL. MAG. 18908. Dec. IV, Vol. V, Pl. Sguatina acanthoderma, O. Fraas, 1854. Lithographic Stone: Nusplingen, Wiirtemberg. THE GHOLOGICAL MAGAZINE. NEWESERIES! “DECADE (Vin Vol W. No. VII.—JULY, 1898. @rew sears Are) Asses sea @ ieee I.—Preniuinary Nott on a New Specimen or SquaTina FROM THE LirHoGRAPHIC STonE oF NUSPLINGEN, WURTEMBERG. By Artuur SmitrH Woopwarp, F.L.S., F.G.S. PLATE X. EVERAL specimens of extinct species of the angel-fish or monk- fish (Squatina) are already known from the Lithographic Stone (Lower Kimmeridgian) of Bavaria, Wiirtemberg, and France; and some of these are in an admirable state of preservation. ‘Two forms are clearly distinguishable—the one a small fish not more than 0-15 m. in length, with a dense armour of rounded dermal tubercles on the anterior border of the head and each of the paired fins, and upon the lateral aspect of the tail; the other a comparatively large fish, attaining a length of at least a metre, without any similar development of the dermal tubercles, either in the regions mentioned or on any other part of the body. An imperfect example of the latter fish from Hichstadt, Bavaria, was originally described by Minster? under the name of Thaumas alifer, and subsequently referred by Giebel* to the existing genus Squatina. Some years afterwards a finer specimen, either of the same or a Closely allied species, from Nusplingen, Wiirtemberg, was described in detail by Fraas* under the name of Squatina acantho- derma. In 1859 the specific identity of this fish with the Hichstadt fossil was first maintained by Von Meyer ;* and still more recently the same opinion was expressed by Von Zittel,® who briefly described and figured a nearly complete example from Hichstadt more than a metre in length. Quite lately an equally fine specimen has been obtained by Mr. B. Stiirtz from the classical quarry at Nusplingen ; and it is thus possible now to compare complete examples of the fish from the Bavarian and Wirtemberg localities. Gp ig speciosa, H. von Meyer: Palontographica, vol. vii (1859), p. 4, pl. i, fig. zZ ghsioe ‘¢ Beitr. Petrefakt.,’’ pt. v (1842), p. 62, pl. vii, fig. 1. 3 Giebel, ‘‘ Fauna der Vorwelt—Fische”? (1847), p. 298. = O. Fraas, Zeitschr. deutsch. geol. Ges., vol. vi (1854), p. 782, pls. xxvii-xxix. 5 H. von Meyer, Palzontoer., ‘vol. vii (1859), p: 3. 6 K.A. von Zittel, “Handbuch der Palaeontologie,’’ vol. iii (1887), p. 92, fig. 105. DECADE IV.—VOL. V.—NO. VII. 19 290