Although the causes of the configuration of the Lake district have been discussed by Mr. Mackintosh in some interesting communications to this Magazine, and the distribution of the granite blocks from Wastdale Crag formed the subject of an able paper read by Professor Phillips to the British Association at Birmingham, 1865, the glaciation of this region seems scarcely to have attracted the attention which it deserves. In the hopes, then, that some one may be induced to do for North Wales, I venture the following remarks; although, owing to want of time and other causes, they are far less complete than I could wish them to be.

The Summit of the hill, about two miles form the station, on the property of Arthur Peel, Esq., M.P., consists of yellow and brown sand, with much iron; and the harder beds of the latter, where they form a stone, are composed largely of small pebbles of quartz, sandstone, and mica. In these the phosphatic nodules are found. Generally they lie at a variable depth from the surface—in some cases cropping out; but, in others, they prevail at a greater depth, with a capping of soft sand from three to four feet, but none have been met with below six feet from the top.

But little evidence has, hitherto, been had of the existence of large Sauroid fishes in the Kimmeridge Clay: indications by detached teeth had only, until now, reached me. The very useful “Systematic and Stratigraphical Catalogue of the Fossil Fish in the cabinets of Lord Cole” (now Earl of Enniskillen) “and Sir Philip de M. Grey Egerton,” 4to., did not include any species from that formation at the time of its publication (1837).

The district of Cleveland, long known for the beauty and variety of its scenery, has during the past few years acquired great importance through the discovery of valuable beds of iron ore in the Middle Lias. So much has been written on this district, and in a lesser degree on East Yorkshire generally, that the geological structure of this country must be tolerably well known. My object then is not so much to describe the beds as to give some notes on the physical geography of the country, explaining the relation of its present surface outlines to its internal structure, and to enquire by what means those external features have been produced.

In the former paper I adverted to the evidence which the Thames gravel afforded, that the channel in which it was deposited opened out over the Wealden area, and the corroborative evidence which the East Essex gravel furnished of a similar state of things.

Two years ago the French savans, Messrs. Lartet and Christy, laid before the Academy of Paris an account of their discoveries in the Dordogne, which proved the existence in that district of very ancient settlements of wild races of men, who kept herds of rein-deer. Since then, up to the present time, no further proofs have come to light, either in France or Germany, of the extraordinary fact that this animal—the existence of which is now limited within the 70th degree of north latitude—ever lived so far south as our own districts. The account we have now to give will probably therefore be read with great interest.

In No. VI. of the “Quarterly Journal of Science” I gave a brief account of the Trigonia semiundulata, M'Coy, MS., which has been found in certain Tertiary strata in the Colonies of Victoria and South Austraila, and which had been named, but not described, by Professor M'Coy. This species differs altogether from the recent forms, and approaches very closely in its essential characters to the members of the group “costata”, characteristic of the Oolites. It was therefore remarked, in the communication referred to, that its occurrence in Tertiary strata in Australia added another link to the chain of evidence which connects the recent fauna of that region with the Oolitic fauna of Europe. But doubt may be expressed as to the exact value to be assigned to this similarity in facies between two faunæ so widely separated in time; and it is a fair question whether the discovery of this Trigonia does not diminish, rather than add to the apparent peculiarity of the existing Australian fauna.

The great Valley of the Thames has long been known to contain deposits of gravel intermixed with freshwater beds; but the true Geological age both of the valley of its deposits was long in doubt. Latterly the view expressed by Mr. Prestwhich (in which he was of accord both with Professor Morris and Mr.Trimmer), that the whole was newer than the Boulder-clay, has met with acquiescence. The general structure of the deposits in this valley, although they form the most extensive of the Post-Glacial series in England, has not however yet been shown in any comprehensive manner.

Amongst the many objects of interest to the naturalist in that remarkable limb of the Western Highlands, variously written “Cantyre,” “Cantire,” or “Kintire,” are the raised beach and seaworn rocks which may be traced all along the coast under varying forms and aspects. This beach is the same as that which has been described by various writers as skirting the coast of Scotland from the Roman Wall northward, and winding through the innumerable fiords and sea-locks of the Firth of Clyde and the western coast; and to which attention was first called, I think, by Mr. Smith of Jordanhill, in 1836 and 1838, in papers read before the Geological and Wernerian Societies, and with other memoirs condensed into a small volume, in 1862. It is the last and by far the most strongly pronounced of all the raised beaches of Scotland—of which there are several—and is very graphically described by Mr. Geikie in his recent work. Now it is worthy of remark, that each of these authors draws opposite conclusions regarding the age of this raised beach from the same evidence; for Mr. Smith, of Jordanhill, considers the beach to be more ancient than the Roman period, and Mr. Geikie, on the contrary, more recent, both appealing to the position of the Roman Wall at its termination on the western and eastern coasts as evidence of the correctness of their views.

The Upper Llandeilo Rocks of the South of Scotland have long been known to yield graptolites in great profusion, few other forms of animal life being recognised as occuring in them. Having, this summer, had an opportunity of examining the graptolite-shales of Garple Linn, near Moffat, I was struck with the occurrence in them of numerous bodies, differing from the graptolites in form, though resembling them in mineral texture.

Mr. Mackintosh (Vol. III., p. 69, and p. 155, of the Geol. Mag.) adduces the preservation of numerous terraces on the hill-sides in the Cretaceous districts of ‘Wilts. and Dorest,’ as “evidence of limited subaerial denudation since those terraces were formed,” for that they are “raised sea-beaches,” he says, admits of no doubt.

The generic name of the Sauroid Fish, here indicated by portions of jaws, relates to the unusually well-marked arrangement of the teeth on the dentary bone in two almost parallel ranks along the whole of its alveolar border. The outer rank (Plate V. fig. 1) consisting of few and large teeth; the inner rank of small ones in greater number.

In a paper in this Magazine, upon the structure of the Thames Valley, I endeavoured to show that instead of being, as had been asserted, a valley of similar structure to those of the Somme and Seine, and containing deposits of nearly similar order and age, the valley in which the Thames gravel was deposited possessed no outlet to what is now the North Sea, being divided from it by a range of high gravelless country; and that, in lieu of such an outlet, the valley opened, in more than one part, over what is now the bare Chalk country forming the northern boundary of the Valley of the Weald. I also endeavoured to show that all the deposits of the Thames Valley, except the peat and marsh clay, belonged to several successive stages, marking the gradual denudation of the Boulderclay, the lower Bagshot, the London Clay, and the subjacent Tertiaries, which had, at the end of the Glacial period, spread over the south-east of England in a complete order of succession: the sea into which this valley discharged occupying, what is now, the Chalk country of the Counties of Kent, Surrey, Sussex, and Hampshire, inclusive of the interval subsequently scooped out to form the Valley of the Weald: so that, not only was the latter valley newer than that of the Thames, and of the most recent of the Thames Valley deposits, except the peat and marsh clay, but that these deposits in themselves marked a long descent in time from that comparatively remote period of the Boulder-clay.

The article by Mr. Mackintosh on “The Cliffs, Gorges, and Valleys of Wales,” in the September number of the Geological Magazine, raises so many questions in opposition to the views I endeavoured to support in the previous number, that I venture to offer a few further observations on some of the more salient points in which Mr. Mackintosh differs from the advocates of subaërial denudation.

The unsatisfactory condition of palæontological botany arises from the imperfect materials which are obtained from the earth's strata. With the exception of two or three remarkable structures, no histological characters have been found whereby the position of a plant can be determined from an examination of its woody structure; so that silicified or calcified woods, which are far from rare, supply little more information than that they are portions of a vascular cryptogam, a palm, a conifer, or other exogen. Of leaves also it may be said that, while a very few natural families have characteristic forms, yet leaves which are undistinguishable are found belonging to plants widely separated in the vegetable kingdom, so that we have little confidence in determinations made from them; indeed, such determinations must be consideredat the best but as guesses at the truth, and these can seldom go further than the natural order, or, perhaps, the genus towhich the fossil belongs. To manufacture species on no other characters than those obtained from slight variations in the form of the leaf, is a reckless multiplication of names, condemned not only by the botanist, but by every one who has carefully examined the variety in form and venation that exist among the leaves of a single shrub or tree. The organs employedby systematists in the classification of plants are so delicate, and so easily perish, that they are very rare as fossils.Fruits, however, are more abundant, and after the flower they may be held of next value in determining the affinities of aplant. Even the separated seeds of living species, or members of living genera, can be positively determined; but when the affinities are obscure, the more or less imperfect specimens of fossil seeds detached from their fruits are very unsatisfactory materials.

In a former article I endeavoured to show that the more abrupt inequalities of the earth's surface, so far as they consist of escarpments with their associated phenomena, are chiefly due to the former action of the sea. Before proceeding to consider the origin of Valleys, I find it necessary to refer to a statement I made in the last article about Raised Beaches (page 69). My object was merely to show that the preservation of numerous terraces in the Cretaceous districts of Wilts and Dorset furnished an evidence of limited subaërial denudation since these terraces were formed. The terraces to which I alluded, principally occur at comparatively low levels; and that they are raised beaches can, I think, be clearly proved. But this is not necessary, so far as the present controversy is concerned; for the preservation of terraces in gravel (more easily worn away than chalk, according to the subaërialists), which all admit are either raised sea-beaches, or glacial-lake-beaches (such as those of Glenroy), afford an equally convincing proof of the impotence of rain as a denuding agent.

Lough Corrib is a long irregular lake of various widths, but having a general bearing of about N.W. and S.E. Its N.W. portion is in a granite and metamorphic rock country, while the rest of it overlies Carboniferous rocks, principally limestone. The northern portion is deep, the southern shallow, and through the whole of it are scattered numerous islands which, in the former part, are generally composed of Boulder-clay, while those in the latter portion are nearly always rock. Its known natural outlets are two, one being over the barrier of metamorphic rocks at Galway (U on Map, Pl. XIX), and the other subterranean passage south of Castlegar (T on Map, Pl. XIX). On all sides of the lake are rocks extending under it, or, to use Professor Ramsay's term, it lies in a “Rock-basin.” What excavated this Rock-basin? I propose in this paper to consider.

As every part of the crust of the earth has at one time been the surface, it follows that all questions connected with the origin of the present “form of the ground” must be very impotant, and that on their issue the progress of Geology must in a great measure depend. But on this subject a very wide difference of opinion at present exists. According to one party, consisting of Professor Ramsay, Mr. Jukes, Mr. Geikie, Colonel Greenwood, Dr. Foster, and others, the more abrupt inequalities of the earth's surface have been produced by subaërial or atmospheric causes. According to the other school, embracing Sir Charles Lyell, Sir Roderick Murchison, Professors Sedgwick and Phillips, Mr.Edward Hull, etc., the sea has been the principal denuding or excavating agent.

Mr. Prestwich has, in two valuable papers, published by the Geological Society, given a very detailed description of a raised beach and associated recent accumulations, upon the coast in the vicinity of Sangatte, a village about five miles from Calais. In the second of these papers, the author mentions that he proceeded round the headland called Cap Blanc-nez, for the purpose of ascertaining whether any traces of a similarly recent formation were to be observed in the bay of Wissant, and that his search, as far as he went, was fruitless; “but,” he adds, “owing to the extent of the dunes around Wissant, such a beach might be entirely hidden by the sands.”.

Of the various geological evidences inferring a vast duration of the existing contour and conditions of surface since the latest marine submergence, there is, perhaps, none more striking than the accumulation of great masses of Tufa charged with recent organic remains.