The Lower Silurian Rocks of the South of Scotland, below the level of the Wrae Limestone of Peeblesshire, though of great thickness, and little altered by igneous agency, have as yet yielded but few of the higher forms of animal life. Two species of a phyllopod crustacean, (Peltocaris aptychoides and P. Harknessi, Salter), were discovered by Prof. Harkness, along with the first Brachiopod found in these deposits, the Siphonotreta micula of McCoy. Another crustacean of an allied genus, described by Mr. Henry Woodward, and named by him Discinocaris Browniana, was discovered last year in the neighbourhood of Moffat, by Mr. D. J. Brown. Besides the above, there occur traces of the action of marine worms, and I have, in addition, found one, possibly two, species of Lingula, a thin-walled Orthoceras, or Pteropod, and some curious spine-like bodies, probably referable to crustaceans. With the exception of these scanty remains, the strata under consideration have yielded no fossils higher in the scale of existence than Graptolites. In no other British deposit do we, however, find a greater profusion of these beautiful and characteristic fossils, or a greater number of specific types. It is the object of this communication to describe certain new forms of Graptolites which have come under my notice, together with one remarkable genus, apparently allied to the Graptolitidœ, though probably representing a different order.

The structure and marine denudation of the district between Torbay and Babbicombe Bay has been so ably unravelled by Mr. Pengelly, as to leave any other observer comparatively little to say. Among his most important discoveries must be ranked that of lithodomous perforations in limestone rocks at considerable altitudes above the sea.

By the able investigations of Mr. J. W. Salter, the various species of British Trilobites are now being systematically described, and referred to the genera to which they properly belong, the Asaphidœ with the rest; but there seems to be still some doubt as to the true differences between Asaphus and Ogygia. The feature apparently considered distinctive in the masterly work alluded to, is the form of the labrum; which, if furcate, is to be set down to Asaphus; if obtusely pointed, to be the distinguishing mark of Ogygia. How Ogygia peltata (Woodcut, Fig. 5) can be reconciled to this division, I do not see; but the main difficulty in the way of this classification is the sub-genus Ptychopyge of Angelin—distinguished by “having the facial suture within the margin in front.” This sub-genus Mr. Salter shows to be represented in Britain by Ogygia Corndensis, Murchison (Woodcut, Fig. 1): it is called Asaphus by Angelin, and has the wide axis, short and broad pleural furrows and simple caudal ribs of that genus. In addition to these features, the course of the facial suture finds a parallel' in the sub-genera of Asaphus, Isotelus, (Dekay) and Cryptonymus (Eichwald); Mr. Salter cites but one species of Ogygia that bears resemblance in this respect. Yet with all the stamp of an Asaphus, Ptychopyge Corndensis has the obtusely-pointed labrum common to Ogygia Buchii and O. Selwynii.

At a time when those curious forms often assumed by the upper beds of limestone rocks are thought worth attention, and are brought forward by some geologists as evidences of sea-action, it may not be wholly without interest if I re-introduce a curiously moulded bed of this rock, occuring near Ulverstone.

In my paper published in the July Number of this Magazine I gave a list of the Terebratulidæ from the Upware deposit; since then I have further examined them, especially with regard to the shell I named Terebrirostra neocomiensis. There are clearly certain well-marked differences between the Upware species and that fossil. The shell I called T. hippopus also proves to be a new species. Some of the specimens of the small variety of T. oblonga closely correspond with T. Fittoni of Meyer, which was described in the first volume of this Magazine; it was found at Godalming in Surrey. I have also some specimens of T. Dutempleana from the Upware bed; and I have no doubt the affinities of that shell with T. prœlonga (a species not uncommon at Upware) will be able to be determined. (See Cretaceous Brachiopoda, by T. Davidson, page 59).

A recent visit to the picturesque lake-valley of Glen-car, about seven miles N.N.E. of Sligo, has afforded an opportunity for reconsidering the method by which the fine precipices enclosing it were formed.

In the Journal of the Geological Society for November, 1866, page 463, Mr. Tylor gives a paper on “The interval of time which has passed between the formation of the upper and lower valley gravels.” He says, “Mr. Prestwich argues that, although the upper valley gravels are at a higher relative level than the lower, yet the higher series are always the older, and the lower the more modern; and we have thus the ordinary superpostion of new over old strata supposed to be reversed. This difficulty is considered by most geologists to have been surmounted by Mr. Prestwich's arguments, and his classification of the gravels has been generally accepted. My own opinion is that the evidence on which Mr. Prestwich's theory is based is insufficient.” If the gravel terraces were on one another as well as above one another, there would not only be a difficulty, but an impossibility to surmount. But the terraces are not on one another—that is, althought they are in level above one another, they are not vertically above one another. If in making a railroad cutting the sides were terraced, the upper terraces would be the first formed, and would consequently be “the older.” The lower terraces would be the last formed, and would consequently be “the more modern.” Mr. Tylor himself will allow that the upper part of a railroad cutting must be excavated before the lower part of it; and that if deposits were made during the excavation, the upper deposits would be the first made or “the older;” the lower deposits would be the last made or “the more modern.” The case is the same if, instead of the formation of a valley, and the excavators to be rain and rivers.

Some time since, my colleague, Dr. Percy, purchased from Mr. Griffiths, Some of Folkestone, and sent to me, certain fossils from the Chalk-marl near that town, which appeared to possess unusnal characters. On examining them I found that they were large scutes and spines entering into the dermal armour of what, I did not doubt, was a large reptile allied to Soelidosaurus, Hylœosaurus, and Polacanthus. I therefore requested Mr. Griffiths to procure for me every fragment of the skeleton which he could procure from the somewhat inconvenient locality (between tide-marks) in which the remains had been found, and I eventually succeeded in obtaining three teeth, with a number of fragments of the vertabræ, part of the skull and limb-bones, besides a large additional quantity of scutes. I am still not without hope of recovering other parts of the skeleton; but as the remains in my hands are sufficient to enable me to form a tolerably clear notion of the animal's structure, a brief notice of its main features will probably interest the readers of the Geological Magazine.

The Pipe-clay beds of Tipperary appear so closely to resemble in character and position the deposits of the Mountain Limestone district of North Wales and North Staffordshire, that it may not be out of place to record some observations made by Mr. C. D. Blake, on Newton Abbot, in 1862, and kindly communicated to me. There are also one or two previously published notices of these deposits, to which reference must be made.

The Geology of South Bedfordshire is now being exhibited more fully than hitherto, as the extension of the Midland Railway from Bedford to London is opening up a series of sections in the newer Seconday rocks which characterise this part of the county. The following notes were chiefly taken during a walk made last summer along the line, between the towns of Bedford and St. Alban's (Herts). For the first few miles the excavations are slight, and exhibit only the Drift sands and gravels of the rich valley of the Ouse, though these are well worthy of careful examination for flint implements and mammalian remains, which have been discovered on the north side of the river, at Biddenham, by J. Wyatt, Esq. About three miles from Bedford is an excavation in the Oxford clay; the upper portion is dark brown merging into dark blue beneath, and it abounds in fossil wood in various stages of carbonization, the colour of which ranges from brown to jet black; it is so abundant in places that some of the excavators fancied they were coming upon a coal-mine.

Since Sir Charles Lyell published his most accurate and detailed paper “On the Tertiaries of Belgium and French Flanders,” geologists could only differ in their opinions on the facts mentioned by him, New discoveries have been made in Belgium only in the last few years; besides the splendid cuttings in the ditches for the fortification of Antwerp, about which I am going to speak afterwards, there has been found, near Mons, by sinking a well, a thick bed of lime and limestone at the base of all hitherto-known Belgian Teritiary beds, containing numerous and well-preserved Tertiary marine and fresh-water mollusca. The discoverers, MM. Cornet and Briart, Engineers of Mines, and most zealous geologists, described very carefully the geological position and afterwards the extension of these lowest Tertiary beds in Hainaut. In their first paper they had tried to determine the Molluscan fauna of this basement bed, after Deshayes' works; but, out of 150 species, they could name only 22, and amongst these there are still some very doubtful ones.

Since my former communication on this subject, which appeared in the Geological Magazine for April last, (p. 154) I have had several opportunities of re-visiting some of the cuttings, on the Midland Railway, therein referred to, respecting which some doubts were expressed in reference to the age of the deposits exposed to view, and, as they are now completed, more precise observations can be made than when they were only just commenced. The cutting, south-east from Westoning, (which, in an Editorial note, was suggested might be of Tertiary age) exposes a dark heavy clay, which, upon the most rigid examination, furnished not the least trace of rolled fragments of Chalk or flints, or any other substance so frequent in the Tertiary clays of this neighbourhood, which would lead to the inference that it had been deposited subsequently to the Cretaceous era. It, however, contains what would strongly indicate that it is coæval with the Greensand, namely, a continuous band of coprolitic nodules, averaging about a foot in thickness. This layer passes through about one-third of the cutting, and may be traced from its commencement on the north-west side of the hill, passing along the face of the cutting with a gentle dip, until it reaches the level of the line, when it passes out of sight, nor does it re-appear on the south-east side of the excavation. The fossils associated with the nodules are Lamna, Belemnites, Parasmilia, and Terebratulœ, all of which are abundant in the coprolite beds at Hexton and other places in the immediate vicinity. Both above and below the coprolites the caly is identical in character, and must have been deposited eontemporaneously with its associated nodules, and, as far as I can judge, it is the equivalent of the bed h of the section given by Mr. W. Whitaker, in the Quart. Journ. Geol. Soc., vol. xxi., 1865, pp. 399, “On the Chalk of Bucks.” About the middle of the cutting is a considerable accumulation of light-brown coloured drift-sands, that lie in a basin-like hollow, that has been eroded from the summit of the hill.

The coarse ferruginous sands at the base of the Cretaceous series, in the countries of Bedford and Cambridge, have of late years attracted considerable notice, not only as sources of iron ore, but also of phosphatic matter. To these deposits the attention of geologists has been directed, and among other valuable papers, may be mentioned some by Messrs. Seeley and Walker,1 who have treated of their general physical characters, and also of their interesting fossil contents. It may be useful to some of the readers of the Geological Magazine, who are interested in tracing out the range of this deposit, and the peculiar conditions under which it was accumulated in some parts of the area, to point out briefly its characters and contents in the adjoining county of Buckingham; i.e., around Aylesbury: more especially so, as these sands have been considered to be partly equivalent in time, or the marine conditions of the Wealden and Purbeck strata.

The Rocks included under this head are those already described by Professor Phillips, in his paper “On Group of Slate Rocks in Yorkshire, between the rivers Lune and Wharfe, etc.” (Trans. Geol. Soc., 2nd Series, III. 1). Also by Professor Sedgwick, in his paper “On the Lower Palæozoic Rocks at the base of the Carboniferous Chain, between Ravenstonedale and Ribblesdale” (Quart. Journ. Geol. Soc. VIII. p. 35).

Professor Huxley's communication, relative to the discovery of a new Reptile in the Lower Chalk of the south of England, which he has called Acanthopholis horridus, may be rendered more interesting by a detailed description of its stratigraphical position and its associated organic remains, a matter of some importance in this cases, as few, if any, higher reptilian remains have occurred in the Lower Chalk of either Europe or England; whereas in the Wealden group below the Cretaceous rocks, and still lower, in the Oolites and Lias, many genera occur. The discovery by the Rev. W. Fox of a remarkable and allied reptile in 1866, from the Wealden beds of the Isle of Wight, named Polacanthus by Professor Owen, increases still more the interest of this new genus, and is another reason why it is well to understand its geological horizon.

The lower strata of the Silurian system are, as yet, but little known. The labours of Welsh and other geologists have brought to light the large fauna of the Lingula flags; but while the Upper Cambrian has thus been established and elucidated, the beds which lie immediately above it, namely the “Arenig group,” and the Llandeilo flags, remain to be searched, and a great part of the respective fauna of each to be described.

The Areing, or Skiddaw, group of Sedwick forms the base of the true Silurian rocks; it immediately underlies the Llandeilo flags, from which it is totally distinct, although caused with them in Murchison's “Siluria.”