Through the generosity of Mr. W. Hill, the Museum of Practical Geology possesses a tooth found in the “Totternhoe Stone” in the -neighbourhood of Hitchin, which is of especial interest inasmuch as it is undoubtedly closely related to Iguanodon, and is of later date than any British Dinosaurian remains hitherto recorded; the Acanthopholis horridus of Prof. Huxley, from the Chalk Marl, and the Trachodon (Hadrosaurus) Cantabrigensis, of Mr. Lydekker, from the “Cambridge Greensand,” being, up to the present time, the most recent of known British Dinosaurs. Remains of allied forms, however, have been found at a higher horizon of the Chalk of Maestricht, and have been described by Prof. Seeley, and M. L. Dollo.'

In submitting the following paper to the readers of the GEOLOGICAL MAGAZINE, I am conscious that some apology is needed for entering upon so difficult a subject. My position is as follows:—In 1879 the late Mr. E. B. Tawney joined me in the investigation of a series of detached blocks trawled from time to time by the Brixham fishermen. The character of certain of these stones having suggested to Mr. Tawney the idea that the schists of South Devon might possibly be of pre-Cambrian age, he visited the district in 1880, with the expectation of being the first to advance that hypothesis. The evidence of the schists themselves failed to satisfy Mr. Tawney on the point in question, and his premature death prevented his attacking the problem on a subsequent occasion, as he had hoped to be able to do.

So much attention has been bestowed of late years on fossil organic remains from rocks of all ages, that it must appear surprising to find so little notice has been directed to the Insectremains from the British Secondary rocks.

It is now nearly fifty years since that veteran geologist, the Rev. P. B. Brodie, M.A., F.G.S., published his modest little 8vo. volume entitled “A History of the Fossil Insects in the Secondary Rocks of England” which is still the only separate work of the kind extant. Numerous Insect-remains have, it is true, been described by Prof. J. O. Westwood, Mr. H. E. Strickland, Prof. J. F. Blake, Mr. A. G. Butler, and Mr. S. H. Scudder, from English rocks of Secondary age; and Mr. Herbert Goss has given an excellent summary of our knowledge of the Mesozoic Insects in the Proceedings of the Geologists' Association (1879).

It has long been known that the Coniston Limestone Series of the English Lake District and surrounding areas is separable into minor divisions. As a knowledge of these will prove useful in settling the question as to the exact relation between the Couiston Limestone beds and the underlying rocks, no apology seems needed for giving a detailed account of the rocks of this series.

The literature of the subject is extensive, but we fortunately possess an excellent bibliography of works referring to the geology of the Lake District, in the appendix supplied by Mr. Whitaker to the late Mr. Ward's Memoir on the Geology of the Northern Half of the English Lake District.

Professor James Hall's discovery, in 1864, of his remarkable genus Trematonotus, in the Niagara rocks of North America, formed an interesting and valuable addition to his researches in conchological science.

The special features of this shell consist in its Bellerophontoid appearance, coupled with the presence of a single row of isolated perforations on the central part of the dorsal surface. It was somewhat erroneously regarded by its author as a sub-genus of Leveillia (Porcellia), though its unique characters would mark it as a distinct form, and probably more intimately related to the well-known Haliotis of our modern seas than to any other known shell.

In the summer of 1891 a journey was undertaken by the writer to the S.W. Governments of Russia, the immediate object in view being the study of the geology of that region. This portion of the notes then taken will deal more especially with the extent, thickness, and general contour of the Cretaceous beds of the district, together with a review of the Eussian literature bearing on the zonal distribution in the various Governments.

In 1845 Murchison had gathered together most of the facts then known regarding the Cretaceous formation of S. Russia, but his own direct observations were few, and the work was considered of only secondary importance. Under these circumstances it would not have been very surprising to find that he had fallen into error on many points.

In comparing the quartz-schists with the Devonian sandstones, or grit-bands, several original minerals can be traced from the one to the other, e.g. tourmaline, mica, and at least two quartzes. In the case of the Green Rocks and Devonian Volcanics we are met at the outset with the difficulty, that not a grain or crystal of an original mineral has been recorded with confidence as occurring in the metamorphic Green Rocks; though there seems to be little doubt that the latter are often metamorphosed diabases.

Early in the year the present writer published some notes on the Lower Devonian Fishes of Campbellton, New Brunswick, collected by Mr. Jex in the summer of 1891. Since that date the remainder of the collection, comprising a very large series of specimens from the Upper Devonian of Scaumenac Bay, in the Province of Quebec, has been acquired by the British Museum; and materials are thus forthcoming for some further observations.

During the last two years four papers have appeared upon the Australian Cainozoic Echinoids, contributed by M. Cotteau, Prof. R. Tate, Herr A. Bittner, and myself. These add considerably to our knowledge of the fauna; they show that it is Eocene and Oligocene, instead of Miocene, and that it is remarkably varied and rich in genera. I am now able to add one or two more species to the list, and at the same time take the opportunity of referring to one or two changes proposed by Prof. Tate and Herr Bittner.

The Lower Devonian Fish-Fauna of Campbellton, New Brunswick, has already been described by Mr. Whiteaves, of the Canadian Geological Survey, and Dr. Traquair, of Edinburgh; and a few supplementary observations are published in the British Museum Catalogue of Fossil Fishes, Part II. (1891). Much, however, still remains to be learned concerning the skeletal anatomy of the genera and species already determined; and many types of early fishes will doubtless soon be discovered by future explorers of the formation and locality in question. A new series of specimens just received by the British Museum from Mr. R. F. Damon, of Weymouth, adds some small items of interest to our knowledge of the subject; and the following notes relate to the advance thus made. The fossils under discussion were collected last summer by Mr. Jex, and are all much crushed and flattened in the usual manner.

During the past autumn, at the kindly suggestion of Prof. Baron von Bichthofen, I spent some months in the study of the strata and fossils of the neighbourhood of St. Cassian. My object was to endeavour, if possible, to determine the most natural subdivisions of these classic strata, and to fix their characteristic fossils. As the results I have obtained are somewhat novel, and may prove of interest to those who are familiar with the enigmatical character of the stratigraphy of the beautiful region of the Dolomites, I may, perhaps, be permitted to give in this place a short summary of my conclusions, in anticipation of a detailed paper upon the subject.

In the “Catalogue of Fossil Fishes in the British Museum“ (pt. i. 1889, p. 76, pl. iii. fig. 1), the imperfect rostrum of a Selachian fish from the Upper Cretaceous of Mount Lebanon was described under the new generic and specific name of Sclerorhynchm atavus. Presenting some resemblances to the rostrum both of the typical saw-fish (Prislis) and of PristiopJtorus, hesitation was expressed in determining the systematic position of the genus to which the fossil pertained; but from the apparently complex nature of the rostral cartilages and the absence of extended prepalatines, it was deemed advisable to place the fish provisionally in the family of Pristidæ.

The occurrence in the Ledbury “Passage-beds” of a united series of teeth referable to the American type of fossil fishes named by Prof. Newberry Onychodus, was made known by Mr. A. Smith Woodward in the GEOLOGICAL MAGAZINE for November, 1888; and in the British Museum Catalogue in 1891. Since then I have met with another example of the genus among the stores of the Geological Survey, which, as it seems to be quite distinct from the Herefordshire species, and is from a distant locality, deserves to be placed on record.

The Landscape Marble or Cotham Stone is one of the best known of our English ornamental rocks. Polished slabs of it may be seen in most museums; and there are fashioned out of it paperweights, ring-stands, and other useful objects, which may be purchased on Clifton Down and elsewhere.

This stone came into notice when it was quarried, together with other beds, near Cotham House, on the northern side of Bristol; and it was described in considerable detail in 1754 by Edward Owen, who then gave it the name of “Cotham Stone.”

It is a hard, close-grained argillaceous limestone, which breaks with a fracture almost as conchoidal as that of flint; and it is characterized by dark arborescent markings which pervade the stone. These markings rise from a more or less stratified base, and terminate upwards in the wavy banded portion of the limestone, which varies from one to about nine inches in thickness. Thus when slabs, cut at right angles to the planes of bedding, are polished, there may often be discerned (with the aid of the imagination) a landscape with a prominent row of trees and bushes, with clouds above, and perhaps the semblance of water in the foreground.

In the Quart. Journ. Geol. Soc, vol. xxxvi. 1880, p. 617, Mr. John B. Marr mentions having examined three specimens of a Phyllopodiform Crustacean discovered by Mr. Martin Dusl in the strata of “Colonie Haidinger,” situated not far from the village of Gross-chuchle, south of Prague.

The specimens were then identified with Discinocaris Browniana, H. Woodw., figured and described in the same Journal, vol. xxii. 1866, p. 503, pi. 25, figs. 4, 5, and 7. They are also mentioned by Dr. H. Woodward and Prof. T. Eupert Jones in the Third Eeport of the Committee on the Fossil Pliyllopoda of the Palaeozoic Eocks, 1885, p. 2, under Mr. Marr's specific determination.

In the course of a visit to the Hunsruck district between Treves and Bingen in the spring of 1890, in company with Professor Gosselet, Mons. C. Barrois, Herr von Eeinach and Herr Grebe, I was struck by the resemblance displayed by the Permian quartz porphyry of the valley of the Nahe, between Birkenfeld and Bingen, to fragments contained in the breccias of Teignmouth. In discussing the South Devon section with the two gentlemen last named, on that occasion, they both gave it as their opinion that the lower beds of the Devon section might prove to be representatives of the Bothliegende.

The beds above the Borrowdale volcanic group, and below the Coniston Flags, have been treated, in detail in other communications, but, notwithstanding all that has been written of the higher Silurian rocks of the Lake District, something remains to be said about them.

Although the old-fashioned ideas as to the association of different minerals held by Breithaupt and others have been found to require much modification, there are still certain rules which hold with a high degree of generality. They are, indeed, merely consequences of the principle that the most important of the factors which determine the mineralogical constitution of an igneous rock, is the chemical composition of the magma from which it is formed. Roughly speaking, we may say that original free silica and acid silicates occur characteristically in acid rocks, more basic silicates in basic rocks.

Having sifted the evidence in so far as it is available in Scotland and the North of England, we will now advance further south; and first in regard to the Eastern Counties. Here as elsewhere it is unfortunate that we so very seldom can find the beds upon which the solution of the problem depends in actualcontact so as to apply the only real test, namely, that of superposition. When we can do so, it seems to me the case is conclusive.

Mr. Marr's valuable communication on the Coniston Limestone Series, which appeared in the March Number of this Magazine, is sure to be welcomed as an excellent summary of the geology of this interesting group of rocks. It contains a digest of most of the published work relating to the Coniston Limestone Series, and also many new facts and arguments drawn from Mr. Marr's own observations in the field.