is by no means put forth as perfect in all its parts, but simply as embodying what I conceive to be, for reasons already assigned, as close an approximation to a natural arrangement of the Rhizopods as the present state of our knowledge allows and that, having done my best during the course of the past twelve years to test it whenever opportunities occurred, I have not been able to detect any serious flaw in it. It must nevertheless be accepted merely as an attempt to reduce the group of organisms in question to something like natural order.

SUPPLEMENTARY NOTES.

Contractile vesicle.-It has always been urged by me that there is more reason for regarding the contractile vesicle of the Rhizopod as an organ whereby the effete residue of the watery fluid absorbed by the animal is first collected, and then discharged by an orifice in the vesicle, extemporized at the moment of extreme dilatation, than for regarding it as a circulatory organ. I may therefore be allowed to point out that although the nature of this organ was discussed by me in detail in the Annals' for December 1863, and it was there shown (both on the independent evidence of my friend Mr. Carter, and as the result of my own observations) that the contractile vesicle in Amaba, Actinophrys, and certain Infusoria discharges its contents at the immediate surface of the animal's body (my description of the process being accompanied by illustrative figures), Dr. Carpenter has not scrupled to say, at p. 472 of his work 'The Microscope' (5th Edit. 1875), that the nature of the process was for the first time fully established by Dr. Zenker in 1867"-and this in the same page in which he shows that he was acquainted with my series of papers in the 'Annals' upon the Rhizopods, in which the observations were recorded.

เ

Noctiluca. In the Report of the Challenger' Expedition, published in the Proceedings of the Royal Society, 1876, vol. xxiv. pl. 21, there are three figures which are described as representing "true Diatoms," to which the generic name of Pyrocystis has been given by the discoverers. am, indeed, grievously mistaken if these structures bear the slightest affinity to Diatoms, or are any thing else than true oceanic Noctiluca. It would be just as irrational to separate the testaceous from the naked Rhizopods, because the former have hard coverings and the latter have none, as to regard these new forms as distinct from Noctiluca, because they present a delicate siliceous wall. The figures of the elongate form, if accurate representations, as they doubtless are,

show at a glance that the structure is not that of any Diatom.

Dr. Gwyn Jeffreys's Report on the 'Valorous' Expedition (Proc. Roy. Soc., June 1876, p. 228), there is an account of some Diatoms examined by Professor Dickie, it being mentioned incidentally that along with these "were two Polycystina, namely Dictyocha fibula, Ehr., and Dictyocha gracilis, Ehr." With all deference to Prof. Dickie, I beg leave to point out that the Dictyochide are neither Diatoms, as they have been regarded by some writers, nor Polycystina as they would now appear to be regarded by others. They are Rhizopods, holding an intermediate place between Thalassicolla on the one hand, and the siliceous sponges on the other; and hence (as was long ago shown by me) they constitute the true connecting link between the Rhizopods and the Sponges. The basket-shaped framework of the living Dictyocha is never single, but invariably double, the concavities being placed face to face, and the two portions retained in position solely by the sarcode body, which fills and surrounds them. The distinct nucleus may always be seen, in recent specimens, suspended as it were in the middle of the sarcode, half within the boundary line of one framework, half within that of the other. The most remarkable feature, however, of Dictyocha, and the one which at once establishes its alliance with the siliceous sponges, is that every part of the siliceous framework is tubular.

BIBLIOGRAPHICAL NOTICES.

By

The Primeval World of Switzerland. With 560 Illustrations. Professor HEER. Edited by JAMES HEYWOOD, F.R.S. &c. 2 vols. 8vo. Longmans & Co.: London, 1876.

The Geology of England and Wales. By HORACE B. WOODWARD, F.G.S. &c. With coloured Geological Map and numerous woodcuts. 8vo. Longmans & Co.: London, 1876.

ENGLAND and Wales have been said to exhibit an epitome of geology to the student of successive rock-formations and fossiliferous strata. From the oldest and lowest, or nearly lowest, known series of rockmasses, now much altered, to the latest or uppermost deposits of sea, lake, and river, some representative rock or layer is found in place, indicating period after period of the earth's history, as far as geologists can recognize its terraqueous existence.

Switzerland also presents an epitome of the geological history of

the world-except, 1st, that the oldest portion of the record is obscured to a greater extent by the change of strata into crystalline rocks, and, 2ndly, the marine formations of the latest period are wanting in this inland region.

As different books of history, having the same basis of facts, vary in their style and appearance, treating the subject-matter broadly or succinctly-forming a simple plain volume, or appearing with sensational pictures and embossed binding, so the first-mentioned of our natural epitomes of geology has its leaves and chapters plain and unbedecked, carrying on the student quietly from stage to stage, with but few outbursts and disturbances of events; whilst the latter, beginning with the results of great changes and bouleversements, has often great events to speak of, fuller series of events to describe, and better-known communities of life to introduce to notice.

The mountains, gorges, valleys, lakes, and rivers of Switzerland astonish or vaguely interest the mere tourist, give studies of lights, shades, and distances to the artist, offer many problems in physics to the exact inquirer, and, while presenting difficulty after difficulty to the geologist, at the same time help him to unravel the intricate and solve the doubtful in their structure, and thus open out the succession of events, not only among these crumpled and riven mountains, but in the gradual formation and changes of strata all over the world.

After the long series of labours carried out by eminent savants, numerous geological sections have been drawn across Switzerland, and excellent maps have been constructed. The more easterly Alpine districts also have been explored and explained by these geologists. Prof. O. Heer, in the work before us*, illustrates the old geography and hydrography of Central Europe, and its old lifegroups, during successive periods, from the Carboniferous to the Quaternary, taking the known stratal conditions and collected fossils as the basis of his animated descriptions and of the pictorial illustrations with which his work is ornamented.

The oldest and much-altered rocks are known as crystalline and metamorphic, and, although now schistose, gneissic, and granitic, are referable probably to the Devonian, Silurian, and Cambrian systems, if not to the Laurentian also. They form axial masses, longitudinal and otherwise, in many parts of the Alps, having been not only folded but intensely crumpled strata, low-seated, crushed, chemically altered, and ultimately forced to a higher position by the great lateral pressure to which the whole complicated mountainmass or massif was subsequently subjected. They have been here and there exposed by the destruction of the overriding schists and strata; and then they stand out as peaks and ridges, or even great rounded bosses, according to their relative hardness, and according

*The Editor states that the German and French editions were both placed in the hands of W. S. Dallas, Esq., F.L.S., for translation, and that thanks are especially due to that gentleman for the care he has bestowed on natural-history details.

as their structure is massive or laminated. Of the seas in which these oldest rocks originated, of the life-forms inhabiting the waters and lands of their times, Switzerland gives no evidence. Their hidden story is to the rest of the geological record of the Alps what the mythic period is to any human history. Everyday affairs in the one, and organic and inorganic processes in the other, may have been conducted on the same principles as at present; but the details have been obscured and are irrevocable.

The strata formed in the Carboniferous period have in many places participated in the successive foldings and squeezings of the mountain-masses; and the coal has been changed into anthracite. Much, however, remains sufficiently unaltered, in the Lower Valais and elsewhere, to supply evidence that the crystalline rocks of the Central Alps had been raised above the sea at the Coal-period, that the corals and shells are those of the Mountain-limestone elsewhere, and that the jungles and forests, which were converted into seams of coal, consisted of the great trees of the Clubmoss family (Lycopodiacea), the gigantic Calamites, and the manifold Ferns, which grew so abundantly at that time in nearly every region of the world. In Chapter I. Prof. Heer discourses with knowledge on the origin of coal, and of analogous formations of peat, paper-coal, and lignite, and on some of the plants and insects found in the shales of the Coal-measures. The succeeding Permian (or Dyas) series is represented by red sandstone, with breccia, in the valley of the Sernft or Sernif. This rock, termed Sernifite by M. Heer, contains copper-ores, as usual with rocks of that age.

The Swiss Saliferous formation is the subject of Chapter II. Here the origin of rock-salt by the desiccation of shallow seas is briefly discussed, and the Swiss salt-works described. The fossils of the Muschelkalk and especially the fossil plants found in the Keuper (Plates II. & III.) are treated of.

Chapter III. elucidates the history of the Liassic strata (the Black Jura of the Germans) occurring at Schembelen in the Canton of Aargau. An analogous recent formation is described as taking place at the Gongulho, Madeira. What kind of creatures the Liassic fossils once were is shown by the study of the shells, crustaceans, fishes, seaweeds, land-plants, and insects. Among the last are Cockroaches, Grasshoppers, Earwigs, Termites, Dragonflies, 114 species of Beetles (comprising such as feed on wood, fungi, leaves, flowers, dung, and carrion, and on insects and other small creatures, showing the contemporary existence of a multitude of terrestrial organisms), also Water-beetles and some other insects. Figures of many fossils determined by M. Heer are given in Pls. IV.-VIII. Some comparisons are offered of the Liassic fauna of Switzerland with that in other countries. The extent of the marine areas of the Lias and their warm climate, the fertility of the Lias and its hydrocarbon products are also noted.

The Middle and Upper Jurassic Formations ("Brown" and "White Jura" of the Germans, "Oolites " of the English, &c.) are treated of in Chapter IV,, which is full of interesting information

as to Coral Islands, Coralline Limestone, and minute marine organisms of these old strata, with Sea-urchins, Ammonites, and other Shells, Turtles &c., and Seaweed. The Land-plants, Insects, and unique old Bird of the Jurassic period also occupy attention.

Together with a general table of the Swiss "Jura" (pp. 152-4), a more detailed account of the successive stages is given; also a rough chart of the Jurassic Sea in the European area, and some notes on the economic products of the Jurassic rocks.

66

In sketching the features and history of Central Europe during the Cretaceous Period, in Chapter V., M. Heer shows, with the help of another little map *, the changes which had taken place in the shape of the lands, from the alteration of levels and coasts. With these changes, in the course of ages, the fauna and flora also were greatly modified by variation of species or transmutation of organic forms." The Cretaceous Cephalopods, carefully tabulated at pp. 183 & 185, are used as terms of comparison in showing the relationship of different Cretaceous areas in Europe. Other fossils are noticed, especially Seaweeds, Diatoms, Foraminifers, Echinoderms, Mollusks, &c. The distribution of Land Plants in the Cretaceous period is described with M. Heer's accurate knowledge of multitudinous specimens found in Europe, Greenland, North America, and Tropical Africa (Chargeh, west of Thebes).

The Eocene formation in Switzerland (Chapter VI.) comprises :the curious Glaris slate, yielding many fossil Fishes, some Turtles and Birds; the Flysch, with its characteristic Fucoid remains and imbedded blocks of granite; the Nummulitic Limestone, containing an extensive marine fauna; and the local pea-iron-ore (Bohnerz), with mammalian bones.

The Miocene or Molasse Period of Switzerland (Chapter VII.) flourished when the land in what is now Central Europe had greatly increased, by the gradual uprising of the Alpine and other districts. Lakes had been formed, the recipients of much vegetable matter; volcanoes burst out here and there; and great accumulations of gravel were formed by mountain-torrents, and of shingle by the sea, during oscillations of land. The Miocene Flora, preserved in the lignites and plant-beds of the period, whether at home or in England, Greenland, Spitzbergen, or North America, has been a favourite study with M. Heer; so also has the Insect-fauna of the same period, at Eningen especially, where well-preserved remains. of Mammals, Birds, Reptiles, Amphibia, Fishes, and other creatures also abound. These are vividly described in Chapters VIII.-XI., and comparisons are made with those of other countries. Descriptions of special localities rich in these fossils, and philosophic considerations on the probable climate of the Miocene Period, are also given. The principal results of this investigation are stated

Like the Jurassic map above mentioned, and others that follow, this is an improved portion of one of the late M. Elie de Beaumont's palæogeographical European sketch maps.