any obstacle in the way is surely to be lamented, and especially obstacles so serious as those alluded to, as regards invalids. In sailing ships, West Indiamen, attention is nowbeing paid to ventilation :-improved methods have been introduced in many of them; and on this account, and on account of the convenience and comforts they afford, they are preferred by some passengers, notwithstanding they are commonly nearly twice as long in making the homeward yoyage. The competition should have the attention of the Managing Committee, or the Directors of the Company, who, could they secure comfort as well as speed, in the transit, might rest secure of their vessels having the preference, at least in the great majority of instances.

I am sure your humanity will find an excuse for these latter remarks, which I offer with the hope that they may meet the eye of some influential person belonging to the Company, well disposed to have the West India Mail Steamers made as comfortable and as wholesome as possible for passengers, and as profitable as possible to the proprietors, a union of interests much to be desired. I remain, my dear Sir, with much esteem, faithfully yours,

J. DAVY.

TO PROFESSOR JAMESON, Edinburgh.

New Considerations on the Paleontology of Auvergne.
By A. POMEL.

The numerous fossil bones contained in the formations of Auvergne have already been either described or mentioned by many authors; but they have too often been contented with superficial and incomplete researches. Some have neglected to study carefully the different deposits in which they lie, and others have inconsiderately established ill-defined species on mere individual variations. M. De Blainville even, in his beautiful and classical Osteographie, has often allowed his mind to be pre-occupied with theoretical notions which he still maintains, almost alone against all other palæontologists,

and he has not given the necessary care to geological indications. Now, it is only by introducing an extreme degree of precision into the zoological analysis of characters, and the geological study of formations, that palæontology can find that solid and lasting foundation of which the precipitation of some individuals has sometimes deprived her.

M. Pomel, in the two memoirs with which we are acquainted only by an extract, and which we hope will be laid immediately before the public in extenso, shews that, in the deposits of the basin of the Allier, there are three different ages, which prove that three very distinct faunas have succeeded each other since the commencement of the tertiary epoch, in this which corresponds at present to Auvergne. The oldest of these faunas belongs to the miocene epoch, and is contemporary with that of the faluns of Touraine, the sandstones of Fontainbleau, &c. It is characterised by numerous lost genera.

The second fauna, which M. Pomel considers more particularly in his first memoir, belongs to the pliocene period. . The organic remains of the animals which compose it have been preserved in the most ancient deposits of the pumice conglomerates, chiefly at the foot of Mount Perrier. The genera, for the most part, belong to the existing fauna, but the species are all extinct. We may mention, in particular, the Canis megamastoides, the Ursidae, Mustela lutroides, Lutra Bravardi, the Hyæna of Mount Perrier, the genus Stenodon, a Mastodonte, a species of Rhinoceros, tall and slender, a Tapir, numerous species of Deers very different from those now living, small Oxen, high on their legs, &c.

The third fauna, which has been too often confounded with the second, belongs entirely to the diluvian epoch. The bones are preserved among the debris at the base or the sides of hills, under lavas, in fissures, in the travertins and mud of certain grottoes. The deposits containing them are scattered over a multitude of localities, chiefly in the valley of Limagne. The animals composing this fauna belong, in great numbers, to the existing species. Dogs, martins, otters, &c., cannot be distinguished from those now living; cats replace the stenodons; there is no mastodons, and the elephant supplies

its place; the rhinoceros is the Siberian species (R. tichorhinus). The oxen exhibit the heavy forms of the present kinds; the horse and hippopotamus supply the place of the lost genera. The Deers greatly resemble those of our own times, &c.

M. Bravard (Bull. Soc. Geol. iii., 197,) has attempted to distinguish two distinct faunas in this epoch, and he separates the elephantine fauna contained in the more recently formed lands of Champeix, Veneix, Tour de Boulade, &c., from the diluvian fauna contained in the caverns or fissures of Coudes, and the sub-volcanic'alluviums of Neschers. The investigations of M. Pomel seem to prove that there are not grounds for maintaining this division.

The resemblance between the species of M. Pomel's diluvian epoch and those of the existing world, seem to me to furnish a new and powerful argument in favour of the opinion which I expressed, (Traité Elem. de Paleontologie, tom. i., note B,) that the diluvian epoch is connected without interruption with the modern epoch. It was not, therefore, without surprise that I saw M. Pomel conclude by saying that it is impossible for him to admit my opinion on this subject. I am certain that if this skilful geologist ágain examines the question, he will find, according to his own observations, 1st, That the majority of the species of the diluvian epoch have not been destroyed at the end of that epoch; 2dly, That there has not been a sudden appearance of an entirely new fauna at the commencement of the modern epoch; 3dly, That between the diluvian and modern epoch there has been no event which has acted on organisation in the same manner as those which have separated the tertiary epoch from the diluvian epoch, the cretaceous epoch from the tertiary, &c. ; 4thly, That consequently the diluvian and modern epochs are not separated by characters similar to those which separate the other geological epochs. M. Pomel may the more readily admit these conclusions, since he insists, with reason, on the fact that the gravels of the diluvian epoch have not been deposited by a decisive and instantaneous phenomenon, but rather by a series "of small successive local inundations which could not operate at the same time, and that there was

a long diluvian epoch which might more properly be called alluvial, since the latter name has a more general acceptation, and may be applied to diluvium, which is only an exaggerated paroxysm of this great period."

There is another fact in M. Pomel's memoir, which ought to be of great interest to geologists at a time when the attention is so actively directed to all that relates to glaciers. During the diluvian epoch, that is to say, during the period when the glacialists suppose that the extension of the glaciers round the Alps was much greater than it now is, animals. lived in the centre of France which are now banished to the coldest regions of our hemisphere. The reindeer, the lagomys, the spermophilus, rarely the glutton, &c., seem by their presence to justify the hypothesis that the climate of central Europe has been for a time colder than at present. It is true, adds M. Pomel, that we have not yet found any geological traces of the existence of glaciers in Auvergne, although this country presents very elevated mountain summits.

The second memoir is devoted to the study of the miocene epoch in the basin of the Allier. After giving a geological sketch of the constitution of the deposits in the valley, M. Pomel considers the vertebrate animals composing the fauna of this remarkable period. Among the carnivora he particularly notices Amphicyon minor, a dog with a short head, which appears to have wanted the second lower tubercular; two civets (Viverra antiqua, Blainv. and primava, Pom.); the Plesictis genettoides (Mustela plesictis, Delaizer and De Parieu), which forms a genus intermediate between the martins and genettes; Lutra Valetoni, (Geoff. St Hil.); Meganthereon brevidens, a remarkable species belonging to the tribe of cats, and which ought to be united to some other species of Europe. and America, in order to constitute a genus which has already received the names of Meganthereon, Stenodon, Machairodus, and Trepanodon; and a Pterodon, an anomalous genus probably belonging to the subclass Didelphi.

The Gnawers are numerous, but as yet little known. M. Pomel mentions Steneofiber, Archæomys, and the Rats.

In the division of Pachyderms, we find the Dinotherium giganteum; a tapir of small size and slender limbs (Tapir Poi

rieri); some Rhinoceros, not yet well determined; many Anthracotherium; and the genus Cainotherium, Bravard, (Oplotherium, Delaiz.), which connects the Anoplotherium with the Ruminants.

The Ruminants present many species of Amphitragulus, a new genus of the family Moschus, and which, in its dentition, has relations on the one hand with the Llamas, and, on the other, with the Anoplotherium. Some bones not well known and described under the name of Dremotherium, are likewise referred to in the order of ruminants.

The Birds have not yet been determined. The bones of of palmipedes, waders, and birds of prey, have been found. Among the Reptiles, M. Pomel mentions a land tortoise (Testudo gigantea), two emydes, an emysaurus (E. Meilheuratio), a trionyx, a crocodile (C. Ratelii), a Dracœnosaurus, an animal nearly related to the dragon in its dentition, and one or two frogs.

Fishes likewise exist, but the fragments have as yet been imperfectly studied.-Professor Pictet, Bib. Univer. de Geneve, 15th September 1846.

On the Volcanoes of the Moon. By JAMES D. DANA. Extracted from the American Journal of Science, vol. ii., Second Series.*

The surface of the moon affords a most interesting subject for the study of the geologist. Though at a distance of many thousand miles, the telescope exhibits to us its structure with wonderful distinctness; and already, as a learned astronomer has observed, we are better acquainted with the actual heights of its mountains, than with those of our own planet. Having an atmosphere of extreme rarity‡ (if any)

*Read before the Association of American Geologists and Naturalists, Sept. 1816.

† M. Arago, Annuaire des Longitudes, pour l'an 1842, 2d ed., Paris, 1842.— P. 526, in an article on the Lunar Volcanoes, Arago says :-" Il est remarquable que grace au zèle et à l'exactitude d'Hevelius on ait connu la hauteur des montagnes de la Lune beaucoup plus tôt que la hauteur des montagnes de la Terre."

The evidence in favour of the existence of an atmosphere and of water in The moon, hitherto obtained, has not been deemed satisfactory. Herschel, at an