Mr. P.'s account of the Encrinites and Pentacrinites evinces his familiar acquaintance with those singular relics; and it is followed by a systematic reference to Miller's Natural History of the Crinoidea.

The arrangements of the Echinodermata by Woodward, Klein, Phelsum, Leske, and Lamarck, are shortly reviewed, and that of the last-mentioned naturalist is adopted, with a few modifications. None of their remains appear to have been detected in the transition or mountain lime-stone: but they have been traced in the lias, in the fuller's earth of the inferior oolite, in the beds of the upper oolitic series, and abundantly in the green sand and chalk. The recent and fossil-kinds form a voluminous category.

In treating of shells, Mr. Parkinson chiefly follows the nomenclature and divisions of Lamarck, occasionally adverts to the somewhat hasty conclusions and the unnecessarily minute distinctions of De Montfort, and subjoins a table of the genera and species of British fossil-shells, in the order of the strata in which they have been found to occur; with a list of fossils belonging to the mountain and transition lime-stones of Cork, communicated by Mr. Miller, author of the Crinoidea. reflections which accompany these expositions are fairly deducible from the premises, and, together with other particulars to which we have already alluded, will satisfy our readers that the present introduction is by no means a mere compilation, but bears the impress of an original treatise. We may cite an example, in the observations on Mr. Miller's list:

The

It has been conjectured by some naturalists who had become convinced of the comparatively late creation of land-animals and of man, that the peopling of this planet had commenced, in the enduing with the principles of life beings of the simplest forms and organization; and that, by the influence of certain external causes, acting through passing ages, those changes had been gradually wrought in succeeding animals, from which have resulted the numerous differences which constitute the various tribes rising from the almost lifeless sponge to the highly complex and more perfect animal, man. On this hypothesis it might have been expected that those beings which had possessed life under its most simple modifications, would be found in the earliest formed strata; and that, in proportion to the lateness of the period at which the strata were formed, would be the degree of complexity in the organization of the inhabitants whose remains they would contain. But investigation has ascertained, and the preceding table manifests most decidedly, at least, with respect to the class of animals of which we are now treating, that such a conjecture is ill founded. In the carboniferous and the mountain limestone are the remains of shells of the earliest creation, which are

unexpectedly found, with hardly an exception, to exceed, in complexity of structure, all the shells which have been discovered, either in any subsequent formation, or living in our present seas. It is in this early creation that those shells are found which possess that complicated structure, very rarely found in the shells of this day, which enabled their inhabitants to rise and sink with them in the water. Such are the many-chambered univalves, the Nautilus, Ammonites, Orthoceratites, &c. The bivalves and multivalves of that era also seem to have been endued with a similar property.'

The existence of alleged Helices in the mountain lime-stone, and in other early deposites, scarcely militates against this train of reasoning; for it is still doubtful whether the shells in question belonged to the snail-tribe, or to certain testaceous animals which possessed the faculty of rising and sinking in the water. Again;

The geological enquirer will derive some assistance from the examination of fossil-shells, whilst endeavouring to ascertain how far the earth contained in the testaceous and crustaceous coverings of marine animals has contributed to the formation of calcareous rocks. It has been conjectured, that besides adding to the bulk of the limestone or chalk by the accumulation of their remains still bearing their original forms, that they have also contributed to the surrounding matrix by a solution and subsequent precipitation of the lime which had entered into their composition. If this had been the case, we might expect to find those remains which still bear their original forms, manifesting every degree of resolution, from the slightest influence of the agent in destroying the finest striæ to the smoothing of ridges, and even the diminution or removal of projecting points. But nothing of this is discoverable in the fossils of either the flint, the limestone, or the chalk. In the latter, which, by the fineness and purity of its substance, gives strong evidence of its having been deposited by precipitation, not the slightest appearance of chemical action on its contained fossil-shells is observable. If preserved at all, they are preserved with their sharpest ridges and minutest points in the most perfect state.'

Among the remnants of fossil-insects involved in amber, the author might have enumerated various species of ephemerous and crane flies, phryganea, ants, caterpillars, and a few of the coleopterous class; which, with others, are figured in Sendelius's Historia Succinorum. In the same substance, some of the French naturalists have discovered platypi, mole-crickets, small termites, a minute mantis, and a species of atractocerus. The Indusia tubulata of Bosc, which seems to be analogous to the case of the cadero worm, occurs abundantly in the secondary fresh-water formations. An exotic insect described by Faujas, who

who discovered it in a schistose marl in the department of the Ardèche, has been referred by Latreille to the genus Polistes of Fabricius.

Properly authenticated instances of the fossil-vestiges of birds are far from numerous. Previously to the investigations of Cuvier, not more than five cases had been distinctly recognized: but that illustrious comparative anatomist has added seven to the list. More recently, a few bones belonging to animals of that class have been found in the Kirkdale cavern, in Yorkshire one, in particular, figured in the Geological Survey of Yorkshire, is supposed to be the wing-bone of a goose, or large duck; and Professor Buckland obtained from the same repository the wing-bones of a raven, and of a large pigeon, distinctly characterized. The only well-attested example of petrified eggs is, we believe, that of six which have been ascribed to the partridge, and which were found in a crystallized state in disrupted soil, at Terruel, in Aragon, by workmen employed to dig for the foundation of a bridge. These curious specimens are described by De la Metherie, in the fifty-third volume of the Journal de Physique; and the nature of the territory in which they were found is particularized in the same volume, by Proust.

Mineral repositories of fishes are more frequent: but the mutilated or distorted state of the specimens generally precludes their accurate recognition; so that the determinations even of De Blainville have in several cases proved premature. Mr. Parkinson points to the principal known localities, and to the imperfect results of the observations which have been instituted concerning them. Somewhat more precision attaches to relics of crocodiles and other Saurian animals, in consequence of the anatomical distinctions so diligently laid down by Cuvier, and the synoptical arrangement of the tribe proposed by Mr. Conybeare, both of which aids are adopted by the present writer.

It was with peculiar satisfaction,' says the latter, in a note, that, whilst this part of the work was in the printer's hands, I was favoured by William Rhodes, Esq. with some fossil-bones which had been found in a pit dug in the London clay, at the depth of eighteen feet from the surface, in Hackney Fields. Finding these to be the remains of a crocodile, and being aware that no such remains had hitherto been found in this formation, I immediately repaired to the pit, with the hope of securing the remaining parts of the skeleton; but too late all the other fragments were irrecoverably lost, except a few broken vertebræ. On perceiving the skeleton, which, I was informed, was lying in a curved position, the workmen rushed on it with their pickaxes and shovels, each striving to obtain a portion of the supposed monster, until its demolition was accomplished.

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The pieces which I obtained were two small fragments of the upper, and one of the lower, jaw, with a series of the vertebræ, and two obscure fragments of the leg.

Fortunately, the two pieces of the upper jaw, on being placed together, gave the formation of the snout, from the ninth tooth to its anterior termination, and yielded a complete view of the grooves for the lateral admission of the large fourth tooth on each side of the lower jaw. The teeth were broken off to the margin of their alveoli: but they thus showed, in their transverse section, their cutting ridges, their striated surfaces, and their central cavity, beautifully encrusted with bright pyrites. The fragment of the lower jaw also was of its anterior termination, but of only half the length of the two fragments of the upper jaw, and contained four teeth on the left and two on the right side.

The form of the two conjoined pieces of the upper jaw, gradually tapering anteriorly, but enlarging at the termination, with the lateral grooves for the fourth tooth on each side of the lower jaw, proved decidedly that it was not the jaw of a gavial, or of the same species with the one whose jaw was discovered at Honfleur. The characters possessed by the jaw are those of the recent species, Crocodile a museau aigú.

The fragments of the vertebræ, though slightly mutilated, furnish useful and interesting information. Unlike the vertebræ of the two fossil-species of Honfleur, as described by Cuvier, they have, throughout the whole spinal column, the anterior surface concave, and the posterior convex, and so strongly so, as fully to equal, if not exceed, those of the recent species in this respect.

I could procure only twelve vertebræ of these, two were cervical; one, anterior dorsal; seven, posterior dorsal and lumbar; and two, probably anterior caudal; but the marks for the articulation of the chevron-bone were not visible. They corresponded so very nearly with the vertebræ of the recent crocodile in particular, as to require no farther description than that which is given by Cuvier of these; his figures would also equally serve to represent them, for they differ only in having the extremities of their spinous and transverse processes generally broken off.

every

Of the uncertain fragments, one bears somewhat of the curved outline of the humerus, but, of the other, no opinion can be safely proposed.

It does not appear, from what is at present known respecting this fossil-animal, that it specifically differs from the recent crocodile.'

The most important points of distinction between the conformation of the skeletons of Ichthyosaurus and Plesiosaurus, and that of crocodiles and lizards, are well elucidated in the notes.

In his cursory statements with respect to the petrified remains of quadrupeds, Mr. Parkinson alludes to one or two more species of elephant than those that have been indicated

by

by Cuvier, grounding his discriminations on the structure of teeth in his own possession. Mr. Campbell's alleged unicorn appears, from his own description, to be the common twohorned rhinoceros of Africa, and to differ from the fossilspecies by wanting the space between the horns.

From a retrospect of his subject, the author has been led to infer successive acts of creation and changes in the state of our planet, at remote intervals, corresponding with the appearances which he has recorded; and he insinuates that the days of création, commemorated in the Mosaic account, may have been periods of long and indefinite duration. If so, how are we to interpret Scripture? or, are we to mould the import of the text according to our preconceived physical theories? Our geological conceptions certainly seem to countenance the notion that man was the last being who was called into existence on the face of the globe; while his very tardy appearance, to possess superior intelligence and enjoyment, is not easily reconcilable with the attribute of benevolence which we cannot fail to ascribe to the Deity. Consigning, therefore, these mysterious themes to the meditations of the metaphysician, or rather to intelligences of a far higher order than ourselves, we take leave of Mr. Parkinson, with our best thanks for his comprehensive exposition of interesting facts; and with a friendly hint that he should not disdain a little attention to correct printing and grammatical phraseology.

ART. IV.

Memoir of John Aikin, M. D., by Lucy Aikin: with a Selection of his Miscellaneous Pieces, Biographical, Moral, and Critical. With a Portrait. 8vo. 2 Vols. 1l. 4s. Boards. Baldwin and Co. 1823.

FEW

Ew men who have not attained to splendid eminence have been more before the public than the late Dr. Aikin, and no man has sustained a more uniformly respectable character both as an individual and as a writer. He has indeed long filled a great place in the all-encircling amphitheatre of British literary enterprize; and his extensive contributions to the "Universal Biography," an important work which was planned, superintended, and in a great degree executed by himself, would alone attest his industry, his acquirements, and his equity. Yet he found leisure to compose also excellent books of education, which are reprinted almost annually; to produce several statistical, political, and historical works of high merit; and also to adorn the elegant literature of the language with many tasteful critical disquisitions. His poems, if few, are polished, were readily devoted to the social

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