spires turn in the more unusual manner, has (to our knowledge) ever been met with to vary from that formation; as such accidental defor mities have been found in a few instances, amongst those which are usually termed dextrals, or have the more usual spiral turns, and have become lusus heterostrophon shells.

In order therefore to explain, which way the turn of the spiral convolutions of a reversed shell takes, omitting the vague signification of turning to the right or left; we shall observe that the more com mon turn of shells is with the apparent motion of the sun, or as the index or hand of a clock moves.

But in order to be more clearly understood, let us compare the spiral volutions of a shell to a common cork screw, and we shall find, that whether the mouth or apex, is placed upwards, the spires will turn from the upper to the lower end like a common screw, which is in the same direction as the index of a time-piece, and what is commonly understood by a dextral or right-handed screw. As a further definition, such shells have their aperture on the right side, when examined with that end downward, and is in the direction of the sun's apparent motion.

On the contrary, a reversed shell, when placed in a perpendicular position, has its spiral volutions in an opposite direction to the motion of the index of a watch, or a clock, or to a common screw; and in fact resembles what is usually termed a sinistral, or lefthanded screw. These have their aperture on the left side, or opposite the left hand of the person holding the shell with the mouth downward; and the opening is opposite the sun's apparent motion.

In order to determine whether a flat shell, whose volutions are laterally placed, is a reversed species, we have only to examine which way the volutions turn from the apex or centre towards the mouth; and if we find it contrary to the motion of the index of a watch, it is a heterostrophe, or reversed shell: and vice versa,

In some of the more depressed species of Helix, or Nautilus, attention is requisite to be paid to the mouth, in order to determine which is really the upper side of the shell, for it is on that side the spiral turns are to be taken from the centre or apex and in most instances this is to be determined by the oblique direction of the aperture to the under part, where the lip rarely extends so far as on the upper part. In fixed shells, such as Serpula, there is no difficulty, as the side which is sessile must be considered as the base, or under part. Thus in the Serpula lucida the fixed part is sometimes very small, and the mouth protends spirally upwards in a contrary direction to the sun; and therefore must be considered a reversed or heterostrophe shell, the same as if the volutions nearest the mouth had turned laterally upon the centre or fixed ones.

This shell, indeed, is most frequently found with regular lateral volutions; and though subject to great variety with respect to contortions, it invariably turns the aperture one way.

In some species of Nautilus, however, there can be no rule to ascer tain whether it is dextral or sinistral; for when the aperture is exactly lateral, the lip collapses the body equally, and the sides of the shell similar, as in N. Calcar, it cannot be defined.

In others of that genus, as in N. Beccarii and Beccarii perversus, two shells, the principal distinction of which is the contrary turn of their volutions, it is easily determined, by the convexity of the upper side; and of course the aperture being placed somewhat beneath."

Helix, which likewise presents us with various additions and much diligence of criticism, comprehends sixty-eight species, classed under the general designations of ovate, sub-globose, and depressed.-Lacuna, one of the non-descripts, is not limited to the habitations noticed by the author. We have seen several specimens (some nearly half an inch in length) from Tiree, a remote island of the Hebrides.-With respect to the amours of H. aspersa, we have these observations:

So much has been already written by different authors on the loves of Snails, which requires more than common faith to credit, that we must beg to refer our curious readers to the more recent accounts of the actions of Snails in love, given in the first volume of the Naturalist's Miscellany; where the author very properly prepares the reader for the belief of such wonders, by saying, "I must request my readers to summon all their philosophical faith to receive the surprising particulars."

That the hermaphroditical animal of the Helix aspersa, as well as H. nemoralis, (or at least some of them,) possess small testaceous spiculi at certain seasons, must be admitted; but that they are missile darts, we have much reason to doubt, though it is natural to suppose the animals are furnished with them, for the purpose of stimulating each other to love, because it is only at that season they are found to possess them. If such are ever discharged at each other, we have been extremely unfortunate in our observations, for in no one instance, could we ever find the dart penetrated; though at the time the ani-, mals are close, the point may irritate: but it is neither sufficiently strong, nor sharp pointed, to penetrate the tough skin with which these animals are furnished; and, indeed the extremely viscid secretion, with which they are so copiously provided, adheres so strongly to these spiculi, when wholly projected from the body, that they are for a time held by it. Perhaps we may be told hereafter, that this tough excretory fluid is used as a cord to regain these darts after they have been discharged: but such we should hold equally fabulous, with much of the accounts related by various authors.

These celebrated love-darts are sub pellucid-white, and very brittle, about a quarter of an inch, or three eighths in length, and somewhat triangular, like the blade of a small sword.'

Nerita and Haliotis have received no additions. Of thirteen species of Patella, the bimaculata occurs for the first time. One of this rare sort was found at Falmouth, and another near Milton, on the south coast of Devon.

Dentalium has supplied three non-descripts, namely, gadus, trachea, and glabrum.

The

The Linnéan Serpule are divided into such as adhere to other bodies, and such as are free and detached; the latter constituting a new genus under the title of vermiculum. Among fifteen of the former kind, we have to notice, as non-descripts, carinata, corrugata, heterostropha, minuta, reversa, and tubularia. Nothing,' says Mr. Montagu, has puzzled the conchologist more than the four species of Linnæan Serpule under the denomination of Vermicularis, intricata, triquetra, and contortuplicata.' He also remarks: We have collected a vast quantity of these Serpule, single and grooped, angulated and cylindric, with all the intermediate gradations, which connect them so nearly, that were it not for the animals, we should have been induced, to have considered them as one and the same species: we have, however, by the animals, more than by the shells, formed them into two species; namely, vermicularis and triquetra.'

The descriptions of most of the Vermicula are still imperfect. Sixteen are particularized; and oblongum, perlucidum, urna, and squamosum, for the first time.

As the article Teredo navalis must be interesting to many besides naturalists, we offer no apology for the subsequent ex

tract:

It has been erroneously imagined, that the animal perforates wood by means of its anterior valves; but there is no reason for ascribing such a property, because, their shape has been likened to an auger, when we find all the Phalas, the Mytilus rugosus, the Donax Irus, and many others perforate not only wood, but even the hardest lime-stone, without the assistance of their shells, a part impossible to effect it.

It is observable the Teredo bores across the grain of the wood as seldom as possible; for after it has penetrated a little way, it turns, and continues with the graiu, tolerably strait, until it meets with another shell, or perhaps a knot, which produces a flexure: its course then depends on the nature of the obstruction; if considerable, it makes a short turn back in form of a syphon, rather than continue any distance acros the grain.

We had an opportunity of examining a great number of these shells in the Dock Yard of Plymouth; where every means have been tried to prevent the destructive quality of these pernicious animals, which are now become naturalized to the climate, and have increased considerably, though supposed to be of oriental origin.

The piles we examined had been recently taken up to be replaced with new; these, we were informed, had not been under water above four or five years, and though perfectly sound and solid oak, were greatly perforated *.

. It

* The method now adopted to preserve the timbers necessarily used about the docks, is to cover that part which is continually under

water,

It must be presumed, that the tube is lengthened as the animal's growth requires; and that it can extend the whole length of the perforation without quitting the tail; but that it cannot recede far, by reason of the increase of the anterior valves affixed to the head, and the taper shape of the tube. This part is rarely above threequarters of an inch in diameter at the larger end, and a foot in length, in our climate; but exceeds that in the more southern parts, from whence it was brought into our harbours to the destruction of our ships, as Linnæus justly observes, calamitas navium.'

In compliance with the practice of his predecessors, rather than from his own conviction, Mr. Montagu has admitted Sabella into his arrangement, and has allotted to it the last place. Besides the cirrata, which corresponds to Terebella cirrata of Gmelin, he has introduced to our acquaintance the arenaria, subcylindrica, setiformis, curta, and compressa.

We now hasten to close this rapid sketch of the contents and character of the Testacea Britannica, with a few general remarks.

Though the work comprizes thirty-six genera, and nearly four hundred and seventy species, we are not without our suspicions that, in some instances, the latter have been needlessly multiplied; and that the systematic nomenclature has been occasionally tortured without an adequate cause. The author's personal observation appears to have been too much limited to the south of England; and many gleanings are yet left for the conchologist who shall make the circuit of our shores. To give additional popularity and interest to a performance like the present, we should have recommended compression of many of the characteristic descriptions, a reduction in the size of the paper and type, and more frequent notices of the living. contents of several of the species of shells. In regard to the composition, it is, on the whole, less fruity than that of the Ornithological Dictionary: yet several of the sentences betray a singular contempt of neatness, and are encumbered by such epithets as testaceological, quadrifurcated, perlaceous, and depauperated. Errors of the press, and trespasses against the concord of noun and verb, are also not infrequent :-but, while we advert to these minor delinquencies, we are by no means blind to the genuine and important merits of the publication.

water, with short, broad-headed nails, which in salt water, soon cover every part with a strong coating of rust, impenetrable to these animals and we are assured this has been found to succeed better than sheathing with copper.'

ART.

Muir.

ART. X. Theological Institutes, in Three Parts. By George Hill, D.D. F.R.S.E. Principal of St. Mary's College, &c. &c. 8vo. PP. 444. 6s. Boards. Edinburgh, Bell and Co. London. Longman and Co.

Τ THI 'HE first division of this work presents heads of lectures in divinity; the second, a view of the constitution of the church of Scotland; the third, counsels respecting the pas toral office. The whole affords a spacious field for critical disputation; and, were it possible, for friendly discussion: but alas! such seems to be the state of human nature, or the irritable spirit of Christians, that this desirable conduct is not attainable !It appears to be one purpose of the volume to prove that Calvinism is the doctrine of both the British churches.

Part I. consists of five books under these titles:-Evidences of the Christian religion;--General view of the Scripture system;-Opinions concerning the Son, the Spirit, and the minner of their being united with the Father;-Opinions concern ing the nature, the extent, and the application of the remedy brought by the gospel ;-Index of particular questions, arising out of opinions concerning the gospel remedy, and of many of the particular terms in theology.'-It may be concluded that only a brief and contracted view can be taken of these subjects in the course of 134 pages; yet, though merely a syllabus, the propositions and hints here advanced will doubtless prove useful, not solely to the lecturer, but also to awaken thoughts and ideas in the mind of the student or reader, which he may pursue to advantage. How far the author merits praise as a defender of established orthodoxy, we shall not minutely inquire but we observe here, as in other instances respecting the Trinitarian controversy, that the Father is mentioned as Пnyn edinios, (fountain or source of Deity) &c. an expression which seems to indicate subordination in the Son and Spirit, and consequently is incongruous with that equality which is so directly maintained. Without entering farther into the disputable points which here arise in succession, and which are likely to remain still disputable, with whatever confidence any explications may be asserted, we satisfy ourselves with barely adding the brief remarks of the present author in the close of the chapters on predestination, &c;-where, after having informed us that there are in the English church, Doctrinal Calvinists, Universalists, and Arminians,' he proceeds to say;

On this subject, as on the Trinity, it is not proper to state the controverted points to the people: and men of speculation should exercise mutual forbearance; should not form their

opinion