Among the other families of gasteropodes, I do not remember any that are exclusively carnivorous, except the genus Testacéllus, to outward appearance scarcely differing from the common slug, but distinguished by carrying a small shell above the tail, and a species of Vitrina, or shelled terrestrial snail, found under stones in moist, shady, or grassy situations in the higher parts of the Island of Madeira. Unlike the slugs, the Testacéllus burrows in the soil, and is the dread of the earthworm on which it feeds; and these habits are accompanied with corresponding changes in its organisation. Its body is more cylindrical than that of the slug, and, in lieu of a shield confined to a limited portion of the neck, the whole body is encased with a thick coriaceous coat, to guard from the additional pressure to which it is exposed, and to afford sufficient strength to execute its furrows. But the most marked differences are found in the digestive organs. In the mouth there is no corneous denticulated jaw, nor a membranous spinigerous tongue; but from between two vertical lips issues a very small cylindrical proboscis, and appropriated to it a muscle which forms the most curious part in the structure of the creature. It is large, cylindrical, lies along the whole belly, and is attached to the left side of the back by a dozen of very distinct fleshy slips, almost perpendicular to the principal muscle of the body. (Cuvier, lib. cit. Mém. xii. 7.) The size and strength of this muscle indicate its paramount importance; nor do all its actions seem to be ascertained, although one of its uses is certainly to retract the proboscis, and probably at the same time to grasp with firmness the struggling victims of its ferocity.* The carni

Since this letter was written out for the press, a very interesting paper on the Testacéllus has been published in this Magazine. (VII. 224.) From the observations of Mr. Denson, it is proved that the animal has the power of suddenly darting out its tongue to seize its prey: - "It is projected and applied in an instant; and, when applied, the action of a muscular structure, connected with its origin, draws it, and with it the worm, into the slug's mouth." (p. 227.) We now know the use of the remarkable muscle of Cuvier.

G. J.

I have, in p. 226-230., shown, that, after I had made the remarks there published, I had found that equivalent and many additional ones had been published, long before, by M. de Férussac and Mr. G. B. Sowerby. The following one, from Mr. G. B. Sowerby, I strove to present in p. 227., in connection with those there published; but want of space excluded it :— "We have observed them [individuals of T. scùtulum] attentively, and were rather surprised that an animal generally so extremely sluggish in its motions, after discovering its prey by means of its tentacula, thrusting from its large mouth its white, crenulated, revolute tongue, should instantly seize upon, with extraordinary rapidity, and firmly retain, an earthworm of much greater size and apparent force than itself; but which, by its utmost exertion, is unable to escape." (G. B. Sowerby, in his Genera of Recent

vorous Vitrina (Helicolìmax Lamárckii of Férussac) differs from our native species in some respects; but, according to the Rev. Mr. Lowe, to whom we owe our acquaintance with its habits, "is so closely allied, that it would be very rash at present to separate it" from the genus.* When leaves and other vegetable matters were given to it, they were never touched, even although care was taken that the Vitrìna should have nothing else for nearly a fortnight; but, on the very first night of its confinement, it would kill and eat a small snail, and it preyed on its own species greedily, the larger slaying the smaller, and then indulging its cannibal appetite. Two of nearly equal size being put together, the stronger or braver slew his neighbour, which furnished a plentiful repast for two or three succeeding nights, for it is during this season only that they feed. (Lowe, in Zool. Journ., iv. 342.) It would be well to ascertain whether our own Vitrìnæ are not equally carnivorous and addicted to cannibalism: they are at present believed to be herbivorous; but Mr. Jeffreys informs us that V. pellucida " has the same carnivorous propensities as the smaller Limácidæ and Testacélli; and I once," he adds, "detected no less than seven individuals busily engaged in feeding on a scarcely dead earthworm, which was faintly writhing about, and endeavouring in vain to get rid of its assailants." (Linn. Trans., xvi. 506.)

The Pteropodous Mollúsca are probably zoophagous; the minute Crustacea and Medùsæ, or particles of dead animal matter floating in the sea, furnishing their nutriment. Some species of this order abound amazingly in the Arctic Ocean, where the marine vegetation seems too scanty for the requisite supply of food; and, moreover, they are found floating far from the shore, and at the surface, where no vegetables are. We have, however, no certain information on this head.

On the contrary, it is well ascertained that all the Cephalópoda are carnivorous, and for voraciousness and ferocity may justly claim precedence among molluscs. Such of them as swim in the bosom of the ocean, as Lolìgo, feed upon fish

and Fossil Shells.) Mr. J. D. C. Sowerby has, too, shown me, in a specimen preserved in spirits, that the tongue is furnished, around and just beneath (if not upon) its margin, on the outside, with short hair-like bristles, which doubtless increase its power of retaining secure hold. Mr. Sowerby also showed me, in other specimens, that the inner face of the stomach, or of the parts leading into it, is furrowed and roughened, in aid, it may be presumed, of the slug's ingesting its prey.-J. D.

*This opinion of Mr. Lowe's is confirmed by the anatomy of the species, excellently developed by the Rev. M. J. Berkeley in Zool. Jour., No. xix. p. 305.

in general, and they will frequently tear large pieces from those which have swallowed the baited hook, and deprive the fisherman of his gain. I have had more than one specimen of Loligo vulgàris brought me, which, adhering with a fatal tenacity to the fish, had allowed itself to be drawn from the water; and in the stomachs of others I have found not only the undigested remains of this food, but the beaks of small individuals of their own species. The tribes, again (Octopòdeæ and Naútili) (See Mr. Owen's beautiful and perfect Memoir on the Pearly Nautilus, p. 24.), whose habit is to crawl along the bottom, and seek concealment in rocky places, prey principally on the larger Crustacea, which find in their hard spiny shells, and their powerful claws, no protection against these voracious enemies. In the Mediterranean, the Ŏctòpi are held in detestation by the fishermen, because of the havoc they commit among the most esteemed species of lobsters and crabs, which is so extensive that scarcely any are to be found in their usual haunts during the summer season, and what have chanced to escape evince, by their mutilated condition, the peril they have run (Cuvier, lib. cit. Mém. i. 4.) According to the early naturalists, the cuttle entraps its prey, partly, at least, by stratagem: "and albeit otherwise it be a very brutish and senselesse creature, so foolish withall, that it will swim and come to a man's hand; yet it seems after a sort to be witty and wise, keeping of house and maintaining a familie for all that they can take they carry home to their nest. When they have eaten the meat of the fishes, they throw the empty shels out of dores, and lie as it were in ambuscado behind, to watch and catch fishes that swimme thither." (Holland's Pliny, i. 250). Pliny also informs us, on the authority of Trebius Niger, that the Cephalopoda are most desirous and greedie of cockles, muscles, and such like shell fishes ;" and, in order to reach the animal scathless, they "lie in wait to spie when the said cockles, &c., gape wide open, and put in a little stone between the shels, but yet beside the flesh and bodie of the fish, for feare lest, if it touched and felt it, she would cast it forth again: thus they theeve, and without all danger, and in securitie get out the fleshie substance of the meat to devoure it: the poor cockles draw their shels together for to clasp them between (as is above said), but all in vaine, for by reason of a wedge between, they will not meet close, nor come neere together. See how subtle and craftie in this point these creatures be, which otherwise are most sottish and senseless." (Holland's Pliny, i. 251.)

The cuttlefish, I need scarcely remark, are all guiltless of this clever stratagem: their warfare, though cruel, is open,

and they are amply furnished with the necessary weapons. The long flexible arms which encircle the head are set along their inner aspects, with numerous cup-like suckers, which the animal can fix to any object, and the adhesion is strengthened by a horny ring round the edge of each sucker often pointed with sharp curved teeth. (fig. 54. a.) "When

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an animal of this kind approaches any body with its suckers, in order to apply them more intimately, it presents them in a flat or plain state; and when the suckers are thus fixed by the harmony of surfaces, the animal contracts the sphincter, and forms a cavity in the centre, which becomes a vacuum. By this contrivance, the sucker adheres to the surface with a force proportioned to its area, and the weight of the column of air and water, of which it conThe jaws, and a portion of the en- stitutes the base. This force, multiplied by the number of suckers, gives that by which all or a part of the feet adhere to any body. This power of adhesion is such, that it is easier to tear off the feet than to separate them from the substance to which the animal chooses to attach itself." (Cuvier, Comp. Anat., trans., i. 432.) It must, then, be a fearful thing, for any living creature, to come within their compass; for, entangled in the slimy serpentine grasp of eight or ten arms, and held by the pressure of some hundreds of exhausted cups, escape is hopeless, and the struggles of the hapless victim, by bringing its body into more rapid contact with the suckers not yet applied, only accelerate its fate.

larged part of the foot, of Lollgo sagittata.

The digestive system of this tribe is less uniform in structure than, from the sameness of their food, we might at first suppose; but, in sketches of the very general character to which I limit myself, I pass over the peculiarities of tribes, to notice little beyond what is common to the class. The mouth, formed by a puckered fold of the skin, is placed at the base, and in the centre of the circle formed by the arms, and is armed with two powerful corneous jaws, having a vertical motion: they are fashioned to the resemblance of a parrot's bill (fig. 54. b), and are well adapted to tear their prey piecemeal, or crush the hard shell, especially when, as in the Naútili, their tips are hardened and calcareous. Between the jaws lies the tongue, adherent to the platform of the mouth,

VOL. VII.- No. 41.

EE

but capable of being unrolled to a slight extent, and having its surface roughened with many rows of small sharply pointed tricuspidate, or semi-tricuspidate teeth, set in close and regular array, which can be erected at will, so as in some measure to grate down the food, previously to its transmission to the gizzard, and they greatly facilitate its descent by their direction, and by their motion backwards and forwards. In the mouth, the food is mixed with the saliva, which is secreted by one or two pairs of large glands. The gullet is a narrow membranous tube, of nearly uniform calibre throughout in the Lolìgo

(fig. 55, 56. a), and penetrating the substance of the liver before it enters the gizzard; but, in the Octopus, the gullet is only bound to the surface of the liver, and at the point of

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