possess at present, I should, on the contrary, deem it to be very familiar and confiding. This I just cursorily mention as a caution to those who would infer the general character and disposition of a species from observation of an individual. Animals of the same kind often differ greatly in individual character; and this is remarkably apparent in a brood of ten young bottletits which I have this season reared: it was observable even before they had left the nest.

The bramble finch, like many other species, but chiefly those which have deciduous terminal edgings to their winter plumage, as the linnets, redstarts, stonechat, pied flycatcher, and some of the siskins and grosbeaks, is very much handsomer when two years old than when in its first summer livery. The tints of all these birds are considerably brighter after they have moulted twice, and then (as is particularly observable in the common redstart) a few only of the new feathers are fringed with winter edgings.

I cannot exactly reconcile the mountain linnet, or twite, which, in these parts, is a regular winter visitant, with Mr. Selby's description of it. That gentleman remarks that "it is rather larger than the common linnet, being bulkier in the body, and having a longer tail." Now, all the twites which I have seen (and they amount to many dozens) have invariably been considerably smaller than the common linnet, being intermediate in size between that bird and the redpole. Farther, Mr. Selby's account of it seems to imply that it exhibits a marked seasonal change in the tints of its plumage; "rendering its summer appearance different from that which it bears through the rest of the year." I have specimens in summer plumage; and the only difference I can perceive is an increased brightness of colour on the rump plumage, the terminal edgings of which have disappeared; but this is by no means conspicuous, being a much slighter difference than is observable in the common linnet and the redpole. In other respects, Mr. Selby's description of the mountain linnet entirely agrees with my birds; only that I see no sexual difference in the colour of the upper parts, the rump excepted. Montagu describes the twite to be "rather larger than the linnet; and says, also, "the top of the head and rump red." But here he is certainly mistaken as regards the head; for I can say decidedly that the twite (of these parts) has at no time any red upon the crown. These discrepancies almost lead one to suspect that two different species are yet confused together under the name of mountain linnet; as, I am quite convinced, is the case with the redpole. See the Field Naturalist's Magazine for April, 1834, p. 172.

Tooting, Surrey, May 29. 1834.

ART. V. Illustrations in British Zoology. By GEORGE JOHNSTON, M.D., Fellow of the Royal College of Surgeons of Edinburgh.

22. Teʼrgipes PU'LCHER. (fig. 59.)

Cl. Gasterópoda, Ord. Nudibránchia, Fam. Glaúcidæ.

THE Térgipes is a naked sea snail with external branchia disposed in two series, one along each side of the back; they

are of a cylindrical form, and it is supposed that the apex of each forms a little sucker by of which the animal can fix itself to the stalks and fronds of sea

means

ations to assure us of its certainty; and the species about to be described never performed any such remarkable feat during the few hours it was preserved.

One species (Dòris maculàta Montagu) has already been described as a native of the coast of Devon, but it differs in so many particulars from ours, that some may deem it necessary to arrange them in separate genera, and we, at all events, may be spared the necessity of elaborating a comparative description to prove their distinctness. Térgipes púlcher was found in Berwick Bay, upon a piece of wood brought up by the line from deep water: its motions were slow and gliding, like the rest of its tribe; but, unlike the greater number of these, it was ornamented with spots of such warm and brilliant colours, that it might possibly have attracted the notice of even those who wonder very much what there is in a snail that it should have admirers.

Térgipes púlcher is half an inch long, ovate, soft, white, ornamented with scarlet tubercles scattered over the back, and with short cylindrical processes tipt with bright orange arranged round the sides: mouth subinferior, terminal, with a linear-oblong membranous tongue, set with minute prickles in close transverse series: tentacula two, dorsal, non-retractile, short, oval, imbricate, orange-coloured: back even, studded with many scarlet unequal tubercles, some of which, when

magnified, appear ocellated: towards the tail are three short white processes placed in a line across the back, which are not retractile; and there are eighteen short obtuse branchial processes placed on the margins, the smallest in front, and all tipped with orange; the apices, perhaps, conformed like suckers: foot oblong, with plain margins: aperture of generation lateral and anterior.

When viewed through a magnifier, this pretty mollusc has a roughish or flocculent appearance. The cloak contains numerous calcareous spicula interlaced in every direction, the spicula of unequal sizes, curved, with a sort of knob in the centre, whence it tapers to each end, the points of some of them being forked. The latter sort are abundant in the branchial processes, and the forked end is always pointed outwards.

The specific character may be thus expressed:

Térgipes pulcher. Corpore ovato, albo, supra tuberculis coccineis notato; tentaculis duobus, ovatis, imbricatis, aurantiis; branchiis brevibus, apice aurantiis.

23. ? SPO'NGIA SUBE`RIA. (fig. 60.)

OUR figures of this remarkable production are taken from a dried specimen, with the loan of which I was favoured by Mr. Bean of Scarborough. It incrusts a univalve shell,

60

Spongia subèria, of the natural size.

apparently the Túrbo crassior, and entirely covers it. The zoophytical crust is thin and uniform, and no pores or fæcal orifices are visible on the surface, but the processes are hollow, and their walls, which are smooth and alike on both surfaces, appear to be perforated, in a longitudinal direction, with a circle of small canals which probably open on the rim of the process; but this structure is rather inferred from the appearance presented by the spot from which a process has been broken, and from an obscure vestige of pores on the rim, than from dissection, and remains, therefore, open to correction.

The sponge is apparently composed of fine particles of sand closely compacted, and is of a uniform grey or stone colour; the surface is even and smooth, but large papillary processes, from one to six lines in height, cylindrical and tubular, rise up irregularly from it, the apices of which are circular, cupped,

with a thick somewhat inflected and plaited rim. Where the sponge incrusts the shell it is thin, but the tubular processes are between two and three lines in diameter, and, when removed at the base, they leave a mark exhibiting a circle of cells radiating to the outer edge.

I am of opinion that this is the Spóngia subèria of Montagu (Wern. Mem., i. 100.), in a perfect state. Montagu seems to have met with specimens only previous to their production of the tubular processes, and, if we subtract these from our description, it will be found to correspond in other respects with the description of this excellent observer. He says that the "sponge is of a corky nature, resembling the close texture of the stalk of some species of Bolètus. It has rarely any other pores than what are formed by the fibres, which are so extremely fine, as not to be visible to the naked eye, even when broken; and with the assistance of a pocket lens, they are not definable on the surface. Its colour is orange-yellow when fresh, becoming brown when dry its shape is indefinite, but it has the singular property of being attached only (as far as I have been able to ascertain) to old univalve shells, which it entirely invests. It is also remarkable, that few instances occur where the hermit crab has not formed a lodgement in the nucleus shell, and there appears to be a great struggle between the two parasitical intruders, as the sponge is continually endeavouring to fill up the aperture of the shell, while the crab, by its occasional motion in search of prey, frustrates that natural propensity of the sponge. Notwithstanding the efforts of so active and restless an intruder, the gradual and insensible increase of the sponge gains upon the premises of the crab; it pushes it on all sides, and completely lines the interior surface of the shell, so that the crab soon finds its habitation too small, and is compelled to search for a more capacious house."

Dr. Fleming has placed this sponge in his genus Halichondra (Brit. Anim., p. 522.), distinguished from the other genera of the family by the siliceous spicula which enter so abundantly into its organisation; and he says that the spicula of the species in question, which he has found" incrusting corallines in the Frith of Forth," are fusiform and slightly curved. Montagu makes no mention of these spicula, which probably require a high power of the microscope for their detection, and hence they also escaped my observation. To any correspondent of this Magazine I should feel much indebted by the communication of specimens of the Spongia subèria, either dried or preserved in spirits.

Berwick upon Tweed, June 12. 1834.

ART. VI. Fùsus Turtòni Bean, and Limnèa lineàta Bean, Two rare and hitherto undescribed Species of Shells, described and illustrated. By WILLIAM BEAN, Esq.

Fu'sus Turtòni Bean. (fig. 61.)-Shell fusiform, covered with slightly elevated spiral lines broader than the intervening

spaces, and crossed by numerous longitudinal lines of growth. Length 4 in., and about 2 in. broad; volutions 9, a little raised in the middle, from which they gradually slope to the separating line; aperture ovate, nearly of the same length as the spire; canal wide and short; outer lip a little dilated and very thick; inner lip smooth, glossy, and much spread on the pillar. Colour white, covered with a brown epidermis, and the inside pale violet.

This noble and probably unique shell we have named after our old and esteemed friend, Dr. Turton. It was found among the rejectamenta of a boat at Scarborough, and is one of the "great guns" of our collection, which contains (we say it proudly) 1050 species and varieties, and above 50,000 specimens of genuine native shells. Limnèa lineata Bean. (fig. 62.)-Shell oblong-ovate, subventricose, with about 12 long and short (often forked)

a

62

a, Limnèa lineàta; b, reversed variety.

raised transverse lines on the body whorl, giving it an angular appearance crossed by numerous longitudinal striæ. Length of the largest specimens 6 lines, breadth 4