rowed posteriorly, of a reddish or yellowish-brown colour, stained with the contents of the intestine, annulate; the rings thirteen in number, smooth, furnished on each side with a small fascicle of No. XLVI.-Othonia Fabricii.

a. A tuft of Laurentia pinnatifida, with the animal intermixed, natural size. b. Worm removed from the tube, natural size.

c. The same magnified.

d. Head protruded from the tube, with tentacles displayed, as seen through the magnifier.

e. The same more highly magnified.

retractile bristles, which can be pointed either forwards or backwards; the terminal segment semioval, obtuse, marked on each side with a distinct black speck; bristles bent, and somewhat thickened about the middle, whence they taper to a very sharp point; first two segments rather narrower than the following; the anterior with a projectile semioval process on the dorsal aspect, and marked with two round black eyes? placed towards the sides; branchial tentacula one-third the length of the body, straw-colour, unspotted, in two dense tufts originating in the sides of the head, each tuft consisting of three main stalks, which are ciliated with numerous filiform straight filaments, serrulate with very short processes on their inner aspects; mouth between the tufts; intestine straight, nearly equal throughout; the anus terminal; space between the intestine and sides mottled, transparent.

Obs. This, although not hitherto enumerated among our natives, is certainly the most common species of its family on our coast. It lives in a narrow cylindrical tube, about twice its own length, placed in

an erect attitude at the roots of the lesser Fuci. The tube is constructed of fine mud cemented by a glutinous secretion, and lined within by a thin glutinous skin; and if the worm is removed, and left in clean sea-water, it will, after a short interval, be found to have enveloped its body with a similar pellicle. The motions of the tenant in the tube are very lively; it withdraws on the slightest agitation of the water; and after its terror has subsided, it again pushes the feathery tentacula from beyond the aperture, and expands them in a wide circle, keeping them very steadily at rest; but when extracted from the tube, it lies very helpless. The tentacula are then stretched forwards, and generally held so approximated that they form a brush, like a hair pencil, on the head, having however the apices of the filaments always recurved or hooked. Sometimes the two tufts are a little separated even in this state; but from the number and closeness of the filaments, the division of each tuft into three ciliated branches cannot be detected, unless they are lightly compressed between thin plates of glass.

Fam. XVIII. CAMPONTIADÆ.

CAMPONTIENS, M.-Edwards in Lam. Anim. s. Vert. 2de édit. v. 514.

50. CAMPONTIA*.

Campontia, Johnston, Zool. Journ. iii. 235.

Char. Body cylindrical, naked, annulose: mouth with exsertile corneous mandibles: two prolegs on the anal, and two on the first segment.

1. C. eruciformis.

Campontia eruciformis, Johnston in Zool. Journ. iii. 325, and iv. 421; Loud. Mag. Nat. Hist. viii. 179. f. 18. Aud. & M.-Edwards, Litt. de la France, ii. 290, and M.-Edw. in Lam. Anim. s. Vert. 2de édit. v. 575.

Hab. The sea-shore between tide-marks, where it may be found, at all seasons, at the roots of sea-weeds and corallines, in pools left by the recess of the tide.

Desc. Body 4 lines long, cylindrical, of twelve subequal segments (exclusive of the head) of a clear, faint, water-green colour, smooth, and somewhat corneous. Head distinct, brown, subquadrate, sparingly ciliate on the margins. Eyes two, black, remote, not marginal, placed towards the front. Antennæ two, distant, very short,

* From Káμaros, labor, and πóvτos, mare—a sea trouble, probably intended to express the breach it makes in our natural classifications of the Annelides,—just as a" trouble," in the miner's language, breaks through the continuity of his workable seam. Let us, however, remember the axiom of Pallas:-"Nihil Natura imperfectum condidit, quantumvis videri possit anomalum."

inarticulate, setaceous, originating in the front margin. Mouth with a pair of exsertile, corneous, brown, hooked mandibles, which, when in motion, it is seen incessantly to protrude and retract; no proboscis. On the front and ventral margin of the first segment are two short unjointed legs, armed with a circle of retractile claws; and the last segment is furnished, near its termination, with two similar legs : the other segments are footless and naked; but a few hairs terminate the anal segment,

No. XLVII.

which is very slightly lobate. Anus round, Campontia eruciformis. simple, small.

a

This animal lives among Confervæ, in pools left by the tide; and is very common in Berwick Bay. It moves with considerable quickness by means of its mandibles and legs; for the former seem to be as subservient to progressive motion as the latter; and, during its progress, the upper lip is considerably protruded, as shown in No. XLVII. c. Within the first segment we observe a heart-shaped lobated organ, which, although colourless and almost transparent, is undoubtedly the stomach. The very short gullet enters it above; and from its inferior end a small intestine proceeds, which suddenly enlarges at the commencement of the fourth ring, and continues of the same calibre to its termination at the anus. This large intestine is always filled with earthy feculent matter, except that portion of it which traverses the last three segments, and which is usually empty. Two slender thread-like vessels are to be traced winding down the sides in the space between the skin and intestine; these occasionally anastomose by still slenderer transverse branches; but I could not discover any common centre of departure. At the end of the ninth ring there are four filiform, dark-coloured, tubular organs, which seem to originate in the sides of the intestine: they traverse the ninth and a part of the tenth segment, and end apparently with free extremities. These are probably hepatic vessels; and the deficiency of solid feculent matter in the intestine, below their origin, appears to prove their importance and adaptation to the proper assimilation of the food.

a. Natural size. b. Magnified. c. The head, slightly compressed between plates of glass. d. The under side of the anal segment.

When I first described this animal, its close resemblance to some caterpillars was particularly mentioned, and, indeed, suggested the name. That it was actually a larva I was unsuspicious, for I believed it to be an established fact among entomologists that no insect passed its preparatory stages in sea-water. I was however informed, soon after the publication of the genus, that Mr. MacLeay had proved that our worm was the larva, probably, of some dipterous fly; but in what way this conclusion had been arrived at was stated. Mr. Green thinks that he has confirmed its truth (Charles

not

MEADE.

worth's Mag. Nat. Hist. i. 279); but, in truth, his remarks are very irrelevant, and deserve no consideration. Milne-Edwards, on the contrary, adopts our original view :-" Ce singulier animal a été découvert sur les côtes de l'Angleterre, par M. Johnston, et ne serait suivant M. Macleay qu'une larve de quelque insecte diptère, mais ayant eu l'occasion de l'observer à l'état vivant, dans la rade de Toulon, nous ne croyons pas devoir adopter cette opinion, et nous sommes portés à considérer ce genre comme établissant le passage entre les Neréidiens et certains Helminthes."

1. M. mirabilis.

Fam. XIX. ?MEADE.

1. MEA.

Plate XXII.

Desc. Worm slender and filiform, of the thickness of common twine, and about 4 inches long, soft, distinctly annulated, of a wood-brown colour, with dark specks in clusters along the sides. Head distinct, serpent-like, flattened above, obtusely pointed, scooped underneath; the mouth inferior, about a line from the apex, furnished with a thick, short, subglobular, smooth proboscis. On each side of the mouth at its base, and external to it, there originates a long filiform tentacular appendage, which is fully as long as a third of the total length of the body: they are jointed at not very regular intervals, and naked at the root, but, at a little distance upwards, they begin to be fringed, on one side, with short cylindric obtuse fleshy cirri, in two close-set series, which extend to the very apex. of the filaments is minutely crenulated on the opposite edge, and it is. The rachis furnished with numerous dark minute granules, collected, principally, at the origins of the cirri. Thorax of nine segments, of which eight are equal and similar, about twice as long as their diameter, cylindrical, and distinguished by having a vesicular lobe at the base of the bristles, which are collected into fan-shaped fascicles projecting forwards. The bristles in each fascicle are numerous, unequal, simple, setaceous, flexuous, with a long sharp point, smooth. The ninth segment is thoracic, but it is smaller than its antecedents, with larger lobes at the base of the bristles. Abdomen elongated, cylindrical, the segments twice as long as their diameter, each furnished on the sides with a roundish cluster of dark hard granules, and with four fascicles of retractile bristles placed equidistantly. The bristles are simple, smooth, of a straw-yellow colour, rather stout and furcate, being also bent considerably towards the apex. about eight in each fascicle, and they are shorter and stouter than There are those of the thoracic feet; nor have they the lobe at the base, or only in a minor form.

This singular worm was given to me by Dr. Greville, who does not remember the locality in which it was found. He got it, he

believes, while digging with the trowel for littoral mollusca; and we may conclude, from its structure, that it is arenicolous, probably the tenant of a thin and fragile tube. How it disposes its oral filaments, when in its natural condition, it is hard to say. That they are branchial scarcely admits of a doubt, notwithstanding their anomalous position. When highly magnified, the rachis is seen to be permeated by a comparatively large canal running from the base to the summit, undoubtedly an aquiferous canal; and every cirrus of the myriad that fringe and adorn the upper aspect is a cylindrical obtuse organ, containing a sort of dark grumous or granular texture within a thick transparent coat or skin,-a texture produced by decay and steeping in spirits, but very like the branchial texture in other genera of the class.

It is difficult to assign a place to this worm in our present classifications. The head leads us to compare it with some Nemertina, for example with Ophiocephalus; and yet there is no relationship there. With the Terricoles there is much accordance in the general habit, and in the structure of the abdominal portion, more especially in the feet of the bristles being in four fascicles; and there are Naides in which the head is distinctly marked as in this new genus, and in which there are two kinds of bristles. Yet it is doubtful whether the resemblance is not merely analogical. To refer the worm to the Ariciada is a kind of compulsory connexion, for that family is becoming a refuge of unclaimed foundlings. All the Ariciada known have the branchiæ placed dorsad on the feet, and intimately combined with them; but in this worm they are cephalous, and are far removed from the feet, which are only developed in a small degree. Then for the Tubicole there are even less claims. The distinct head without appendages, the want of hooklets on the segments, the quadriserial fascicles of bristles, and the position of the mouth, are all proofs against any true relationship. It may, however, be noticed here, that were the branchia of Pectinaria to be drawn out into a line, we should have an organ something like to the branchial filament of ? In these doubts, there really seems no alternative but to make this genus the representative of a distinct family.

*These may be represented by the hard granules, but the latter have no regular position nor form.