Part 26

GRANULATE BRITTLE-STAR. SUN-STAR. ]

SUN-STAR.

The general colour of the disk is a fine rose-pink, deeper on a circular area in the centre; the network is a deeper rose, especially just around the bases of the knobs. The base of each ray is crossed by a broad band of pure white, both knobs and network. The remainder of the rays is of a pale orange-scarlet, becoming more truly scarlet in the middle portion; the network of the same hue, but deeper. Over the entire surface the areas of the net are occupied by series of ovate whitish hollows, from each of which protrudes a minute clear bladder or closed tube, exactly like those we lately saw in the little Starlet. The madreporic plate is seen about midway between the centre and one of the angles, as a tiny cake-shaped white body, grooved exactly like a brain-stone.

Beneath, the rays are ploughed with a deep groove, in which are two rows of sucker-feet; towards the tip, however, their place is supplied by long slender pointed tentacular processes. The avenues are bordered by flat knobs, set like the edging-stones of a garden walk, each of which carries five or six spines radiating like a fan, lengthwise. Each set sends off a branch which carries another fan placed transversely, of six to ten spines. Then the white satiny skin sends up at the very edge of the ray short stems, each bearing a group of fifteen to twenty spines, having a tendency to a transverse arrangement, but not in a single row. These form the edges of the rays, seen from above and below. At the bases of the rays beneath, the angle terminates in a broad plate, which is cut into a comb of about eighteen flat spines, the whole having a semi-oval outline, projecting towards the mouth. At the tip of each avenue we discern the little scarlet eye, well protected by the crowding rows of fans.

The mouth gapes, and gives an unexpected insight into the diet of this gaily-painted gentleman. We see a bit of an Echinus shell, and on taking hold of it with a pair of pliers, and carefully dragging, lo! forth comes the entire box of a Purple-tipped Urchin, nearly an inch in diameter, empty of course, through the force of Mr. Sun’s gastric juice, and denuded of spines. Ugh! the cannibal! to eat his own first cousin!

We put him into a shallow pan of water, where he crawls slowly. He is fond of curling the rays over his back, so as nearly to meet, perhaps to have a look at the new world in which he finds himself. Then he turns himself right over in the shallow water, bathing the under surface in the air, the suckers moving all the time to and fro with great rapidity, and (we fancy) with enjoyment.

Several specimens of the common Cross-fish occur, large and richly coloured, and many of the Urchin just named; but these we can find every day in-shore; so they are contemptuously thrown over the gunwale.

GRANULATE BRITTLE-STAR.

Ha! here is a fine thing! It is the Granulate Brittle-star, a species said to be widely spread, but I never saw it before. It is confined to deep water. It is a very fine imposing species, reminding me (a strange comparison, you will say!) of the great South American hairy Spiders, with a brown body and long bristly legs sprawling over a width of eight or ten inches. Its hues are said to be various, but I will describe this as I see it.

The disk is a plump cushion slightly depressed in the centre, of a light reddish umber, or sand-brown. The base of each ray is rich red-brown, the colour encroaching on the disk with two points, and running down the medial line of the ray. This hue is bordered by velvety black, blending with it; and beyond the middle of the ray, the deepening brown is pretty well lost in the black. The ray is edged with spines standing out at right angles, and set in rows. These spines are black with grey points, and greatly augment the noble aspect of the creature. Each ray is about four and a half inches long, running off to a fine point.

The animal resents being turned over, and refuses to lie in a supine position, unlike the “malus pastor” of the poet. It curls and twists the slender ray-tips, crawls rapidly, and courses round and round the edge of the pan into which we have dropped it.

Let me anticipate here to narrate the after history of my captive. Consigned to a shallow tank at home, after a few days I missed him one morning, and on searching the whole room carefully, found him at length under the edge of the hearth-rug, some yards from the tank, with all his rays broken into many pieces, and only the short stumps remaining. Though dry and apparently dead, I perceived a slight movement in the stumps, which gave me hope of revival, and I replaced the poor maimed thing, sadly shorn of his glory, in the tank. He did revive; and the truncated ends of the ray-stumps enabled me to see the arrangement of the spines. These form about nine rows on each side, radiating fan-like; within the undermost row on each side is a row of flexible bladdery tubes much like the suckers, and like them protruding from orifices in the calcareous skeleton, but not retractile. They are studded with tiny warts, and terminate not in a sucking disk, but in a sort of bifid extremity. They are not used for locomotion, nor are they ordinarily applied to the ground as if tactile, and yet are continually thrown round so that the tip is brought up to the base, and this suddenly and abruptly, and every few seconds, as if something were captured and conveyed to the mouth; but this cannot be, for the mouth is not there, and nothing is seen to be seized. Perhaps some intelligence, in a way unimaginable by us, is thus obtained, of outward things.

The poor maimed creature managed to stump awkwardly about for a few days, but soon died, with no perceptible attempt to renew the self-amputated members.

The Brittle-stars appear to move by means of the flexibility of their long snake-like rays, the spines with which they are furnished enabling these organs to obtain a hold on the surface along which they crawl; and that so secure that even perpendicular and very smooth surfaces present no hindrance to their progression. They have no proper suckers; and the rays are not constituent portions of the body, containing part of the stomach and intestine as in the true Star-fishes, but imperforate appendages to it.

ANGLED CRAB.

Crouching among the rubbish, with all its long limbs snugly packed together, as if hoping to find safety in being overlooked, we see a strange form of crustacea, the Angled Crab. Vain hope! How can a creature of that bizarre form, and of those conspicuous colours, be concealed from notice by merely lying still? Gently touch him behind, and what an enormous length of limb is suddenly thrown out! If, according to the proverb, “kings have long arms,” surely this must be the very monarch of the crabs; and most curiously are they folded when at rest, the fore-arm lying close, throughout its length, upon the upper arm, the elbow projecting far on each side. The carapace is sometimes described as rhomboidal, but this does not give us a correct idea of its form; its outline is rather that of an isosceles triangle, of which the apical half is cut off; the base of this truncate triangle, which is the front side of the shell, runs off into two sharp spines at the angles, and has also a broad projection in the middle, on each side of which are seated the long footstalks of the eyes, and which carries on its front the two pairs of antennæ. The thighs of the true legs are thin and blade-like, so that these limbs all pack one over the other very compactly.

PLATE 26.

P. H. GOSSE, del. LEIGHTON, BROS.

NUT-CRAB. ANGLED-CRAB. ]

The general colour is a light salmon-red, often with the hinder half of the carapace, and the inner sides of the limbs, of a pale buff. The eyes (not the stalks) and the movable finger of each hand, which is slender and elegantly curved, are polished black.

Not uncommon with us, it is not very often seen even by the naturalist, as it seems to be properly an inhabitant of deep water. Occasionally it is washed ashore on the beach by a heavy sea; but this is accidental. Montagu first ascertained it to be British by finding it at Kingsbridge, near Plymouth. Mr. Couch finds it common on the Cornwall coast, together with an allied, but certainly distinct, species, the G. rhomboides of the Mediterranean, to be identified by its lacking a second spine behind each angular one, which is well marked in our species. Though essentially a southern form, it occurs on the Dublin coast, and that in sufficient number to have obtained a popular appellation,--that of “Coffin-crab;” the term “coffin” being possibly a word of the Irish tongue, meaning something very different from that which it suggests to our ears.

Cranch records, as a curious habit of the species, that “they live in excavations formed in the hardened mud, and that their habitations, at the extremities of which they live, are open at both ends.” This description implies a habitat above low water, if not above tide-marks; for where else could “hardened mud” be found? or if it were found in the deep water, how could it come under the observer’s cognizance? However, I know that many marine creatures are littoral in some localities, which are exclusively deep-water subjects in others.

Several observant naturalists have noticed the frequency with which the species is obtained from the stomachs of the larger ground-feeding fishes,--the cod especially. Mr. Ball has taken four at a time from a single cod in Youghal shambles. This is a well-known source for procuring rare specimens of the inhabitants of the deep, particularly Crustacea and the shelled Mollusca; for the fishes are expert and persevering and successful collectors of natural history, and are continually picking up objects for which the naturalist would almost give one of his eyes. Mr. Gordon of Elgin, some years ago, gave a long list of Crustacea, many of them of great rarity, which he had procured from stomachs of cod-fish, “through the agency of Widow Scott and her son John, of the fishing village of Stotfield,” on the Moray Firth. His remarks are suggestive, not only to those residing on the coast, but to the denizens of inland towns. “By a small douceur to the fisherman’s family, and by the assistance of the fish-curer on the coast, the fishmonger of the large town, or of some acquaintance in the fishing village, it is believed that almost any number of these now useless receptacles [viz., cod-stomachs], could be obtained. It may excite at first a little nausea to open up and examine these omnivorous reservoirs, but this will soon pass off; and were it of longer continuance than it is, the stores to be unfolded would amply compensate for all the disagreeable feeling that may for a time arise. It is not only the crustacean that is thus gathered from the inaccessible depths of the ocean, but often the rare shell, with its still rarer inhabitant. The radiated animal and the curious zoophyte will also be found congregated together there; all of them, no doubt, at times mutilated or partly digested, but not unfrequently fresh and complete, as if newly past the voracious jaws.”

NUT-CRAB.

Two or three specimens of another curious crab are also in our haul. Unlike the Gonoplax, the little Nut-crab is not by any means conspicuous in a chaotic heap like this; it requires a sharp eye, and one familiar with the form, to discern him. Remarkably sluggish, he remains motionless; his tiny limbs are almost concealed under the edges of his shell; his body is destitute of sharp angles; its colour is a dull white: in fact the eye might roam over it a dozen times without supposing it anything more than an irregular rubbed quartz pebble.

Yet when you pick it up, it is a pretty little Crab. The form of the body is unlike that of any other of our genera; indeed the type of which it is a representative, though largely developed in the tropical and sub-tropical seas, scarcely reaches to our shores. Some of the allied species in the hotter parts of the globe, are very curious, such as the Calappa, a crab in which the very short limbs are so closely packed to the body, and so wholly concealed by the smooth and rounded shell, that the curious sailor often picks it up and pockets it, as a pretty white stone, little suspecting that he has a living Crab in his fob. And there it lies for hours, perhaps, till he pulls out his supposed pebble, which has not ventured all the while to attempt to crawl.

I believe almost all we yet know of the habits of the timid little Nut-crabs is derived from the portrait that I drew of one of them some years ago, from specimens that I obtained at Weymouth. Since then I have repeatedly kept it in captivity for long periods at a time, and indeed I have one or two now. Yet I have little to add to the sketch I then drew of its manners. It is inert, folding its tiny legs on itself when touched, and remaining motionless for some time. It buries itself in the gravel, descending backwards: this is a somewhat slow process, suited to its usual phlegmatic habit. It brings its hindmost pairs of feet on each side together; then thrusting down their united points, opens and expands them, forcing apart the gravel; at the same moment the posterior part of the body is brought down into the hollow thus made, and the action of the feet is repeated. The process is continued until the hinder parts are covered and the muzzle alone is visible, with the two claws. Thus it sits quite still, reminding one of a toad, the broad triangular pedipalps that fit so close occasionally opening, like the folding-doors of a tiny cabinet, and allowing the palpi to be thrust out to wipe the minute eyes. The face, when examined with a lens through the glass walls of the aquarium, has a most funny expression, being singularly like that of an ancient man.

Like many marine animals, Ebalia uses the hours of the night as its chief season of activity. As long as the candles are in the room, it remains pretty still, but as soon as darkness reigns, it sets out on its travels. Not indeed with the railway pace of some of its fellows does our little ancient travel; he is but a “slow coach;” but he gropes about among the pebbles, and is usually found the next morning, buried at some distance from the point where the previous evening had left him.