5. Asterina gibbosa.
6. Palmipes membranaceus.
7. Palæmon serratus.
Stars of this class, having the power to dislocate their structure, are popularly known as brittle Stars. Some affect to consider this faculty not so very wonderful; but let such suppose for a moment some higher animal—a man, for instance—gifted with a capacity for exploding his trunk and limbs into moderately-sized fragments—into joints, as a butcher would say—at any slight provocation, and then the character of such a power would appear very sufficiently extraordinary. It is possible that the fragments of the disruptured Star-Fish have the power, in each separate fragment, of renewing the absent portions, and that each portion thus becomes a perfect fish, the dissevered portions having been noticed to retain their vitality long after their separation. We know that the little Garden Lizard has the power of dislocating his tail without effort, and leaving it between the thumb and finger, when he is playfully caught by that appendage; and, also, that he has the power of renewing his caudal extremity within a very short period. It is thought, therefore, not impossible, reasoning by analogy, that the Star-Fish may possess powers of a similar kind, of a somewhat more extensive character.
The Amnion Star-Fish, called sometimes Five-fingered (Asterias rubens), belongs to the division Echinodermata, that is, skinned like the Hedgehog.
The Sea-Egg, Sea-Urchin, or Egg-Urchin, as it is sometimes called, belongs also to the Echinodermata, or Hedgehog-skinned class, and form interesting objects in the Aquarium; the flat species exhibiting much more evidently their close affinity to the Star-Fish tribe, than those of the more common spherical form.
To revert to other classes that occur to me as suitable objects for an Aquarium, I may mention the “Red-noses,” as they are graphically termed (Saxicava rugosa), a colony of which, peeping out of their holes in the rock, would form a very striking object; and if a piece of their native rock could be detached sufficiently deep not to disturb them in the recesses of their tube-like burrows, their removal “en bloque” would not be difficult. When touched, the Red-nose squirts a stream of water at you in defiance, and darts back into his cavern. He is a small bivalve, having his inner or immediate home within two rough brown shells. The double-tubed proboscis with which he is furnished is extended, when in search of food, to the mouth of his cave, in which position the appearance of its ruddy terminus has given to this tribe the characteristic name of “Red-noses.” How he contrives to bore a hole in the solid rock, with any of the soft pulpy members with which he is furnished, appears a mystery. Other Conchifers have, however, similar capabilities, their ingenuity not being confined to rocks, and their industry not being always harmless. Such, for instance, is that of the Teredo, or Ship-worm, a species of which has long proved so inimical to the formation of a Russian fleet in the Black Sea—the late war having, however, proved a far more serious impediment to the development of that portion of the Russian navy.
The Sea-Leaf, formed of twenty thousand or more cradles for young Polypes, is also a curious object. It is the Polyzoön, sometimes called the Hornwrack.
A few of the translucent Medusæ, in a young stage of their existence, might be procured and tried, though their transport would be difficult; and a group of creatures, of the genus Zoöthamnium, forming, as they do, an object like a little tree of glass, covered with trumpet-shaped bells, of the same crystalline aspect, each exhibiting its rotating circle of minute cilia in rapid motion within, would form a singular and beautiful complement to the wonders of the Aquarium, if its removal from its native depths, and its location in its new home, could be successfully managed.
