this single colony, on a submarine island, was about equal in number to the population of Scotland."

The spectacle presented by one of these polypidoms, when in a saucer containing sea-water, and placed under the microscope, is full of interest. Whether the animals lie in a state of repose, or with the tentacula expanded and in full activity, their aspect and motions are all indicative of happiness. This conviction increases the pleasure with which we regard them; for truly has the poet said,—

"The heart is hard in nature

that is not pleased

With sight of animals enjoying life,

Nor feels their happiness augment his own."-Cowper.

CLASS IV.-RAYED ANIMALS.

RADIARIA.

"The firmament

Was thronged with constellations, and the sea
Strown with their images."-JAMES MONTGOMERY.

WE have now reached the fourth, or highest class of the radiated animals. In these the radiated structure is not confined to the nervous system, nor to the arrangement of the parts surrounding the mouth: it extends to the form of the body, and may be seen in the common Jelly-fish,

which is so abundant on our coast, or in any one of the various Star-fishes (Fig. 15). The two examples just men

tioned point to an obvious and very natural division of the class. The soft and jelly-like tribes belong to a group of animals whose domain is the wide and open sea; the Star-fish and the Sea-urchin, to a community whose members live at fathomable depths, in the vicinity of land. The covering of each of these groups of animals is suited to the situation which they are destined to occupy; that of the one being soft and membranous, while that of the other is hard, leathery, or prickly.

SEA-NETTLES.-ORDER ACALEPHÆ.

"Those living jellies which the flesh inflame,
Fierce as a nettle, and from that its name;
Some in huge masses, some that you may bring
In the small compass of a lady's ring;

Figured by hand Divine-there's not a gem

Wrought by man's art to be compared to them."-CRABBE.

THOSE who have been in

Fig. 16.-JELLY-FISH.

the habit of bathing in the sea during the warm summer months, may probably have experienced the severe stinging pain caused by the touch of the long threadlike appendages of the Sea-nettles or Jelly-fish (Medusa); and if so, they will understand the reason why the old Greek naturalists gave to them a name signifying "nettles," (Acalépha). They are found in all seas, and please the eye, both by their glassy trans

parency and by their brilliant hues (Fig. 16). In the structure

of their frail and gelatinous bodies there is much to excite our surprise. They seem little else than a mass of vivified sea-water; yet, feeble as they appear, fishes and other small marine animals are quickly dissolved in their stomachs.

Among the animals belonging to the present order, there is a great variety, not only of size but of general structure and appearance; and the diversity that we witness around our own coasts, is increased by species which are inhabitants of warmer latitudes, being occasionally carried to our shores by the winds and currents of the ocean. As one example of these, the little Velella (Fig. 17) may be mentioned. Fixed obliquely across

a bluish oval disc, it exhibits a snowy crest, which has been compared to the lateen-sail of the Malay boatmen. Thus propelled, the living squadrons of this little mariner have been observed while

passing the picturesque headlands of the Giant's Causeway, and the basaltic cliffs of other parts of the County Antrim. The engraving here given of one is copied from an original drawing made by Professor Allman, who remarks:-" The individual who sat, or rather floated for his likeness, was one of a fleet of countless multitudes, which, in the Autumn of

1836, was driven upon the coast of the County of Cork. On the subsidence of the gale, which had been blowing strongly from the south-west, the coast for miles round was strown with the remains of the shipwrecked fleet."

If a

Another species not less attractive is a native of our seas, and may very easily be obtained during the fine weather of summer or autumn. gauze towing-net be attached to a boat, which is rowed gently along, it is probable that, if the net be examined after a short time, there will be

Fig. 18.-BERÖE.

found among its contents some transparent bodies, differing in size, but in general about as large as a boy's marble (Fig. 18). These are members of a family known by the name of Beröe, from one of the sea-nymphs of classic fable. Externally they exhibit ridges like those of a melon, and are in form not unlike an orange or an apple. If gently lifted from the net, and placed in a glass of sea-water, the animals will begin to move by means of eight bands of little paddles (cilia), which extend from the upper to the lower extremity