The principal type of the Euryalina is the curious and complex _Asterophyton verrucosum_ of Lamarck. They include animals remarkable for the extremely complicated development of their arms--the very multiplied ramifications of these, towards the extremities, being divided into many thousand very slender appendages, the principal use of which is doubtless locomotion, but at the same time they constitute a series of living thread-like fillets which seem intended to seize and close upon the animals which serve as prey to this little flesh-eater. The _Asterophyton verrucosum_, which is represented in Fig. 111, is yellowish; its disk about four inches, its arms sixteen to eighteen. It inhabits the Indian Ocean. Another species, _Euryala arborescens_, is met with on the coasts of Sicily and other parts of the Mediterranean. Nothing can be more elegant than these animated disks, which resemble nothing so much as a delicate piece of lace--a piece of living lace moving in delicate festoons in the bosom of the ocean. ECHINIDÆ. The singular shape of the Echinidæ, or Sea-urchins, and the spiny prolongations with which their bodies are covered, has in all ages attracted the attention of naturalists. Aristotle applied to them the name ἐχῖνοϛ, which signifies urchin. When, however, one sees the body of one of these animals thrown on the sea shore, it is difficult, at first, to find a reason for this designation. The body of the sea-urchin is furnished with a species of spine. It is a sort of shell, nearly spherical, empty in the interior, its surface presenting reliefs admirable for their regularity--an egg-shell sculptured by Divine hands. In order to see the urchin with its spines, it is necessary to seize it in the water at the bottom of the sea, where it rolls and moves its little prickly mass; it is then only that the real urchin, the prickly sea-urchin, is to be seen, bristling with prickles, and strongly resembling, to compare the physical with the mental, those amiable mortals whose character is so well depicted in the saying, "Whom they rub they prick." In his book on "The Sea," Michelet puts the following conversation into the mouth of a sea-urchin: