CHAPTER X. ECHINODERMATA (Star-fishes). ON many a shingly beach where the limestone formation occurs there may be found small perforated pebbles, which, rounded and polished by the action of the waves, resemble beads of stone. In the days of Popish superstition, these were supposed to be fashioned by an imaginary "Saint Cuthbert" for the rosaries with which prayers and invocations were meted out by tale. One of the rocky islets that speckle the tempestuous sea of Northumberland, was assigned to the special manufacture of these useful articles - "On a rock by Lindisfarn Saint Cuthbert sits, and toils to frame The sea-born beads that bear his name."-Marmion. In the same districts where these occur, the wondering peasantry have often admired what they call Lily-stones, a class of fossils to which modern geologists apply the equivalent term Encrinites; the stony stem, and a crown of rays bending in sigmoid curves, resembling the stalk and elegant bell-shaped blossom of a liliaceous flower. Now the "beads" are nothing more than the joints of which the stem of the Encrinite is composed, and the Encrinite itself is the fossil skeleton of an ancient Starfish. The abundance of these animals in the primeval seas may be inferred from the profusion of their remains ; vast strata of marble, extending over large regions in the northern parts of both hemispheres, being made up of these "lily-stones," as absolutely, to use the graphic simile of the late Professor Buckland, "as a corn-rick is composed of straws." common. The form, however, is as rare now as it was anciently Some years ago a fine specimen in a living state was brought up by the dredge in the Caribbean Sea; and as the stem was violently torn asunder, the basal portion being wanting, it is inferred that the base is immoveably fixed to the rock like a sea-weed. With the exception of a few fragments found on divers occasions, and carefully treasured in national museums, this is the only recent specimen of any considerable size which has been But a minute kind has been ascertained to inhabit our own seas, a tiny Encrinite about three-quarters of an inch in length. It is described as bearing "five pairs of beautifully pinnated arms, and as of a deep rose-colour, dotted over with brown spots, which are regarded as the ovaries. It is dredged up," observes Mr Patterson, "on many parts of the Irish coast, and is occasionally found upon the strand. The first specimen we ever possessed seen. was taken on the beach about six miles from Belfast, and was brought to that town alive. Anxious to secure so attractive a specimen for the cabinet, we placed it in a shallow vessel of fresh water, and found, to our surprise, that it emitted a fluid which imparted to the water a roseate tinge." But the discovery of this little animal, interesting as it was for its own sake, was rendered more interesting by a subsequent discovery. The Encrinite proved to be only the youthful condition of a well-known elegant Star-fish, called from its colour and its plumose crimson rays arrayed in five pairs, the Rosy Feather-star. But this is a freeroving species, swimming at will through the sea, by the periodical contraction and expansion of its incurved rays, in the manner of a Medusa. The metamorphosis of the little Encrinite to the Comatula, as the Feather-star is technically named, was at first but a matter of probable conjecture. It has, however, been verified by actual observation. "When dredging," observes Professor Forbes, the learned historian of British Star-fishes, "in Dublin Bay, in August 1840, with my friend Mr R. Ball and Mr W. Thomson, we found numbers of the Phytocrinus, or polype state of the Feather-star, more advanced than they had ever been seen before; so advanced that we saw the creature drop from its stem and swim about, a true Comatula; nor could we find any difference between it and the perfect animal, when examining it under the microscope." + And thus was completed what the same zoologist designates as one of the little romances in which natural history abounds; one of those narrations which, while believing, we almost doubt, and yet while doubting, must believe." * "Zoology for Schools," i. 47. |