Fig. 16, is another slab of pentacrinal Lias limestone, with portions of a stem and numerous side-arms: these are generally electrotyped, as it were, with a brilliant pyrites, giving a rich metallic lustre to the animal remains. In the British Museum there are many splendid specimens of this highly interesting family of Radiaria. I would especially direct the intelligent visitor's attention to a slab of stone, many feet in height and breadth, on which a group of Pentacrinites is displayed, as palpable and perfect as if the animals were sporting in their native element. This matchless specimen is from Germany. Fig. 17. One of the small auxiliary lateral tentacles of a Pentacrinite. [Illustration: Plate LII.] PLATE LII. Pentacrinites. Fig. 1. This specimen displays the usual appearance of the mode in which the arms of Pentacrinites are spread out in relief on the pyritous lias limestone of Charmouth. Fig. 2. The arms, from the upper part of the receptacle to their third or fourth subdivision of the Briaræan Pentacrinite. Charmouth. Fig. 3. A small specimen, showing the ramifications and delicacy of the extremities of the arms or tentacula. Fig. 4. "A fossil body, supposed to be a species of oval encrinite."--_Mr. Parkinson._ This fossil is certainly a coral, probably some species of Turbinolia, from the Devonian formation. [Illustration: Plate LIII.] PLATE LIII. Fossil Star-Fishes and Echini. The radiated animals popularly called Star-fishes, from their stellular figure, are so abundant along our sea shores, that the nature of the common five-rayed species (_Asterias_, or _Uraster rubens_)[47] must be familiar to most of my readers. This species belongs to the group in which the rays are elongated, and far exceed in length the diameter of the disk; in another subdivision (the _Goniaster_, or Cushion-star), the body is angular, and the lobes or rays are short, and do not exceed in length the diameter of the body. In another group (the _Comatula_, or Feather-star), the rays are fringed with long jointed tentacula, which divide and subdivide like those of the Crinoidea; and these star-fishes may, in fact, be regarded as free Lily-shaped animals.[48] There is another tribe in which the arms are elongated into slender rays, without grooves or tentacula; these are called the Serpent Star-fishes (_Ophiura_). Species of all these groups occur in a fossil state.[49] [Footnote 47: See Professor Forbes's delightful "History of the British Star-Fishes."] [Footnote 48: In the young state the Comatulæ have a jointed stem, and are attached to other bodies; being in this stage true Crinoideans.] [Footnote 49: Medals of Creation, p. 332.]