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Eciiinodermata.] LOWER PALAEOZOIC RADIATA. 61 and rather small in proportion to the disk. The buccal apparatus is composed of ten parts or processes, arranged in pairs; half of each springs from the origin of each arm in a diverging manner, and meets the corresponding half to form a lanceolate tooth-like projection, deeply indenting the cavity of the mouth. Of how many separate ossicles each of the buccal processes was composed, the specimen affords but very indistinct indication. They seem to affect a slightly falcate form at their extremities. The arms were composed of alternating somewhat quadrate ossicula, the sides of which were deeply indented superiorly, in order to form spiniferous crests. The spines were apparently short, and not equal in length to the length of an ossicle; obtuse, and few in a row. The under surfaces of the brachial ossicula were not indented laterally. The central portions of the upper surfaces of the brachial ossicles were hollowed out slightly, and the sutures between them deeply impressed. About twelve of the brachial ossicles were imbedded in the disk, and the parts of the dorsal surface of the latter, corresponding to the arms and central skeleton, do not present traces of scales, a feature seen in existing Euryales. “ The dimensions of Professor Sedgwick’s specimens are as follows:—Breadth of disk, 0,| tIls inch. Average breadth between the arms, 0,| ths inch. Breadth of an arm, at its junction with the body, 0i, th inch. “Locality and Geological Horizon.—Silurian, from Ludlow rocks at Docker Park, near Kendal, West moreland; associated with Encrinites, and at Benson Knot, also near Kendal, in hard sandstones, full of characteristic Ludlow fossils. Collected by the Rev. Professor Sedgwick, and Mr John Ruthven.”—(ProfE. Forbes' note on Silurian Starfishes). 9th Ord. Cystidea. Body enclosed in an ovate bag covered by numerous polygonal ,calcareous, plates; attached by the base, or a small stem, to foreign bodies; mouth at the upper or distal end, opposite the point of attachment; ovarian opening pyramidal, usually pentagonal, and formed of five triangular plates, situated between the mouth and the base, nearer to the former; anal opening small, a little to the right side, midway between the mouth and ovarian pyramid ; no free arms, nor ambulacra. Genus. CARYOCYSTITES ( V. Buck.) Gen. Char.—Spheroidal, pelvis small, hexagonal, of two large pentagonal, and two tetragonal, plates, half the size of the others, above which rests a row of six pentagonal plates with pointed summits, alternating with and above which are three more rows of large polygonal plates, forming a closed cup; mouth opposite the point of attachment; ovarian apparatus nearer to the mouth than the base, situated in the line drawn through the intersection of the two large pelvic plates to the mouth; anus close to the mouth, and a little to the right of the ovaries; surface with strong rhombic stripe from centre to centre of the plates at right angles to their sides. Caryocystites Davisi (M r Coy). PI. 1. D. fig. 5. Ref.—M c Coy, Mem. Geol. Surv. Vol. II. Pt. 2. p. 513. t. 21. f. 4 and 5. Sp. Ch—Spheroidal, most gibbous on the left side (or that containing the ovary), slightly flattened on the opposite side; plates slightly convex, radiated by thick ridges passing from centre to centre through the middle of each of the straight sides of each plate; (in some states of preservation each ridge appears double or triple, but still forming a simple ridge-like bundle); columnar adherence strong, one line in diameter; height of body, eight lines; length (at right angles to middle of height) seven lines; width six lines; ovarian opening oval, one and half lines long, and less than its length from the mouth; anus large, very close to the mouth, nearly one line in diameter; from centre to centre of lateral plates about three lines. As I have remarked (see supra) this Cystidean resembles the Echinosphcerites Balticus in the sim plicity of the ridging of the plates and the smoothness of the intervening triangles, but I pointed out