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Echinodermata.] UPPER PALAEOZOIC RADIATA. 119 plates large, polygonal more or less prominent in the centre; mouth small, excentric; plates of the cup generally marked with radiating rows of small tubercles, and two or three rows parallel with the margin ; interradial (or inter-scapular) plate large, hexagonal. This much resembles the P. rugosus, but the form is more cylindric, the plates thinner, with smaller and more regular tubercles, the interradial plate larger, and the excavation in the scapulae or 1st primary radials for the arms or 2nd primary radials much narrower. Position and Locality.—Abundant in the carboniferous limestone near Bakewell, Derbyshire. Platycrinus megastylus (M' Coy). jRef.—M c Coy, Ann. Nat. Hist. 2nd Series, V9I. IT. p. 247. = P. Icevis Phil. Geol. York. Vol. II. t. 3. f. 14, 15, (not of Miller). Bp. Ch.—Body broad, ovate, visceral portion convex, not much elevated; cup rapidly expanding, conical; pelvis pentagonal, very small, resembling a prominent rim to the very large circular columnar attachment, the diameter of which is three times greater than from its circumference to the edge of the pelvic plate; 1st primary radials (scapula?) slightly convex, even, nearly twice as wide above as below, little wider than long; excavations for the 2nd primary radials (arm-plates) large, nearly half the depth of the 1st or scapula;; capital plates variable in size and number, but large, few, unequal, polygonal, and most of them presenting a large conical protuberance in the centre; entire surface smooth. Length of body ten lines, width between the arms nine lines. This species is excellently figured by Prof. Phillips (Geol. Yorksh.) with a doubtful reference to the P. Icevis of Miller. The latter species is, I believe, generally admitted now to be distinct; but having examined specimens agreeing with the above figure, I find the species to which it belongs differs both from that to which Goldfuss and that to which Mr Austin have referred it by the comparatively enormous size of the columnar attachment, and the narrow prominent rim to which the rest of the pelvis seems reduced. Position and Locality The specimens above described are from the carboniferous limestone of Bolland, where it occurs in company with numbers of the P. pileatus, Gold. (P. antheliontes, Aust.), which it much resembles, but from which it is easily distinguished by the above characters. Platycrinus pileatus (Gold.) Ref. and Syn.—Goldfuss. Nova. Acta. Akad. Nat. Cur. &c. Vol. XIX. t. 31. f. 7. = P. antheliontes Aust. Crin. t. 2. f. 3. Bp. Ch.—Cup expanding rapidly, conic; capital portion depressed; pelvis conical, rounded, columnar adherence small, its diameter scarcely equalling the shortest line from its circumference to the edge of the pelvis; 1st primary radials (scapula;) wider above than below, length and breadth nearly equal, arm-exca vation large, depth rather more than one-third the length of the plate ; surface smooth ; capital plates large, few, polygonal, with a large more or less prominent conical umbo in the centre of most of them; mouth marginal. I do not think with Mr Austin that this is the crinoid figured by Phillips as the P. Icevis of Miller ; I have seen specimens from Bolland agreeing with Phillips’s figure in the great size of the columnar adherence, &c., and which are certainly distinct. (See P. megastylus.) Position and Locality.—Very common in the carboniferous limestone of Bolland. (Bristol is the original locality given by Goldfuss.) Platycrinus vesiculosus (M'Coy). PI. 3. D. fig. 3. Ref.—Ann. Nat. Hist. 2nd Series, Vol. II. p. 246. Bp. Ch.—Body spheroidal, depressed; visceral portion hemispherical, deeper than the cup; pelvis penta gonal, small, flattened; 1st primary radials or scapulae small, rotundato-quadrate, one-third wider than long, very thick, gibbous, slightly concave in the centre, lower edge hanging below the pelvis, excavation for the first arm-joint (or 2nd primary radial) very small, round, marginal, less than one-third the depth of the 1st primary
