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116 BRITISH PALAEOZOIC FOSSILS. [Echinodermata. POLYPORA VERRUCOSA (M c Coy). Ref.—M e Coy, Syn. Carb. Foss. Irel. t. 29. f. 6. Sp. Ch.—Interstices straight, round, nearly half a line wide, equal, bifurcating rarely at less than three or four lines, (often upwards of an inch without branching) ; obverse with four alternating rows of pro minent wart-like pores, about eight or ten in each row to the length of a fenestrule, intervals between the pores marked with waving longitudinal strife; reverse nearly smooth; dissepiments • thin, distant; fene- strules regular, rectangular, oblong, sub-equal, about five times longer than wide, slightly wider than the interstices (three in two lines measured transversely) and about two and a half lines long. This is the only species of the genus in which I have seen prominent-edged pores. Rare in the carboniferous limestone of Derbyshire; the original Irish locality was the lower limestone of Kildare. 6th Class. ECIIINODERMATA. See page 51. 1st Order Crinoidea. See page 52. Genus. POTERIOCRIXUS {Mill.) restricted by Aust. Gen. Clmr.—Column and alimentary canal round, with round axillary side arms; cup conical, formed of pelvis, one row of primary and one row of secondary radials, and an irregular group of three interradials on one side; pelvis of five large pentagonal plates, their bases resting on the upper columnar joint; alternating above these are two obscurely heptagonal and three hexagonal primary radials, alternating over which, are five pentagonal 1st secondary radials (scapulae), between two of which, are two or three small, interradial plates; free rays composed of a few of the secondary radials (arm-joints) as wide, or nearly so, as the 1st (or scapula'). Prof. Phillips and some other authors notice in their descriptions of this genus the existence of a very minute, pentagonal, tripartite pelvis, entirely concealed within the columnar articulation marking the bases of the five plates above considered ‘pelvic’: I have never seen any trace of this supposed, very abnormal, pelvis, and I can state that it does not exist in the Poteriocrinus impressus (Phil.), in which I have seen the base clearly exhibited with the five divisional lines extending to the minute alimentary opening. Poteriocrinus granulosus (Phill..) Ref.—Phill. Geol. York. Vol. II. t. 4. f. 2. 4, 8, 9, 10. Sp. Ch.—Cup obtusely conical, one-third wider than long to the edge of 1st secondary radials (scapula'); pelvis small, pentagonal of five pentagonal plates, twice as wide as long, excavated and radiated at their base to form part of the columnar attachment; between and above these are inserted five pentagonal (or obscurely hexagonal) 1st primary radials, one-third wider than long; alternating over these are five pentagonal 1st secondary radials (scapulae) twice as wide as long; all the plates nearly flat and closely covered with fine granules. Length of cup about half an inch. One of the primary radials is hexagonal and has one of its upper sides so long and nearly horizontal that it seems to support one of the scapulse or secondary radials, and on its shorter side it has the long irregular hex agonal 1st interradial plate, supporting two small lengthened 2nd interradials. Position and Locality.—Common in the carboniferous limestone of Derbyshire.