DESCRIPTIONS OF THE BPE0IB3. 253 



slightly arched, obliquely truncated above; sinuses relatively broad, tapering 

 gradually; lips prominent, but hardly extending as low as the truncate base; 



interradial sutures on the flat sides, not in concavities. Deltoid plates clongately 

 and irregularly rhombic, slightly concave in the middle line, sometimes with an 

 ill-defined longitudinal ridge in the concavity. Ambulacra Bubpetaloid, projecting 

 a little above the sides of the sinuses; lancet-plates exposed for a portion of their 



length ; side plates fifteen to twenty. Ilydrospires unknown. Spiracles oval- 

 triangular, opening more or less horizontally, the four smaller ones traversed by 

 incomplete, but well-marked septa. Mouth small. Ornament consists of rather 

 strong granules arranged in lines parallel to the margins of the plates. 



Remarks. This little species is intermediate in its characters between G. ellipticua 

 and (i. campanulatus. It possesses the elongated calyx of the former (PI. VIII. 

 tigs. 16,19), and the truncated and flattened base of the latter type (PL VIII. rig. 13). 

 The prominence of the constricted apices of the deltoids gives to <i. McCoyi a rather 

 marked appearance, and they specially assist in giving a truncated look to the summit 

 (PI. X. fig. S). The spiracles would, at first sight, appear to be constructed as in the 

 type for which we have proposed the name of Mesoblastus, and the strong septa 

 visible in them would favour this idea. But they are true perforations of the 

 deltoids, and are formed without any assistance from the side plates. 



It affords us much pleasure to name this species in honour of Prof. F. McCoy, as 

 one of the pioneers of British Palaeontology. 



Locality and Horizon. Clitheroe, Lancashire (Presented by the late J. Rofe, Esq., 

 F.G.S.) : Carboniferous Limestone. 



Graxatocrixus ELLirncrs, G. B. Sowerby, sp. 

 (PI. VI. fig. 21 ; PI. VIII. figs. 16-20 ; PL X. figs. 12-1G ; PL XVII. figs. 6, 7.) 

 Pentremites elliptica, G. B. Sby., Zool. Journ. 1826, vol. ii. no. 7, p. 317, 1. 11. f. 4 (4 figs.). 

 Pentremites ellipticus, Phillips, Geol. York. pt. 2, 182G, p. 207, t. 3. f. 6-8. 

 Pcntrcmiti'S cl/i/j/irns, McCoy, Synop. Carb. Lime. Foss. Ireland, 1841, p. 174. 

 Pentatrematites ellipticua, Roemer, Archiv f. Naturgesch. 1831, Jahrg. xvii. Bd. i. p. 360. 

 Pentremites ellipticus, McCoy, Brit. Pal. Foss. 1851, fasc. 1, p. 12k 

 Pentremites ellipticus, Dujardin & Hupe, Hist. Nat. Zooph. Echinod. 18G2, p. 93. 

 Pentremites ellipticus, Rofe, Geol. Mag. 1865, vol. ii. t. 6. f. 7. 

 Granatocriims ellipticus, E. & C, Ann. & Mag. Nat. Hist. 1882, vol. is. p. 239. 



Sp. Char. Calyx elliptical, acorn-shaped, or elliptical subglobose ; summit rounded 

 and contracted ; base narrow and concave, with a wide, shallow, central depression ; 

 section faintly pentagonal or almost round, with the sides flat, periphery nearly 

 equatorial. Basal plates small, outwardly concave, and confined to the central 

 depression. Radial plates large, broadly pentagonal, very narrow below, expanding 

 upwards, and extending over more than half the height of the calyx ; bodies very 



