186 CATALOGUE OF THE BLASTOIDEA. 



(fig. 8), comes right down to the peristome, which is not always the case in that type 

 (PI. IV. fig. 1). It is equally complete, but less wide, in M. Sowcrbii (PL VI. fig. 13). 



J/, angulatus appears to be a rare species, and we are acquainted with but few 

 examples of it. The form of its hydrospires is well seen in PL XVII. fig. 9. 



Locality and Horizon. Bolland District, Lancashire : Carboniferous Limestone. 



Mesoblastus elongatus, Cumber/and, sp. 

 (PL VI. fig. 11; PL VIII. figs. 1-1; PL XI. fig. 15 ; PL XVII. fig. 10.) 



Mitra elongata, Cumber] and, Reliquiae Conservatse, 1826, p. 35, t. a. f. 1-3 (2nd row). 



Pentatrematites oblonga, G. B. Sowerby, Zool. Journ. 1828, vol. iv. no. 13, p. 00; ibid. 

 1835, vol. v. pi. 33 Suppl., f. 3, & f. 4 (?). 



Pentremites oblongtts, Phillips, Geol. York. pt. 2, 183G, p. 207, t. 3. f. 11, & f. 12 (?). 



Orbitremites ? oblongus, T. & T. Austin, Ann. & Mag. Nat. Hist. 1812, vol. x. p. 111. 



Pentatrematites oblongus, Rocmcr, Archiv f. Naturgescb. 1851, Jahrg. xvii. Bd. i. p. 3G2. 



Pentremites oblongus, Dujardin & Hupe, Hist. Nat. Zooph. Echinod. 1862, p. 94. 



Granatocrinus oblongus (pars), E. & C, Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 239. 

 Sp. C/iar. Calyx long and barrel-shaped ; summit truncate, flat, or a little concave ; 

 base widely excavated, but not deeply so ; section pentagonal, with concave sides ; 

 periphery equatorial. Basal plates relatively large, slightly concave externally, with 

 a large columnar facet. Radial plates very long, extending nearly the whole length 

 of the calyx, with the lateral margins parallel ; bodies small, rather concave, 

 assisting to form the shallow basal concavity, bounded by obtuse, ill-defined ridges, 

 which proceed obliquely from the radial lips ; limbs long and narrow, sides sloping 

 at a high angle, upper edges convex ; sinus broad, relatively subpet.doid, margins 

 sharp and prominent ; lips small and projecting ; the lines of the interradial sutures 

 very straight, and in slight concavities. Deltoid plates small, elongately triangular. 

 Ambulacra moderately broad, and of nearly uniform width throughout, rather flat, 

 and sunk below the edges of the sinuses at their upper ends, but rising to a level 

 with them at their apices ; lancet-plate broad, the food-groove exposed for nearly its 

 whole length, wide and open ; side plates oblong, thirty-five or more in number, 

 almost horizontal ; outer side-plates very small. Hydrospire-folds three on each 

 side of an ambulacrum ; sacs large. Spiracles triangular-pyriform, usually with 

 strong septa, opening nearly horizontally. Mouth moderately large. The ornament 

 oi the radial plates consists of a fine granular reticulation arising from the longi- 

 tudinal rows of granules being crossed by transverse strioe, and more pronounced on 

 the lower portions of the plates ; on the radial limbs at the edges of the sinuses are a 

 series of coarse, more or less transverse ridges, or elongated tubercles ; deltoid plates 

 coarsely granular. 



Remarks. This is an elongated and exceedingly well-proportioned species, and 

 anything but common l . The Mitra elongata of Cumberland appears to have been 



Besidi - tin- specimens in the National Collection, we have found one in the Museum of the Grammar 



Si hi "1 it Giggleswick, and another in the Free Public Museum at Ulackburn. 



