2TG CATALOGUE OF THE BLASTOIDEA. 



together. Mouth very small. Anus triangular pyriform, with a thickened edge. 

 Ornament unknown. Column unknown. 



Remarks. P. nobile is the largest species of the genus we have met with, reaching 

 four cm. in height, and is intermediate in character between P. Verneuili and P. acutum 

 (PI. XIV. figs. 8-11). It may, however, be at once distinguished by the great number 

 of its hydrospire-slits, which give to the sides of the sinuses quite a hackly appearance. 

 P. nobile resembles the first of the above-named species in the form of its plates and 

 ambulacra, and in the arrangement of the hydrospire-slits ; but in addition to the 

 character just mentioned, it differs in possessing a truncated summit (PI. XI. fig. 1), 

 for the crests of the deltoid plates do not slope downwards towards the peristome, 

 as in P. Verneuili (PI. XL fig. 5). In this character, however, P. nobile resembles 

 the much smaller P. acutum (PI. XIV. fig. 10), though readily distinguishable from 

 it by the form of its radial sinuses and by its narrow ambulacra. We believe that 

 P. nobile presents the very largest development of the hydrospires which is possible 

 in a Blastoid, 



Locality and Horizon. Colle, near Sabero, Province of Leon, Spain : Calcaire 

 d'Arnao, Lower Devonian. (Presented by Dr. P. H. Carpenter, F.R.S.) 



2. SPECIES FROM THE CARBONIFEROUS. 



Ph.enoschisma acutum, G. P. Sowerby, sp. 



(PI. XIV. figs. 10-12.) 



Pentatrematites acuta, G. B. Sby., Zool. Journ. 1834, vol. v. no. 20,p. 45G,t. 33.Suppl.f.6a-c. 

 Pentremites acutus, Phillips, 111. Geol. York. pt. 2, 1836, p. 207, t. 3. f. 4-5*. 

 Pentatrematites acutus, Roemer, Archiv f. Naturgesch. 1851, Jahrg. xvii. Bd. i. p. 358. 

 Pentremites acutus, Dujardin & Hupe, Hist. Nat. Zooph. Echinod. 1802, p. 93. 

 P/icenoschisma acutum, E. & C, Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 229. 



Sp. Char. Calyx small, acutely pyramidal, rapidly tapering below ; summit sub- 

 truncate ; section pentagonal, with flat or straight, non-lobate sides ; interradial 

 processes truncated inwards, not projecting above the summit. Basal plates 

 forming an elongated cup resembling a bouquet-holder, each plate being acutely 

 angular in the middle line. Radial plates elongate, arched, the bodies angular in 

 the middle line, but slightly longer than the limbs ; sinuses wide and deep, with 

 steep sides. Deltoid plates relatively large and rhombic, the posterior one simply 

 pierced by the anus near its proximal end, but not otherwise modified. Ambulacra 

 elongately petaloid ; lancet-plate narrow, especially at its distal end, deeply excavated 

 for the side plates ; the latter are relatively large and oblong, or inclined to wedge- 

 shaped ; ambulacral groove deeply channelling the lancet-plate at its proximal end. 

 Hydrospire-slits four or five, excavated in the substance of both radial and deltoid 

 plates, usually only one completely exposed in each area when the side plates are 

 in position ; minute spiracles probably present at the central ends of the ambu- 



