Catalogue of the Blastoidea in the Geological Department; With an Account of the Morphology and Systematic Position of the Group, and a Revision of the Genera and Species. (Illustrated by 20 Lithographic Plates,&c.) (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1886 Excerpt: ...of this species (PI. IV. figs. 8, 9), and is more pronounced than in its nearest allies P. Lusitanica (PI. IV. fig. 12) and P. Eifelensis (PI. V. fig. 2), especially the latter. The ambulacra and radial sinuses are relatively much shorter than in the former type, and the radial angle differs a good deal (PI. IV. figs. 9, 11). The calyx is also more slender, and lacks the distension visible in P. Lusitanica just below the lips of the radial plates; while the general form and the wider sinuses separate P. Paillettei from P. Eifelensis (PI. V. figs. 1, 2). Owing to a curious error the former species has been referred to as Pcntremites Dutertrii in Roemer's well-known Monograph l. He gives as a reference L'Institut, 1844, xii. p. 216, but we find that the Blastoid mentioned on this page is really P. Paillettei, the name Dutertrii being employed for a species of Leptaena. Locality and Horizon. Colle near Sabero, province of Leon, Spain: Calcaire d'Arnao, Lower Devonian. De Verneuil and Barrois 2 also give Ferrones, Asturias, in the Calcaire de Ferrones, and the latter further mentions Luanco, in the Calcaire de Moniello. Pentremitidea Lusitanica, E. & C. (PI. IV. figs. 11, 12, 15; PI. V. fig. 20; PI. X. fig. 1.) Pentremitidea Lusitanica, E. & C, Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 223. Sp. Char. Calyx clavate-pyriform, elongate, expanding gradually upwards; base elongate and pointed; summit truncate. Basal plates only a trifle shorter than the radials, forming an elongated cup, the lower portion of each plate bearing a strong central ridge, which assists in forming the ornamentation, but a transverse fold is not present. Radial plates rather narrow, elongate, and arched from the lips downwards along the body of each plate; three impressed lines ...