38 THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS Occurrence.—Lower Carboniferous, Tournai, Bel- OROPHOCRINUS SIRIUS (White) gium. Plate 18, figures 8-9 Type.—Topotype, S3,230, one specimen, Springer col- Pentremites Sirius WHITE, 1862, 1865, p. 20, fig. 3. lection, U. S. National Museum, Washington. Description.—The holotype is crushed almost flat, Fg 40 37 41 FIGURES 36-41. Species <strong>of</strong> Orophocrinus vox SEEBACH, from Lower Mississippian, North America, and Lower Carboniferous, Europe. 36-39. 0. stelliformis (OwEN & SHUMARD), Lower Burlington Limestone, Burlington, Iowa (U.S. Natl. Mus. neoholotype and paratypes, no. S4,961); 36, plate arrangement at summit <strong>of</strong> calyx, X22.5; 37, anal area <strong>of</strong> neoparatype, X40; 38, stem impression, X22.5; 39, part <strong>of</strong> "A" ambulacrum, showing main and outer side plates and food grooves, X45. 40. 0. orbignyanus (DEKoNiNcx.), Tournaisian, Belg. (U.S. Natl. Mus., no. S3,229); part <strong>of</strong> "A" ambulacrum, showing main and outer side plates, X30. 41, 41a. 0. puzos (Münster), Tournaisian, Tournai, Belgium (U.S. Natl. Mus., no. S3,230); 41, base <strong>of</strong> calyx showing basal plates, X17.5; 41a, part <strong>of</strong> "B" ambulacrum, showing main and outer side plates, X30. [Explanation.—"A," amb.; An, anal opening; Bf, brachiolar facet; Bp, brachiolar pit; D1, deltoid lip; ED, epideltoid; Fg, main food groove; HD, hypodeltoid; L, lancet; 0, oral plate; OSp, outer side plate; RI, radial limb; SFg, side food groove; Sp, main side plate; Ss, spiracular slit: Z, azygous basal.]
BLASTOID STUDIES 39 calyx about 10 mm. in diameter. The prominent feature that distinguishes this species from all others is the elongate winglike extensions <strong>of</strong> the radial limbs outward from the calyx. Occurrence.—Lower Mississippian, Burlington Limestone, Burlington, Iowa. Type.—Holotype, 379, Harvard Museum <strong>of</strong> Comparative Zoology, Cambridge, Mass. OROPHOCRINUS VERUS (Cumberland) Plate 16, figures 7-9 Mitra vera CUMBERLAND, 1826, p. 31, pl. B, figs. 1-2. Description.—Calyx calcitic, club-shaped in side view, 15 mm. long by 13 mm. wide, pelvis longer than vault. This species is distinguished from all others by its short, wide calyx and pelvis slightly longer than the vault. It is similar to Orophocrinus puzos, which has a shorter pelvis and longer vault. Occurrence.—Lower Carboniferous, Mountain Limestone, Lancashire, England. Type.—Plesiotype, S3,237, one specimen, Springer collection, U. S. National Museum, Washington. Genus PENTREMITIDEA d'Orbigny, 1849 Type-species, by original designation.—Pentrernites pailletti VER- NEUIL, 1844. Generic diagnosis.—Fissiculate blastoids with eight hidden hydrospire fields that open into spiracular slits, approximately eight hydrospire slits in each field, with a superdeltoid, subdeltoid, and hypodeltoid on the anal side, hydrospire absent on the anal side, lancet covered by side plates, with possible inner side plate present; calyx steeply conical in side view, with narrow deep sinuses. Devonian, Spain. Remarks.—The genus Pentremitidea was probably derived from a form like Deltoschisma, the subdeltoid being formed by fusion <strong>of</strong> the two cryptodeltoids, the sinuses closing to form spiracular slits, and the anal hydrospire fields becoming atrophied. PENTREMITIDEA PAILLETTI (de Verneuil) Plate 2, figures 1-11; text-figs. 42-45 Pentremrtes pailletti VERNEUIL, 184413, p. 216; 1844a, p. 213, pl. 2, figs. 4 - 5. Description.—Calyx calcitic, conical in side view, pentalobate in top view, 16 mm. long by 9.5 mm. wide, with vault 2 mm. long, pelvis 14 mm. long, and pelvic angle on basals 25 degrees and on radial bodies 40 degrees, with periphery at radial lips. Stem round, small, crenellar, broken in described specimen but present in another one. Basal circlet conical in side view, rounded pentagonal in basal view, 8 mm. long by 7 mm. wide, gradually tapering aborally. Radials five, constricted, broadly pentagonal in side view, lobed in top view, each 9 mm. long by 3.75 mm. wide, with short, narrow, steep-sided sinus 3 mm. long by 2.5 mm. wide. Radial limbs shorter on the anal side than on the other four sides; radials overlapping deltoids. Deltoids four, short, not visible in side view, each 1.75 mm. long by 1 mm. wide, lancet-shaped, with open spiracular slits along ambulacral margins, deep septa, and prominent V-shaped deltoid lips. Approximately eight hidden hydrospire slits are present on each side <strong>of</strong> each deltoid except in the anal area, where hydrospires are lacking. These slits extend to the radial limbs approximately at right angles to the radiodeltoid sutures, opening into each spiracular slit along the ambulacral margins. On the anal side three anal deltoids occur, an elongate V-shaped superdeltoid, upon which a U-shaped subdeltoid rests aborally on the adorai end <strong>of</strong> the anal opening, and a pentagonal hypodeltoid (missing, but facets present) that covers the subdeltoid limbs and abuts against the adjacent radial limbs. Ambulacra five, short, moderately wide, each 4.5 mm. long by 1.75 mm. wide, with lancet covered by side plates, 18 side plates to each ambulacrum, and 45 side plates in 10 mm. length <strong>of</strong> an ambulacrum, if extended. Each primary side plate is elongate abmedially-admedially, quadrangular, with a subtriangular secondary side plate on the admedial-adoral bevelled corner. There appears to be a small triangular inner side plate adjacent to the main food groove, between primary side plates, with apex <strong>of</strong> triangle at suture between adjacent side plates. Approximately four main cover-plate sockets correspond to each side plate along the main food groove, and four or five side cover-plate sockets along each side food groove. The surfaces <strong>of</strong> the calyx plates are ornamented with fine growth lines parallel to plate margins. Remarks.—The many species referred to Pentremitidea do not fit in this genus and must be reclassified in other genera, such as Hyperoblastus, Cordyloblastus, and Deltoschisma. Except for Hyperoblastus, it is common to find species <strong>of</strong> these genera mixed in the same lot <strong>of</strong> specimens in a museum. Hyperoblastus occurs in North America, and the others in Europe. Occurrence.—Devonian, Calizas de Ferr<strong>of</strong>ies, Asturias; Calizas de Arnao, near Sabero (Leon), Spain. Types.—Topotypes, 297, 11 specimens (large one used for description), Schultze collection, old no. 2352, with specimens <strong>of</strong> other genera, Sabero, Harvard Museum <strong>of</strong> Comparative Zoology, Cambridge, Mass.; 547, seven specimens, de Koninck collection, old no. 2353, Asturias, Harvard Museum; S3,622, three specimens, S3,62I, one specimen, Springer collection, Sabero, U.S. National Museum, Washington; 13,876, six specimens, one <strong>of</strong> which belongs to Deltoschisma, Gurley collection, Asturias, Walker Museum, <strong>University</strong> <strong>of</strong> Chicago.
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