68 THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS periphery above mid-height, with flat summit and small deep basal concavity. Stem round, crenellar, 2 mm. in diameter, with small round lumen. Basal circlet pentagonal in aboral view, 3.5 mm. wide, concave, in deep basal concavity, with three normally disposed basais, each with a prominent central ridge. Radials five, pentagonal in side view, each 8.5 mm. long by 9 mm. wide, sharply recurved below, with body in basal concavity, with narrow, shallow sinus 5 mm. long by 1.25 mm. wide, and body flaring at radial lips. Deltoids overlap radials. The surfaces <strong>of</strong> the radials and basais are ornamented by fine growth striae subparallel to plate margins. Deltoids four, broadly lenticular, each 32 mm. long by 15 mm. wide, with two hemielliptical spiracles notched in the adorai tip adjacent to the ambulacral margins. On the anal side there are at least three anal deltoid plates and possibly four exposed. The two cryptodeltoids extend around the sides <strong>of</strong> the anal opening and are separated by one or two oral plates on the adorai side <strong>of</strong> the anal opening. The plate adjacent to the anal opening may be a superdeltoid plate. The long quadrangular hypodeltoid, bordered on either side by the cryptodeltoids, is aboral to the elongate diamond-shaped anal opening, and has a low rounded anal lip that rapidly decreases in height aborally. The adorai tip <strong>of</strong> each cryptodeltoid has a hemielliptical spiracle in its ambulacral margin. Thus there are 11 openings around the oral aperture, consisting <strong>of</strong> ten spiracles and a separate anal opening. The ornamentation <strong>of</strong> the deltoids and anal deltoids is the same as in Nucleocrinus. There are two hydrospire folds on each side <strong>of</strong> an ambulacrum, with a moderately long hydrospire canal. On the inner surface <strong>of</strong> the hypodeltoid is an inward-projecting hornlike process. Summit covered by approximately 21 oral plates (Fig. 120). Ambulacra five, linear, each 45 mm. long by 2 mm. wide, recurved below, with lancet covered by side plates, and 22 side plates in a space <strong>of</strong> 10 mm. along an ambulacrum. Inner side plate present, with approximately four cover-plate sockets to each side plate along the main food groove. Side plates disposed as in Nudeocrinus, with one large pore between adjacent side plates along the deltoid and radial margins. Occurrence.—Middle Devonian, Onondaga Formation, Jeffersonville, Indiana. Types.—Plesiotypes, 9,956, ten specimens, the largest <strong>of</strong> which is described above, Gurley collection, Walker Museum, <strong>University</strong> <strong>of</strong> Chicago. ELAEACRINUS VENUSTUS (Miller & Gurley) Plate 28, figures 1-6; text-figs. 122-125 Nucleocrintts venustus MILLER & GURLEY, 1894, p. 63, pl. 8, figs. 26-30. Description.—The description is based on one <strong>of</strong> the syntypes (1,317). Calyx calcitic, ellipsoidal in side view, rounded pentagonal in top view, 16.5 mm. long by 12.5 mm. wide, with flat summit, concave constricted base, and periphery near mid-height. Stem round, crenellar, 1.25 mm. in diameter, in sharp basal concavity. Basal circlet lobed-pentagonal in aboral view, 2.75 mm. in diameter, in sharp basal concavity, with three normally disposed basals. Radials five, pentagonal in oblique basal view, short, each 3.5 mm. long by 5 mm. wide, recurved below, with short, narrow, flat sinus 2 mm. long by 1.5 mm. wide, and broad M-shaped radiodeltoid suture formed at top <strong>of</strong> radial limbs. Deltoids overlap radials. Deltoids four, long, bluntly lenticular, each 14 mm. long by 6 mm. wide, each with a smooth central triangular area with base equalling almost the full width <strong>of</strong> the radiodeltoid suture, bordered on either side by a granulostriate lenticular area, with two slitlike spiracles notched in the adorai tip adjacent to the ambulacra. On the anal side there are at least three, possibly four, anal deltoid plates. A central smooth quadrangular hypodeltoid with raised adorai end is bordered on either side by two granulostriate cryptodeltoids that extend adorally beyond the anal opening (one on each side) with one or two small plates between them adorally from the anal opening One <strong>of</strong> these plates, slightly below the other, is adjacent to the anal opening and may represent a superdeltoid plate. The adorai tips <strong>of</strong> the two cryptodeltoids abut against three other oral plates on the anal side. Each cryptodeltoid has one slitlike spiracle on the adorai tip along the adjacent ambulacral margin. Thus there are 11 openings around the oral aperture, that is, ten spiracles FIGURE PAGE 1-5. Troostricrinus reinwardti (TRoosT), holotype, 33,071 (now 139,105) (figs. 1-3), paratypes, 139,106 (figs. 4, 5), Troost coll., U.S. Natl. Mus.; Middle Silurian, Niagaran, Decatur County, Tennessee; 1, oral view ( X6); 2, "D" ambulacral view (X3.4); 3, aboral view ( X6); 4, anal view showing superdeltoid, cryptodeltoids and hypodeltoid ( X22); 5, polished section with "A" ambulacrum directed upward, oral view ( X4.5) 106 6-8. Metablastus lineatus (SHumARD), neotypes, S4,958 (new holotype, figs. 7,8); S4,957 (new paratype, fig. 6), EXPLANATION OF PLATE 19 Springer coll., U.S. Natl. Mus.; Lower Mississippian, Upper Burlington Limestone, Sagetown, III.; 6, aboral view <strong>of</strong> "C" ambulacrum ( X10); 7, anal view <strong>of</strong> holotype showing exposed cryptodeltoids where hypodeltoid is missing (X6.6); 8, "CD" interambulacral view <strong>of</strong> holotype (X2.2) 79 9. Metablastus varsouviensis (WORTHEN), syntype, 1,885, A. H. Worthen coll., formerly Illinois State Mus., Springfield, now Illinois Geol. Survey, Urbana; Mississippian, Warsaw beds, Monroe County, Illinois; side view <strong>of</strong> one <strong>of</strong> two imperfect types, in rock ( X7.1) 82
UNIVERSITY OF KANSAS PAL FONTOLOGICAL CONTRIBUTIONS FCHINODER MATA, ARTICLE 3 PI.ATF 19 2 7 FAY-BLASTOID STUDIES