UNIVERSITY OF KANSAS PAL FONTOLOGICAL CONTRIBUTIONS PLATE 28 FC!-IINODFRMATA, ARTICLE 3 FAY-BLASTOID STUDIES 'o
BLASTOID STUDIES 89 with center at junction <strong>of</strong> interradial suture with the radiodeltoid suture. Ambulacra five, linear, with lancet exposed along the median one-third <strong>of</strong> its width almost to the aboral end <strong>of</strong> each ambulacrum. Side plates normally disposed, with approximately five cover-plate sockets to each side plate along main food groove, and two pores to each side plate, one <strong>of</strong> which is almost even with a side plate suture and the other about midway between the side plate sutures. Surfaces <strong>of</strong> calyx plates ornamented by fine granules arranged subparallel to plate margins along growth lines. Occurrence.—Lower Carboniferous, recorded as Devonshire (may mean Derbyshire), England. Type.—Plesiotype, 1,633, one specimen, James collection, labelled Granatocrinus ellipticus, Walker Museum, <strong>University</strong> <strong>of</strong> Chicago. ORBITREMITES ELLIPTICUS (Sowerby) Plate 43, figures 1-3, 10-11; text-figs. 186, 187 Pentremites elliptica SOWERBY, 1825, p. 317, pl. 11, fig. 4. Elaeacrinus ellipticus SHUMARD, 1863, p. 112. Description.—Calyx calcitic, fragmentary, 12.5 mm. long by 12 mm. wide, ellipsoidal in side view, rounded pentagonal in top view, with flat summit, and periphery above mid-height. Stem and basais destroyed. Radials five, elongate hexagonal in side view, reaching adorally to periphery with narrow, shallow sinus 10 mm. long by 1.5 mm. wide. Deltoids overlap radials. The angle <strong>of</strong> the radial limbs at the radiodeltoid suture, with center at interradial suture is 85 degrees. Deltoids four, large, broadly rhombic, reaching below periphery, each 8 mm. long by 5.5 mm. wide, with one large triangular spiracle in the middle <strong>of</strong> the depressed adorai tip. On the anal side the triangular anispiracle is located between a pentagonal superdeltoid and a pentagonal hypodeltoid, with two hidden cryptodeltoids. Thus, five openings ocur around the oral aperture, consisting <strong>of</strong> four spiracles and an anispiracle. There is one hydrospire fold on each side <strong>of</strong> an ambulacrum, terminating admedially in a hydrospire plate. Ambulacra five, linear, raised, each 16 mm. long by 1.5 mm. wide, with lancet exposed along the middle onethird <strong>of</strong> its width almost to the aboral end, and 26 side plates in a space <strong>of</strong> 10 mm. along an ambulacrum. There are two pores to each side plate along the deltoid and radial margins. The surfaces <strong>of</strong> the calyx plates are almost smooth, with fine growth striae subparallel to plate margins, and granular raised ridges immediately aboral to each spiracle and anispiracle. Occurrence.—Lower Carboniferous, upper part <strong>of</strong> Clitheroe Limestone (C 2) <strong>of</strong> Salt Hill Knoll, Clitheroe, Lancashire, England (Beaver collection), and Carboniferous limestone, Yorkshire, England (deKoninck collection). Types.—Plesiotypes, 245, 11 specimens, deKoninck collection, old numbers, 2,324 and 467, Harvard Museum <strong>of</strong> Comparative Zoology, Cambridge, Mass.; one unnumbered specimen, Beaver collection, sent by DR. JOYSEY from Cambridge, England, Humble Oil & Refining Co., Houston, Texas. The above description is based on the specimen in the Beaver collection. Genus PENTREMITES Say, 1820 Type-species, by subsequent designation (ETHERIDGE & CARPENTER, 1886).—encrina Godonii DEFRANCE, 1819. Generic diagnosis.—Spiraculate blastoids with five spiracles or four spiracles and an anispiracle, with the anispiracle excavated in one anal deltoid plate, ?two, three to seven or more hydrospire folds on each side <strong>of</strong> an ambulacrum, oral and anal areas covered by many imbricate plates, one pore between side plates along deltoid and radial margins, lancet almost completely exposed, ambulacra petaloid, radials overlap deltoids, and shape <strong>of</strong> calyx in side view rounded obconical or club-shaped. Mississippian -Pennsylvanian, Alabama, Tennessee, Kentucky, Indiana, Illinois, Missouri, Iowa, Oklahoma, Arkansas, Mississippi, Montana, Alberta, ?Alaska. Remarks.—The genus Pentremites was probably derived from Devon oblastus by fusion <strong>of</strong> the anal deltoid plates into one, and continued downward migration <strong>of</strong> the deltoid plates, and outward migration <strong>of</strong> the lancet plates. A detailed description <strong>of</strong> the neotype (new holotype) <strong>of</strong> P. godoni is reserved for another paper to appear in the Journal <strong>of</strong> Paleontology. EXPLANATION FIGURE PAGE 1-6. Elaeacrinus venustus (MILLER & GURLEY). 1 3. Syntype, 6,114, Univ. Chicago; Devonian, Columbus, Ohio; oral, "D" ambulacral, aboral views <strong>of</strong> figured type (Miller & Gurley, 1894, pl. 8, fig. 26-30) (all X4.1).-4-6. Syntype, 1,317, Univ. Cincinnati; Devonian, Columbus, OF PLATE 28 Ohio; oral, "D" ambulacral, aboral views (all X3.7) 69 7-10. Elaeacrinus verneudi ROEMER, plesiotype, 9,956, Gurley coll., Univ. Chicago; Devonian, Jeffersonville Limestone, Jeffersonville, Ind., 7-9, oral, aboral, "D" ambulacral views ( X1.7); 10, enlarged oral view <strong>of</strong> summit ( X4.3) 68