ARC— ASP.] 



ECHINODERMA TA. 



225 



Fig. 249. — Archseoci- 

 daris agassizi, show- 

 ing spines. 



ulation of a primary spine, and the 

 whole surrounded by smaller tubercles 

 for the articulation of secondary spines; 

 mouth surrounded by numerous imbri- 

 cating plates ; jaws strong with mesial 

 suture ; primary spines large, variously 

 ornamented. Type A. urii. 

 aculeata, Shumard, 1858, Trans. St. Louis 

 Acad. Sci., vol. 1, p. 223, Permian Gr. 

 agassizi, Hall, 1858, 

 Geo. Rep. Iowa, p. 

 698, Burlington Gr. 

 biangulata, Shumard, 

 1858, Trans. St. 

 Louis Acad. Sci., 

 vol. 1, p. 224, Coal 

 Meas. 

 cratis, White, 1876, 

 Geol. of Uinta 

 Mountains, p. 109, 

 and Cont. to Pal., 

 No. 6, p. 130, Lower 

 Aubrey Gr. 

 dininni, White, 1880, 

 Proc. U. S. Nat. 

 Mus., vol. 2, p. 260, 

 and Cont. to Pal., 

 No. 6, p. 131, Up. Coal Meas. 

 edsrarensis, Worthen & Miller, 1883, Geo. 

 Sur. III., vol. 7, p. 337, Up. Coal 

 Meas. 

 gracilis, Newberry, 1861, Ives Col. Ex. 



Ex., p. 117, Up. Carb. 

 illinoisensis, Worthen & Miller, 1883, Geo. 



Sur. 111., vol. 7, p. 338, St. Louis Gr. 

 keokuk, Hall, 1858, Geo. Rep. Iowa, p. 



699, Keokuk Gr. 



longispina, Newberry, 1861, Ives Col. Ex. 



Ex., p. 116, Up. Carb. 

 mega8tylus, Shumard, 1858, Trans. St. 



Louis Acad. Sci., vol. 1, p. 225, Up. Coal 



Meas. 

 mucronata, Meek & Worthen, 1860, Proc. 



Acad. Nat. Sci. Phil., p. 395, and Geo. 



Sur. 111., vol. 2, p. 295, Kaskaskia Gr. 

 newberryi, Hambach, 1884, Trans. St. 



Louis Acad. Sci., vol. 4, p. 548, Kas- 

 kaskia Gr. 

 norwoodi, Hall, 1858, Geo. Rep. Iowa, p. 



701, Kaskaskia Gr. 

 ornata, Newberry, 1861, Ives Col. Ex. Ex., 



p. 116, Up. Carb. 

 shumardana, Hall, 1858, Geo. Rep. Iowa, 



p. 699, Warsaw Gr. 

 spinoclavata. Worthen & Miller, 1883, 



Geo. Sur. 111., vol. 7, p. 337, Coal Meas. 

 triplex, White, 1882, Rep. Carb. Invert. 



Foss. New Mex., p. xxii, Coal Meas. 

 triserrata, Meek, 1872, Pal. E. Neb., p. 



151, Up. Coal Meas. 

 trudifera, White, 1874, Rep. Invert. Foss., 



p. 17, and Geo. Sur. W. 100th Mer., vol. 



4, p. 104, Carb. 

 verneuiliana, Swallow, 1858, Trans. St. 



Louis Acad. Sci. This name was pre- 



occupid by King. The species is A. 



aculeata. 

 wortheni, Hall, 1858, Geo. Rep. Iowa, p. 



700, St. Louis Gr. 



Arch.eocrinus, Wachsmuth & Springer, 

 1881, Proc. Acad. Nat. Sci. and Rev. 

 Palseocrinoidea, p. 189. [Ety. urchaios, 

 ancient; krinon, lily.] Basals 5; sub- 

 radials 5 ; primary radials 3x5; second- 

 ary radials 3 or 4 x 10 ; median line of 

 radial plates keeled as in Glyptocrinus ; 

 interradial areas wide ; arms composed 

 of a double series of plates ; column 

 round. Type A. lacunosus. 



desideratus, Billings, 1885, Trans. Ottawa 

 Field Nat. Club, p. 248, Trenton Gr. 



lacunosus, Billings, 1857, (Glyptocrinus 

 lacunosus,) Rep. of Prog. Geo. Sur. 

 Can., p. 261, and Org. Rem., Decade 4, p. 

 61, Trenton Gr. 



marginatus, Billings, 1857, (Glyptocrinus 

 marginatus,) Rep. of Prog. Geo. Sur. 

 Can., p. 260, and Org. Rem., Decade 4, 

 p. 59, Trenton Gr. 



microbasalis, Billings, 1857, (Rhodocrinus 

 microbasalis,) Rep. of Progr. Geo. Sur. 

 Can., p. 264, and Org. Rem., Decade 4, 

 p. 63, Trenton Gr. 



pyriformis, Billings, 1857, (Rhodocrinus 

 pyriformis,) Rep. of Prog. Geo. Sur. 

 Can., p. 262, and Org. Rem., Decade 4, 

 p. 61, Trenton Gr. 



Pig. 2-50.— Archseocrinus sculptus. 



sculptus, S. A. Miller, 1882, Jour. Cin. 



Soc. Nat. Hist., vol. 5, p. 83 and 117, 



Trenton Gr. 



Arthracantha, Williams, 1883, Proc. Am. 



Phil. Soc, p. 84. [Ety. arthron, joint ; 



akantha, spine.] Calyx bowl-shaped; 

 plates of body and arms covered with 

 spine-bearing tubercles ; basals 3 ; 

 primary radials 3x5, the lower one 

 large, the others small; an azygous in- 

 terradial as large as the primary radials 

 rests upon the basals, and is followed 

 by numerous small plates; regular in- 

 terradials small; arms 10, bearing pin- 

 nules ; column round. Type A. 

 ithacensis. 



carpenteri, Hinde, 1885, (Hystricrinus 

 carpenteri,) Ann. and Mag. Nat. Hist., 

 p. 162, Ham. Gr. Probably a syn. for 

 A. punctobrachiata. 



ithacensis, Williams, 1883, Proc. Am. 

 Phil. Soc, p. 83, Ham. Gr. 



punctobrachiata, Williams, 1883, Proc. 

 Am. Phil. Soc, p. 83, Ham. Gr. 

 Aspidocrinus, Hall, 1859. Pal. N. Y., vol. 3, 

 p. 122. [Ety. aspis,- shield ; krinon, 

 lily.] Calyx broadly circular, de- 

 pressed, hemispheric or scutelliform ; 

 upper margin plain or plicate ex- 

 teriorly ; articulating edges irregular ; 

 point for attachment of column small. 

 Type A. scutelliformis. 



