242 



ECHINODERMA TA. 



[ECT. ERE. 



ECTENOCRINUS, n. gen. [Ety. ekleino, I 

 stretch out; krinon, lily.] General 

 form very elongate ; 

 calyx small, subcylindri- 

 cal, moderately expand- 

 ing; basals 5, unequal; 

 radials irregular, four 

 plates in three series, 

 before the bifurcation of 

 the free arms, and three 

 in each of the other two 

 series ; arms 10, long ; 

 pinnules strong; azygous 

 plates 3, following each 

 other, but not in a direct 

 line; vault unknown; 

 column very long, round, 

 tripartite, and attaching 

 by an expanded base. 

 Type E. simplex. This 

 genus is founded upon 

 Heterocrinus simplex, 

 Hall, as the type, be- 

 cause the genus Hetero- 

 criuus was founded upon 

 H. heterodactylus, as 

 rhich is quite widely re- 



FIG. 295. 

 Ectenocriuus 



graixlis. 



the type, 



moved from H. simplex. 



canadensis, Bill- 

 ings, 1859, 

 (Heterociinus 

 can ad en sis,) 

 Can. Org. 

 Reno., Decade 

 4, p. 48, Tren- 

 ton Gr. 



grandis, Meek, 

 1873, (Hetero- 

 crinus sim- 

 plex var. gran- 

 dit>,) Pal. Ohio, 

 vol. 1, pi. 1, Fm.296. Ectenocrinus 

 fig. 7, Hud. simplex. Diagram. 

 Riv. Gr. 



simplex, Hall, 1847, (Heterocrinus sim- 

 plex,) Pal. N. Y., vol. 1, p. 280, Trenton 

 and Hud. Riv. Gr. 



EDKIOASTER, Billings, 1858, Can. Org. Rem., 

 Decade 3, p. 82. [Ety. edriun, seat ; 

 asttr, star.] A substitute for Cyclasrer, 

 proposed in 1857, the latter name hav- 

 ing been preoccupied. Body sess-ile, 

 discoid; plates numerous, irregular, 

 polygonal; ambulacral grooves 5, 

 tapering, composed of two series of 

 oblong ossicles; with four rows of 

 ambulacral pores in each ; mouth 

 large, termed of five oral and five in- 

 ternal ossicles. Type E. bigsbyi. 



bigsbyi, Billings, 1857,' (Cyclaster bigsbyi,) 

 Rep. of Progr. Geo. Sur. Can., p. 293, 

 and Can. Org. Rem., Dtcade 3, p. 82, 

 Trenton Gr. 



EDHIOCIUXUH, Hull, 1859, Pal. N. Y., vol. 3, 

 p. 119. [Ety. edrion, seat; krinun, lily.] 

 Body obconic; base solid, without 

 column ; mdials 5, resting, in depres- 

 sions, in the base ; azygous plates 2, 

 on*e large, resting in a basal depres- 



sion, the other smaller and succeeding 

 the first; arms composed of trans- 

 versely linear plates and bifurcating. 

 Tvpe E. pocilliformis. 



pocilliformis, Hall, 1859, Pal. N. Y., vol. 

 3, p. 121, Low. Hel.l. Gr. 



pyriformis, Hall, 1862, loth Rep. N. Y. 

 St. Mus. Nat. Hist., p. 88. Up. Held.Gr. 



sacculus, Hall, 1859, Pal. N. Y., vol. 3, p. 



143, Oriskany sandstone. 

 Else-icrinus, Roemer, 1852, syn. for Nucleo- 

 crinus. 



kirkivoodensis, see Nucleocrinus kirkwood- 

 ensis. 



verneuili, see Nucleocrinus verneuili. 

 ELEUTIIEROCRINUS, Shumard & Yandell, 

 1856, Proc. Acad. Nat. Sci. Phil., vol. 8, 

 p. 73. [Ety. eltutheros, free; krinon, 

 lily.] Calyx subelliptical, resembling 

 Nucleocrinus in form but depressed on 

 the azygous side ; trunca el at the 

 summit and bulged on one side ; sub- 

 triangular at the base and prolonged 

 on one of its sides ; basals 3, one small, 

 two irregular and much elongated ; 

 radials 1 x5, four-forked, occupying 

 nearly the length of the calyx, one 

 short and not forked ; inte'rradials 

 1x5; pseudambulacral areas 5, four 

 linear, extending nearly the entire 

 length of the calyx, one short, subtri- 

 angular, situated on the summit plane ; 

 apertures 8 (?). Type E. cassedayi. 



cassedayi, Shumard & Yandell, 1856, 

 Proc. Acad. Nat. Sci. Piiil., vol. 8, p. 

 74, Up. Held. Gr. 



whitfieldi, Hall, 1862, 15th Rep. N. Y, St. 

 Mus. Nat. Hist., A pp. C, p. 123, Ham. Gr. 

 EOCIDARIS, Desor, 1858, Synopsis de.s Echi- 

 nides Fossiles. [Ety. eos, dawn ; cilaris, 

 turban.] Plates hexagonal ; one large 

 tubercle on each plate, smooth at the 

 base and perforated at the summit; 

 distinguished from Archseocidaris by 

 the absence of a second ring. Type E. 



drydenensis, Vanuxem, 1842, (Echinus 



drydenensis,) Geo. Rep. 3d Dist. N. 



Y.", p. 184, and 20th Rep. N. Y. St. 



Mus. Nat. Hist., p. 343, Chemung Gr. 

 hallanns, Geinitz, 1866, Garb, und Dyas. 



in Neb., p. 61, and Pal. E. Neb., p. 



152, Up. Coal Meas. 



sqnamosus, see Lepidocidaris squamosus. 

 EOCYSTITKS, Billings, 1868, Acad. Geol., p. 



643. [Ety. eos, dawn; kustis, bladder.] 



Plates numerous, varying in size, form, 



and ornamentation, usually radiately 



sculptured. Type E. primsevus. 

 longidactvlus, Walcott, 1886, 



Bull. U. S. Geo. Sur., No. 



30, p. 94, Upper Tnconic. 

 primaevus, Billings, 1868, Acad. 



Geol. p. 643, Up. Taconic, 



St. John's Gr. 

 ERKTMOCRIXCS, Lyon & Casseday, 



1859, Am. Jour. Sci. and 



Arts, vol. 28. p. 241. [Ety. 



eretmoK, oar; krinon, lily.] Body bitur- 



