OHI. — OU.] 



ECHINODERMA TA. 



263 



for receiving the bases of the narrow, 

 elongtte ambulacra, and having pro- 

 jecting lips forming a quinquepod ; 

 deltoid plates 6, elongate, forming 

 three-fourths of the calyx; a narrow 

 intercalated plate, on the azygous side, 

 reaches from the aperture to the radial, 

 and divides the deltoid into two nar- 

 row curving plates; sinuses narrow, 

 extending the entire length of the 

 calyx ; ambulacra narrow ; lancet plates 

 long and very narrow ; side plates 

 numerous ; hydrospires pendent, two 

 tubes or elongated sacs on each side of 

 an ambulacrum ; spiracles in five pairs, 

 which notch the deltoid plates; mouth 

 large, covered normally with pla f .es; 

 azygous opening large. Types N. elegans 

 and N. verneuili. 

 angulari-*, Lyon, 1857, (Olivanites angu- 

 laris,) Geo. Sur. Ky., vol. 3, p. 492, 

 Ham. Gr. 

 canadens s, Montgomery, 1881, Can. Nat. 



and Geol. Vol. 10, p. 83, Ham. Gr. 

 conradi, Hall, 1862, 15th R p. N. Y. St. 

 Mus. Nat. Hist., App. 0., p. 121, Up. 

 H- Id. Gr. 

 elegans, Conrad, 1842, Jour. Acad. Nat. 



Sci. Phil., p. 280, Ham. Gr. 

 haUii, syn. for Nucleocrinus elegans. 

 kirkwoodensis, Shumard, 1863, (Eleacri- 

 nus kirkwoodenuis,) Trans. St. Louis 

 Acad. Sci., vol. 2, p. 113, St. Louis Gr. 

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

 Mus. Nat. Hist., App. C, p. 120, 

 Ham. Gr. 

 meloniformis, 

 Barris, 1883, 

 ( Eleacrinus 

 melon i - 

 formis,)Geo. 

 Sur. 111., vol. 

 7, p. 361, 

 Ham. Gr. 

 obovatus, Bar- 

 r i s , 1883, 

 ( Eleacrinus 

 obova t u s , ) 

 Geo. Sur. 

 III., vol. 7, p. 

 358, Ham. 

 Gr. 

 verneuili, Troost, 1841, (Pentremites ver- 

 neuili,) 6th Rep. on 

 the Geo. of Tenn., p. 

 14, and Geo. Sur. Ky., 

 vol. 3, p. 488, Up. 

 Held. Gr. 

 vera- uili var. pomvm, Eth- 

 eridge & Carpenter, is 

 simply a rounded form 

 very common among 

 other specimens, and 

 without varietal char- Fig. 370.— Nnoleo- 

 acters. crinus verneuili. 



Ohiocrinus, Wachsmuth & Springer, 1885, 

 Palaeocrinoidea. pt. 3, p. 208. [Ety. 

 proper name ; knnon, lily.] Plates of 

 calyx arranged as in Heterocnnus; 



9. — Nucleocrinus obo- 

 Cross section of hy- 



drospires, 2 di,i in. 



Fig. 371. 

 Ohiocrinus 



arms 10, bearing bifurcating pinnules ; 

 ventral tube large, having a spiral form 

 somewhat like the cast of a 

 Murchisonia, and covered 

 with hexagonal plates; 

 column pentagonal and pen- 

 tapartite. Type O. laxus. 

 compactus, Meek, 1873, (Hete- 

 rocrinu8Constrictusvar.com- 

 pactus,) Ohio Pal., vol. 1, pi. 

 11, Hud. Riv. Gr. 

 constrictus, Hall, 1866, ( He te- compuctus ' 

 rocrinus constrictus,) 24th Rep. N. Y. 



St. Mus. Nat. Hist, p. 



210, Hud. Riv. Gr. 

 laxus, Hall, 1866, (Hete- 



rocrinus laxus,) 24th 



Rep. N. Y. St. Mus. Nat. 



Hist, p. 211, Hud. 



Riv. Gr. 

 cehanus, Ulrich, 18 8 2, 



(Heterocrine cehanus,) 



Jour. Cin. Soc Nat. 



Hist, vol. 5, p. 175, 



Hud. Riv. Gr. 

 Fig. 372. Oligoporus, Meek & Wor- 

 coSSs. then, 1860, Proc. Acad. 



Nat. Sci. Phil., p. 474. 

 [Ety. oh'gos, few; poros, passage.] In 

 form like Melonites, but distinguished 

 by having only four rows of ambula- 

 cral plates, and four double rows of 

 pores in each ambulacral area. Type 

 O. danse. Desor used the name Oligo- 

 pores, in 1858, for a section of the 

 Cidsridae, and Prof. Meek said if desir- 

 able to change Oligoporus, for that 

 reason he would suggest Melonopsis in 

 its place, 

 coreyi, Meek & Worthen, 1870, Proc. 

 Acad. Nat Sci. Phil., p. 34, Keo- 

 kuk Gr. 



Fig. 373.— Oligoporus dance ; 2 dlam. 



danae, Meek & Worthen, 1860, (Melon- 

 ites danse,) Proc. Acad. Nat. Sci. Phil., 

 p. 397, and Geo. Sur. 111., vol. 2, p. 249, 

 Keokuk Gr. 



nohilis, Meek & Worthen, 1868, Proc. 

 Acad. Nat. Sci. Phil., p. 358, and 

 Geo. Sur. 111., vol. 5, p. 476, Burling- 

 ton Gr. 



parvus, Hambach, 1884, Trans. St. Louis 

 Acad. Sci., vol. 4, p. 548, Keokuk Gr. 

 Olivanites, syn. for Nucleocrinus. 



angularis, see Nucleocrinus angularis. 



verneuili, see Nucleocrinus verneuili. 



