TRE. — XEN.] 



ECHINODERMA TA. 



287 



trading sides of the ambulacral plates, 

 and the concave sides of the curving 

 adambulacrals ; four plates border on 

 each pore ; orals 10. Type T. dif- 

 ficilis. 



difficilis, Worthen & Miller, 1883, Geo. 

 Sur. 111., vol. 7, p. 330, Kaskas- 

 kia Gr. 

 Trematocrinus, syn for Goniasteroidocri- 

 nus. 



fiscellw, see Goniasteroidocrinus fiscel- 

 lus. 



papillatus, see G. papillatus. 



reticulalun, see G. reticulatus. 



robustns, see G. robustus. 



spinigrrus, see G. spinigerus. 



tuberculatum, see G. tuberculatum. 



typus, see G. typus. 

 Triucrinus, Ringueberg, 1887, Proc. Acad. 

 Nat. Sci. Phil., p. 144. The name was 

 preoccupied ; beside it is probably a 

 syn. for Pisocrinus. 



globosus, see Pisocrinus globosus. 



pyriformi*, see Pisocrinus pyriformis. 

 Triccslocrinus. Meek & Worthen, 1868, 

 Proc. Acad. Nat. Sci. Phil., p. 356, and 

 Geo. Sur. 111., vol. 5, p. 507. [Ety. treu, 

 three; koilos, hollow; krinon, lily.] 

 Calyx subpyramidal, or subfusiform ; 

 base short, trihedral, and excavated 

 along the interbasal sutures; summit 

 contracted ; radials long and narrow ; 

 deltoids small ; ambulacra narrow, 

 deeply situated in the sinuses; hydro- 

 spires small, three (?) on a side ; 

 spiracles and mouth small; anus 

 large ; column circular. Type T. wood- 

 man i. 



meekanus, Etheridge* & Carpenter, 1886, 

 Catal. of Blastoidea, p. 208, War- 

 saw Gr. 



obliquatus, Roemer, 1851, (Pentatrema- 

 tites obliquatus,) Arehiv f. Naturgesch., 

 Jahrg. xvii, p. 367, St. Louis Gr. 



varsouviensis, Worthen, 1875, Geo. Sur. 

 111., vol. 6, p. 521, St. Louis Gr. 



woodmani, Meek & Worthen, 1868, (Pen- 

 tremites, Troostocrinus) Triccelocri- 

 nus woodmani,) Proc. Acad. Nat. Sci. 

 Phil., p. 356, and Geo. Sur. 111., vol. 5, 

 p. 506, Warsaw Gr. 

 Troostocrinus, Shumard, 1865, Trans. St. 

 Louis Acad. Sci., vol. 2, p. 384. [Ety. 

 proper name ; krinon, lily.] Dis- 

 tinguished from Pentremites by the 

 slender, subfusiform shape, linear am- 

 bulacra, lancet plates concealed, tri- 

 angular base, and simple summit struc- 

 ture ; spiracles at the sides of the prox- 

 imal side plates; hydrospiral canals 

 open into linear spiracular apertures. 

 Type T. reinwardti. 



bipyramidalis, Hall, 1858, (Pentremites 

 bipyramidalis,) Geo. Sur. Iowa, p. 607, 

 Keokuk Gr. 



grosvenori, Shumard, 1858, (Pentremites 

 grosvenori,) Trans. St. Louis Acad. Sci., 

 vol. 1, p. 240, Warsaw Gr. 



lineatus, Shumard, 1858, (Pentremites 

 lineatus,) Trans. St. Louis Acad. Sci., 

 vol. 1, p. 241, Bur- 

 lington Gr. This is made 

 the type of the genus 

 MetablastusbyEtheridge /f 

 & Carpenter, to which i? . r , 

 they also refer T. wor- \V V 

 theni and Triccelocrinus V 



Fig. 443. 



Troostocrinus 



wortlieni. 



varsouviensis. 



reinwardti, Troost, 1835, 

 ( Pentremites reinwardti, ) 

 Trans. Geo. Soc Pa., vol. 

 1, p. 224, Niagara Gr. 



subcylindricus, Hall A: 

 Whitfield, 1875, (Pentre- 

 mites subcylindricus,) 

 Ohio Pal., vol. 2, p. 129, 

 Niagara Gr. 



subtruncatus, Hall, 1858, (Pentremites 

 subtruncatus,) Geo. Sur. Iowa, p. 485, 

 Ham. Gr. 



wortheni, Hall, 1858, (Pentremites wor- 

 theni,) Geo. Sur. Iowa, p. 606, Keo- 

 kuk Gr. 

 Vasocrinus, Lyon, 1857, Geo. Sur. Ky.,vol. 

 3, p. 485. [Ety. vas, vessel ; krinon, lily.] 

 Calyx low, vase-shaped ; basals 5; sub- 

 radials, 5 ; primary radials, 1x5; sec- 

 ondary radials 2x5; arms, 10 or more ; 

 azygous interradials 2 or more, first 

 one large; ventral sac. Type V. valens. 



lyoni, Hall, 1861, (Cyathocrinus lyoni,) 

 Desc. New Crin., p. 3, and Bost. Jour. 

 Nat. Hist., vol. 7, p. 298, Keokuk Gr. 

 .macropleurus, Hall, 1861, (Cyathocrinus 

 macropleurus,) Desc. New Crin., p. 5, 

 and Bost. Jour. Nat. Hist., vol. 7, p. 

 295, Burlington Gr. 



sculptus, Lyon, 1857, Geo. Sur. Ky., vol. 

 3, p. 486, Ham. Gr. 



valens, Lyon, 1857, Geo. Sur. Ky., vol. 3, 



p. 485, Ham. Gr. 



Xknocrinus, S. A. Miller, 1881, Jour. Cin. 



Soc. Nat. Hist., vol. 4, p. 71 and 176. 



[Ety. xenos, strange ; krinon, lily.] Ba- 



FlG. 444.— Xenocrinua penicillus. Azygous and 

 opposite side views and end of column. 



sals 4; primary radials 3x5; secondary 

 radials 4 to 6x10; interradial areas ex- 

 cavated and filled with numerous 



