270 



ECHINODERMA TA. 



[PLA. 



pyriformis, Ringueberg, (Triacrinus pyri- 



foriuis,) Proc. Acad. Nat. Sci. Phil., p. 



145, Clinton Gr. 

 PLATYCRINUS, Miller, 1821, Nat. Hist. Cri- 



noidt-a, p. 73. [ Ety. platys, flat ; krinon, 



lily.] Calyx bowl-shaped; nasals 3; 



primary radials 2x5; regular inter- 



radials 1x4; azygous interradials, 1 



large and 3 small ; dome elevated ; 



arms 10 to 35, bearing pinnules; 



column large and twisted. Type P. 



he vis. 

 aequalis, Hall, 1861, Desc. New. Crin., p. 



117, and Geo. Sur. 111., vol. 5, p. 456, 



Burlington Gr. 

 americanus, Owen & Shumard, 1850, 



Jour. Acad. Nat. Sci. Phil., 2d ser., vol. 



2, p. 89, Burlington Gr. 

 anndixoni, Troost. Not defined. 



FIG. 392. Platycrinus asper. Diagram. 



asper, Meek & Worthen, 1861, Proc. 



Acad. Na-. Sci. Phil., p. 129, and Geo. 



Sur. 111., vol. 3, p. 468, Burlington Gr. 

 bedf.-r.lensis, Hall & Whitfi^ld, 1875, 



Ohio Pal., vol. 2, p. 161, Erie S'mles. 

 bloom fieldenis, 8. A. Miller, 1880, Jour. 



Cin. Soc. Nat. Hist., vol. 2, p. 257, 



Keokuk Gr. 

 bonoensis, White, 1878, Proc. Acad. Nat. 



Sci. Phil., p. 30, and Cont. to Pal., No. 



6, p. 160, Keokuk Gr. 

 brevinodus, Hall, 1861, Desc. New Cri- 



noidea, p. 4, and Bost. Jour. Nat. 



Hist., vol. 7, p. 286, Keokuk Gr. 

 burlingtonensis, Owen & Shumard, 1850, 



Jour. Acad. Nat. Sci., 2d ser., vol. 2, p. 



60, Burlington Gr. 

 calyculus, Hall, 1861, Desc. New Crin., 



p. 16, Burlington Gr. 

 canaliculatus, Hall, 1858, Geo. Sur. Iowa, 



vol. 1. pt. 2, p. 539, Burlington Gr. 

 cavus, Hall, 1858, Geo. Sur. Iowa, p. 527, 



Burlington Gr. 

 clytis, Hall, 1861, D^sc. New Crin., p. 4, 



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



285, Burlington Gr. 

 contritus, Hall, 1863, 17th Rep. N. Y. St. 



Mus. Nat. Hist,, p. 54, and Ohio Pal., 



vol. 2, p. 166, Waverly Gr. 

 corporiculug, Ringueberg, 1886. Bull. Buf. 



Soc. Nat. Sci., vol. 5, p. 12, Niagara Gr. 



Not properly defined. 



corrngatus, Owen & Shumard, 1850, Jour. 

 Acad. Nat. Sci., vol. 2, p. 59, Burling- 

 ton Gr. 



depressus, Owen. Not defined. 



disooideus, Owen & Shumard, 1850, Jour. 

 Acad. Nat. Sci., 2d ser., vol. 2, p. 58, 

 Burlington Gr. 



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

 Mus. Nat. Hist., p. 119, Ham. Gr. 



elegans, Hall, 18'il, Desc. New Crin., p. 4, 

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

 p. 285, Burlington Gr. 



eminulus, Hall, 1861, Desc. New Crin., 

 p. 17, Burlington Gr. 



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

 Mus. Nat Hist., p. 119, Ham Gr. 



excavatus, Hall, 1861, Desc. New Crin., 

 p. 4, and Bost. Jour. Nat. Hist., vol. 7, 

 p. 286, Burlington Gr. 



exsertus, Hall, 1858, Geo. Sur. Iowa, p. 

 539, Burlington Gr. 



faberi, n. sp. Calyx bowl-shaped ; sub- 

 cylindrical above ; 

 attaching point for 

 column projecting 

 below ; base marked 

 by three keels, cor- 

 responding with the 

 sutures between 

 the basal plates, and 

 along which the FlG m _ Plat inus 

 sutures may be dis- faberi, x2. 

 tinguished ; radials 

 large, width a little greater than height ; 

 cicatrix for attachment of arms in the 

 center of the upper face of each radial, 

 and occupying about one-third of the 

 width of the plate ; surface marked by a 

 row of tubercles radiating on each 



Fio. 394 Platycrinus hemisphericus. Diagram. 



plate from the angle of union of basal 

 and radial plates, and also a few scat- 

 tering tubercles ; collected in Scott 

 County, West Va., in the St. Louis or 

 Kaskaskia Gr. 



