TROOST 's CRICOIDS OF TENNESSEE — E. WOOD. 



81 



Formation and locality. — Keokuk horizon of the Tullahoma forma- 

 tion. Indian Creek, Montgomery County, Indiana, White's Creek 

 Springs, Davidson County, Tennessee. 



Cat. No. 39900, U.S.N.M. 



ACTINOCRINUS PERNODOSUS Hall. 



Actinocrinus pernodosus Hall, Geol. Rep. Iowa, I, Pt. 2, 1858, p. 608, pi. xv, 

 figs. 3a, b; pi. xvi, fig. 7. — Shumard, Trans. Acad. Sci. St. Louis, II, No. 2, 

 1866, p. 346 (catalogue name). — Wachsmuth and Springer, Rev. Pal- 

 seocrinoidea, II, 1881, p. 145 (catalogue name). — Miller, North Amer. 

 Geol. and Pal., 1889, p. 219 (catalogue name). — Keyes, Missouri Geol. 

 Surv., IV, 1894, p. 190. — Wachsmuth and Springer, North Amer. Crinoidea 

 Camerata, 1897, p. 561, pi. lv, figs. 2a, b — Weller, Bull. No. 153, U. S. 

 Geol. Surv., p. 61 (catalogue name). 



Among some miscellaneous fragments in the Troost collection is a 

 specimen which apparently represents the lower part of the calyx of 

 this species. 



Formation and locality. — Keokuk horizon of the Tullahoma forma- 

 tion. White's Creek Springs, Tennessee (?). The specimen in Doctor 

 Troost' s collection bore no locality label, but as it is preserved in the 

 same manner as his material from White's Creek Springs it is probably 

 from that locality. Keokuk, Iowa; Nauvoo, Hamilton, and Warsaw, 

 Illinois; Way land, Clark County, Missouri. 



Cat. No. 39977, U.S.N.M. 



Subclass DICYCLICA Bather. 

 Order DICYCLICA INADUNATA Bather. 



Suborder CYATHOCRINOIDEA Bather. 



Family CYATHOCRINIDiE Bather. 

 Genus CYATHOCRINUS Miller. 



CYATHOCRINUS BRITTSI Miller and Gurley. 



Plate 15, figs. 2, 3. 



Cyathocrinites tennesseeae Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 1850 

 (nomen nudum); MSS., 1850. 



Cyathocrinus tennesseeus Wachsmuth and Springer, Rev. Palseocrinoidea, I, 

 1879, p. 149 (catalogue name). 



Cyathocrinus tennesseeae Miller, North Amer. Geol. and Pal., 1889, p. 237 (cata- 

 logue name). 



Cyathocrinus brittsi Miller and Gurley, Bull. No. 7, Illinois State Mus. Nat. 

 Hist., 1895, p. 70, pi. iv, figs. 35, 36. 



The following description is by Troost: 



This crinoid was at first mistaken for a species of Qiderocrinites Troost with which it 

 has some resemblance, but it differs from it by having only a single quadrilateral 

 interscapular whereas the Siderocrinites has five intercostals. 



It is basin-shape. — Its horizontally projecting scapulars [radials] give to its superior 

 part a pentagonal form. Its subpentagonal costals [basals] are so short that they 

 appear almost triangular. Its pelvis [base composed of five infrabasals] is small being 

 almost entirely taken up by the circular cicatrice of the column. 



It occurs in Decatur County, Tennessee. 



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