20 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



The following is the original description by Troost: 



It differs from 0. [Nucleocrinus] vemeuili in being globular, and having no pro- 

 jecting ridges, nor are any transverse stria on the fields between the ambulacra, 

 perceptible. 



Bedford County, Tennessee. 



Observations. — Doctor Troost's specimen is about three-fourths 

 the height of Nucleocrinus vemeuili and the interambulacral areas 

 are wider than those of any of the specimens of the latter species 

 with winch it has been compared. The difference in height can 

 hardly be due to compression, since the specimen has not the diame- 

 ter necessary to account for such a decrease in height. The globular 

 form, together with the wide ambulacra! areas lead to the retention 

 of Troost's species, at least until forms are found connecting it more 

 closely with Nucleocrinus vemeuili. 



The method of preservation of Nucleocrinus globosus is the same as 

 that of specimens of N. vemeuili from the Falls of the Ohio, and 

 they may be from the same locality, since Doctor Troost's records 

 of localities were found, in a few instances, to be erroneous. 



Cat. No. 33076, U.S.N.M. 



Family OKBITREMITID.E Bather. 

 Genus ORBITREMITES Austin. 



Orbitrcmites J. E. Gray, Synops. Contents Brit. Mus., 42nd ed., 1S40, p. G3(nomen 

 nudum). — T. Austin and T. Austin, Jr., Ann. and Mag. Nat. Hist. (1), X, 

 1842, p. 111.— Bather, List Blastoidea Brit. Mus. (Nat. Hist.), 1S99, p. 23; 

 A Treatise on Zool., Ill, The Echinoderma, 1900, p. 90. 



Grariatocrinus Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 1S50, p. G2 

 (nomcn nudum); Amer. Journ. Sci., 2d ed., VIII, 1849, p. 420. — Hall, 15th 

 Rep. New York State Cab. Nat. Hist., 1862, p. 146.— Shumard, Trans. 

 Acad. Sci. St. Louis, II, No. 2, 1866, p. 37").— Meek and Worthen, Rep. 

 Geol. Surv. Illinois, II, 1866, p. 274.— Zittel, Handb. Pal., I, Pt, 3, L879, 

 p. 434. — Etheridge and Carpenter (in part), Ann. and Mag. Nat. Hist., 

 IX., L882, p. 236; Cat. Blastoidea, 1886, p. 238.— Miller, North Amer. 

 Geol. and Pal., 1SS9, p. 250. 



Elaeacrinus Shumard (in part), Trans. Acad. Sci. St. Louis, II, No. 1, 1863, 

 p. 112. 



Cidaroblastus Hambach, Trans. Acad. Sci. St. Louis, XIII, 1903, pp. 24-32, 45. 



The original description by Troost is as follows: 



This genus in some of its characters approaches Olivanites and Pentremites, having, 

 like these genera, five double rows of pores. It is distinguished from the Pentremites 

 by the absence of a column" and by being destitute of the five characteristic aper- 

 tures upon which the generic name of Pentremites is founded; and from the Olivanites 

 [by the absence] of the division of the fields between the ambulacra which in the 

 Granatocrinites is composed of three plates, and which is not the case with the 

 Olivanites. 



" Hambach says that a surface for the articulation of a column is present on Troost's 

 type.— E. W. 



