﻿Mill CHERT 



SILURIC AND DEVONIC CYSTIDEA -53 



aboi 1 95 mm., with the root end about 7 mm. high. Firsl i i seg- 

 ments beneath the theca thinnest, with angulated peripheries, fol- 

 lowed by alxmt 65 segments of marly equal size and rounded edges. 



This species is readily distinguished from the associated S. multi- 

 fasciatus by the globular form of the theca, the non-excavated base, 

 the smaller number of ambulacral branches, thus causing the surface 

 to appear smoother; finally, by the higher position of plate 12, which 

 does not attain the basal row as in that species. 



formation and locality. — Not rare in the cystid beds of the Manlius 

 in the quarries near Keyser, West Virginia. 



A specimen with the entire column was found by Mr. Gordon in 

 the bryozoa beds of the Manlius, at Devil's Backbone, near Cumber- 

 land. Maryland. 



Cat. numbers 35.053, 35,077, U. S. N. M. 



S. GLOBULARIS OVALIS n. var. 

 (Plate XXXVIII, figure 6) 



Associated with 5\ globularis are specimens that attract attention 

 on account of their more elongate and regularly ovate thecae. These 

 specimens never attain the size of that species, however, and they 

 commonly retain a portion of the column, a feature much more rare 

 than in the variety oralis. In addition to the smaller size, and the 

 rounded-ovate outline of the theca, the variety is further distinguish- 

 able in always having the 4 ambulacra less bifurcate. The number 

 of branchlets varies between 5 and 10, the average being 6 or 7. In 

 13 specimens, the ambulacra divided as follows: 1 with 5 branchlets, 

 4 with 6, 4 with 7, 2 with 8, 1 with 9, and 1 with 10. In S. globularis 

 the average number of branchlets is between 10 and 12. 



Cat. number 35,054, U. S. N. M. 



Class CRINOIDEA 

 ? Order MONOCYCLIC A CAM ER AT A 

 Family Camarocrinidje Barrande (emend.) 

 Camarocrinns Hall 

 Camarocrinus Hall, Twenty-eighth Rep. N. Y. State Mus. Nat. Hist. 

 Mus. ed., 1879, pp. 205-6; extract, 4 , with additions, 1880, pp. 3-5. 

 — Zittel, Grundzrige der PaLxontologie, 1895, p. 154.— Zittel and 

 Eastman, Text-book of Palaeontology, 1896, p. 183.— Haeckel, Die 

 Amphorideen und Cystoideen, Leipzig, 1896, pp. 168-169.— Barrande 

 and Waagen, Syst. Sil. du Centre de la Boheme, vn, pt. 1, 1897, p. 1.— 

 Bather, Treatise on Zoology, in, Echinoderma, 1900, pp. 77, 136, 161. 



