234 The American Geologist. October, 1903. 
Column tapering- rapidly for a very short distance and then 
hardly at all throughout its length. Total length about 95 mm., 
with the root end about 7 mm. high. First 11 segments be- 
neath the theca thinnest with angulated peripheries followed 
by about 65 segments of nearly equal size and rounded edges. 
This species is readily distinguished from the associated 5\ 
multifasciatus by the globular form of the theca, the non-ex- 
cavate base, smaller number of ambulacral branches causing 
the surface of the theca to appear smoother; and 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 speci- 
men with the entire column was found by Mr. Gordon in the 
Bryozoa beds at Devil's Backbone, near Cumberlan i, Maryland. 
Cat. number 35,953, 35,077, U. S. N. M. 
Coelocystis n. gen. 
Hemic osmites Hall (non von Buch), Twentieth Rep. N. Y. 
State Cab. Nat. Hist., rev. ed. 1868 [1870]. p. 359. 
Sphaerocystites Jaekel (partim, non Hall), Stammesges- 
chichte der Pelmatozoen, I, Berlin, 1899, p. 289, fig. 63; also 
P- 307- 
Until recently Sphaerocystites seems to have been based up- 
on a single example, the holotype of S. multifasciatus. As the 
specimen did not permit Hall to decipher the thecal structure, 
Jaekel gave the plate formula for Sphaerocystites, but based 
it upon S. dolomiticus J aekel= Hemic osmites subglobosus Hall. 
The present work gives the plate formula for Sphaerocystites 
based upon the original genotype 6". multifasciatus and the 
study has shown that Jaekel's type is of quite another and more 
primitive genus. For this reason the Niagaran form is dis- 
tinguished under the generic name Coelocystis, having refer- 
ence to the deeply invaginated base of the theca. 
Hemic osmites is quite a different genus as the plate for- 
mula is 4 + 6 + 9 + 9, anal area 7, 8 and 13 (see Bather, Treat- 
ise on Zoology, Pt. Ill, Echinoderma, London, 1900, p. 68, 
%• 3)- 
Definition. — Callocystinae ? having a depressed globular 
theca with a deeply invaginated base, and composed of 24 
plates arranged as follows : 
