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086 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
flattened above; they are biserial, long, and incurving, — their tips some- 
times descending to the top of the calyx,—and are composed at their bases 
of short transverse pieces, which gradually increase in length and width 
upward. Interradials not numerous, there being from one to three plates 
at the regular sides, and from four to seven at the anal side including the 
anals. Ventral disk distinctly asymmetrical, somewhat bulging and higher 
toward the anterior side, rather flattened posteriorly. Posterior oral con- 
spicuous, large, and central in position; the anal tube excentric and often 
curving outward. Column round; the axial canal small and pentangular. 
Distribution. — Restricted to the Burlington limestone and Keokuk group, 
and, so far as known, confined to America. 
Type of the genus: Hretmocrinus magnificus Lyon and Cass. 
Lemarks. — Meek and Worthen treated Eretmocrinus as a subgenus of 
Batocrinus, and added several forms which do not belong to it. It differs 
from Latocrinus in the broad, truncated, and projecting basals, the long, paddle- 
shaped, and incurving arms, their arrangement, the asymmetry of the ventral 
disk, and in the excentric position of the anal tube, —all of which are good 
distinctive characters. 
Eretmocrinus magnificus Lyon and Cass. 
Plate XXXVI. Fig. 3. 
1859. Jivon and Cassmpay; Amer. Journ. Sci., Vol. XXVIII., p. 241. 
1881. W. and Sp.; Revision Paleoer., Part II., p. 173. 
(Not Hretmocrinus magnificus Quenstept ; Handb. der Palewont. (Auflage 3), Plate 77, Fig. 11= 
Batocrinus grandis). 
Syn. Lretmocrinus lyonanus 8. A. Minter; Adv. Sheets 17th Geol. Rep. Indiana, 1891, p. 59, Plate 
10, Figs. 3 and 4. 
Calyx higher than wide, biturbinate ; the dorsal cup frequently shorter 
than the ventral disk; broadly truncate at the base; the sides concave, 
spreading abruptly near the arm bases.. The radials and brachials in well- 
marked specimens are keel-shaped, with a prominence or node in the centre 
of each plate, in others they are simply convex ; the interbrachial plates, in 
most of the specimens, are perfectly flat. 
Base short, extended into a broad rim, which projects considerably 
beyond the radials; it has a shallow depression at the bottom, and a some- 
what deeper one for the reception of the column, which occupies less than 
half the diameter of the lower face. Radials more than twice as wide as 
long. First costals quadrangular, about half the size of the radials; the 
