384 THE -CRINOIDEA CAMERATA OF NORTH AMERICA. 
contact with one another and with the third distichals of the anterior ray. 
Arm bases not projecting; the arm openings equidistant. Arms eighteen, 
of medium length, rather stout, and gradually tapering; composed of rather 
long joints, which on the back are marked by a short rounded node. Pin- 
nules long. Ventral disk constructed of irregularly arranged nodose plates ; 
and similar plates form the walls of the anal tube, which is comparatively. 
strong and extends beyond the tips of the arms. Column tapering down- 
ward; the nodal joints with crenulated edges, and rather long; the inter- 
nodal joints quite narrow. 
Horizon aud Locality. — Keokuk group; Canton, Ind. 
Type in the collection of W. F. E. Gurley. 
ftemarks — Miller and Gurley describe this species as having four arms 
in the anterior ray. This must be exceptional, for seven of our specimens 
show distinctly but two arms in that ray, and eighteen to the specimen. 
Batocrinus laura (Hazz), 
Plate X XIX. Figs. 5a, b, ¢, d. 
1861. Actinoerinus laura — Hat; Prelim. Descr. New Crinoids, p. 15. 
1881. Batocrinus laura — W. and. SP. Revision Paleocr., Part IL, p. 167. ; 
1893. Batocrinus Dine = Nuch Mem. Amer. Mus. Nat. Hist., 1893, Vol. I., p. 17, Plate 1, Figs. 
Syn. ae rinus scyphus Mitten and Guriny, 1894; Geol. Surv. Illinois, Bull. 3, p. 23, Plate 5, 
Figs, 7, 8, 9. 
Calyx generally higher than wide, biturbinate. Dorsal cup gradually 
and uniformly expanding to the arm bases, its sides straight or slightly con- 
cave; the plates flat and smooth. Basals not projecting laterally, forming 
a short conical cup, rounded at the lower edge. Radials a little wider than 
long, their upper faces concave. First costals less than half the size of the 
radials, quadrangular, once and a half as wide as long, the lower face convex. 
The second smaller than the first, pentangular. Distichals 2 x 2, larger than 
the costals; the second larger than the first and twice as wide as long. The 
upper supports 2 x 2 palmars, of which the second is deeply excavated, and 
forms a horse-shoe-shaped facet for the reception of the arms. Arm Openings 
large, directed obliquely upwards; equidistant. Arms rather stout, of moder- 
ate length, rounded on the back. Interbrachials: 1, 2, and 1. The anal 
plate is followed by 3, 3, and 1 plate, arched by the palmars. Ventral disk 
lower than the dorsal cup, more or less conical; plates almost flat, except 
the posterior oral, which is somewhat convex. Anal tube central, of 
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