ACTINOCRINID 2. 5d7 
Actinocrinus lobatus Hatt (not WorrTHEn). 
Pilate LI. Figs. 1a, b, and Plate LIV. Fig. 3, and Plate LV. Figs. 1a, b. 
1860. Hann; Suppl. Geol. Rep. Iowa, p. 51. 
1881. W. and Sp.; Revision Paleocr., Part IL, p. 144. 
(2) Syn. Actinocrinus unicarinatus — Hau; Suppl. Geol. Rep. Iowa, 1860, p. 48. 
Larger than the preceding species; the lobes of the calyx more promi- 
nent; the interradial spaces deeper, and formed into pitlike depressions, 
which extend from the upper part of the first interbrachial to near the orals, 
reducing the width of the tegmen, with the brachial lobes removed, to the 
diameter of the dorsal cup at the radials. The dorsal cup rises moderately 
to the top of the first costals, above which the brachials take an almost hori- 
zontal position to the bases of the free arms. The lobes are narrower at the 
proximal than at the distal end, and at the back of the costals distinctly 
angular, their sides bending abruptly upward to meet the small interbrachial 
pieces interposed between them. In the lower part of the calyx, below the 
lobes, the plates are slightly tumid, having small central nodes, of which 
those upon the radials and costals are most prominent and transversely 
arranged. From the nodes, sets of parallel ridges proceed to the outer 
margins; but these, although quite distinct between basals and radials, are 
more or less obscure between the other plates. 
Basals proportionally large, forming a broad cup, twice as wide as high, 
notched at the sutures, and thickened around the lower margins. Radials 
very large, longer than wide, the upper face narrower than any of the 
others. Costals small, the two together less than one half the size of the 
radials; the first as wide aslong; the second as wide as the first, but 
shorter. Distichals nearly one third smaller than the upper costals, all 
axillary. They support at the outer side an arm, which is free from the 
second plate; at the inner side three palmars, which give off an arm to the 
inner side of the ray, and to the outer two post-palmars with two tree arms 
from the axillary. Arms forty (not twenty-five as described by Hall), moder- 
ately heavy, and branching in their free state. Interbrachials numerous ; 
the first as large as, or larger than, the first costals; the two of the second 
row one half smaller; there are other irregular plates overlying them, which 
meet the orals, and are in part interambulacral. Anal interradius the widest, 
and the plates still more numerous. The central part of the tegmen is almost 
flat, and raised but little above the top of the lateral extensions; its plates 
“i 
