510 ‘THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Agaricocrinus Coreyi (Lyon and Cass.). | 
Plate XX XIX, Figs. La, 6. 
1860. <Actinocrinus Coreyi— Lon and Cassepay; Amer. Journ. Sci. (sec. ser.), Vol. XXIX., p. 76. 
Syn. Agaricocrinus Springert — Wuttx, 1881; Eleventh Ann. Rep. Geol. and Nat. Hist. of Indiana, 
p- 368, Plate 40, Figs. 2, 3, 4. 
Of more than medium size. Calyx a little shorter than wide. Dorsal 
cup rather high for the genus, but somewhat lower than the ventral disk, 
saucer-shaped, truncated at the bottom, the sides convex. Plates elevated, 
sometimes a little angular, their surface smooth; suture lines distinctly 
erooved. 
Basals rather small; on a level with the radials, and forming a hexagon, 
which is almost completely hidden by the column. Radials stretched out 
horizontally, except the uppermost part which bends slightly upward; they 
are twice as large as both costals together, and one third wider than long ; 
their upper faces excavated and broader than the width of the plate at the 
bottom. Costals twice as wide as long, the first quadrangular, the second 
pentangular and frequently smaller than the first. Distichals two in the . 
calyx, very short; the first wedge-shaped; the second linear, followed by 
leaf-like cuneate pieces, which interlock from opposite sides. Arm facets 
lunate, unusually large and directed horizontally. Arms unknown, but ap- 
parently very stout. First interbrachial large, generally longer than wide, 
followed at the arm regions by two elongate pieces in the second row, 
and these by seven to eight interambulacral plates. First anal plate con- 
siderably longer than the radials, and forming with the two succeeding ones . 
a vertical row; second anal about one half the size of the first, the third very 
much smaller. Both these plates rest between two interbrachial pieces, of 
which those in the first row are very large, but those of the second quite 
small. Ventral disk pyramidal, pentangular in outline, the plates convex. 
Posterior oral conical, central in position, and three times as large as the 
four others. Interambulacral plates rather numerous, about one fourth the 
size of the smaller orals, The rays are surmounted by a large radial plate, 
placed close to the lower margin of the disk. Anus excentric, directed ob- 
liquely upward, and occupying the upper end of an elongate, distinctly 
rounded area, composed of small, smooth, irregular pieces. 
Horizon and Locahty. — Keokuk group; Hardin and Allen Cos., Ky., and 
Vermilion Co., Ind. 
Type in the Lyon collection. 
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