088 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Amphoracrinus divergens (Hatz). 
Plate LXIT. Figs. 5, 6a, b, Va, b, Sa, b, ¢, 9, 10. 
1860. <Actinocrinus divergens —HastL; Suppl. Geol. Rep. Iowa, p. 36. 
1881. <Amphoracrinus divergens —W. and Sv.; Revision Paleocr., Part IT., p. 155. 
1893, Amphoracrinus divergens — WHITFIELD ; Mem. Amer. Mus. Nat. Hist. N. York, Vol. I., p. 21, Plate 
2, Figs. 12, 18. 
Syn. Actinocrinus planobasilis Hatt; Suppl. Geol. Rep. Iowa, p. 19, figured in State Mus. Nat. 
Hist., Bull. 1., Plate 4, Figs. 10 and 11 Amphoracrinus planobasilis M. and W. (Geol. Rep. 
Illinois, Vol. V., p. 388). 
Syn. Actinocrinus quadrispinus Wurtz, 1862, Proceed. Boston Soc. Nat. Hist., Vol. IX., pe lis 
= Amphoracrinus quadrispinus W. and M.; 1873, Geol. Rep. Illinois, Vol. V., p. 388. 
Syn. Amphoracrinus divergens, var. multiramosus Mrux and Wortuen, Geol. Rep. Illinois, Vol. V., 
p. 388. 
— 
— = 
we 
Of rather large size. Crown in its natural condition, with all the arms 
preserved, as wide as, or wider than, high; the dorsal cup not visible from a 
side view. Calyx subpyramidal, distinctly lobed above the first costals, the 
interradial spaces deeply depressed between the free rays. Dorsal cup about 
one third the height of the ventral disk, saucer-shaped, truncated at the base. 
The rays from the second costals droop downward to the level of the bottom 
of the calyx, and then, at about the top of the first palmars, they bend ab- 
ruptly upward, and fold inward until the tips of the arms encircle the spi- 
niferous summit of the disk, exposing the spines. The entire surface of the 
calyx is covered with irregular granules or vermicular markings. 
Basals forming a slightly projecting, hexagonal disk, extending beyond 
the sides of the column ; the suture lines distinct, but not actually grooved ; 
axial canal small and sharply pentangular. Radials all hexagonal, owing to 
the straightness of the lower margins, and about once and a half as wide as | 
long. First costals almost horizontal; wider than the radials and nearly as 
long ; strongly inflected at the sides, and rounded exteriorly ; the upper face 
semicircular in outline, and directed slightly downward. The succeeding 
brachials constitute a part of the free extensions, and face more or less 
downward. The second costals, which are a little smaller than the first, 
are touched by the interbrachials only at their lower ends, the lateral 
upper parts of the plates resting against rigid ambulacral plates. Dis- 
tichals various in number, but as a rule the two posterior rays have one 
plate in each division, both axillary, and about as large as the second cos- 
tals. They support at each side a large quadrangular palmar, which is fol- 
lowed by a smaller cuneate one, and this by two rows of extremely short 
