' 
ACROCRINID&. 807 
short joints, which near the calyx, at intervals of five to. six, are interrupted 
by longer and somewhat wider plates. 
Horizon and Locality. — Kaskaskia group; Grayson and Pulaski Cos., Ky. 
Type in the Yandell collection at Louisville. 
Remarks. — The fragmentary specimen from the same horizon of Pope 
Co., Ills., for which Hall proposed the name Acrocrinus urneeformis, is in all 
probability identical with this species. It has preserved only the basals and 
a few rings of the intercalated plates, which are not sufficient for accurate 
comparison. 
Acrocrinus Wortheni WacusmurTs. 
Plate LXXX. Figs. 10a, 6. 
1882. Wacusmuty; Bull. I. Illinois State Museum Nat. Hist. p. 41; and Geol. Rep. Illinois, Vol. VIL, 
p- 343 (with diagram). 
1885. W. and Se.; Revision Paleocr., Part IIL., p. 124. 
This species was described from a single specimen, of which only the 
dorsal cup is preserved. This, however, is in excellent preservation, and, 
notwithstanding its small size, every plate can be readily traced. ‘The cup 1s 
calyculate, broadly truncate at the bottom, whence it curves rather abruptly 
upward, its width slightly decreasing to the upper end. The entire length 
of the specimen is but 5 mm. by 44 mm., its greatest width, and 4 mm. across 
the top of the radials. The surface of the plates is without ornamentation, 
but sufficiently convex to bring out the suture lines. | 
Basals comparatively large, restricted to the truncated lower face of the 
calyx, and not visible from a side view; they are separated from the radials 
by six rings of plates, which increase in size upward. There are twelve 
plates in the first ring, triangular in outline, which are so minute that it 
requires a good magnifier to discover them. Another row of twelve some- 
what larger plates constitutes the second ring. The latter are jomed by 
their lateral faces, the lower angles resting between the sides of the preced- 
ing plates. Five of them are placed radially, seven interradially, one at each 
regular interradial side, and three at the anal side. Ten of the plates are 
hexagonal, the middle one of the anal side and the anterior radial one hep- 
tagonal and truncated above. The third ring consists of fourteen pieces, 
larger than the preceding ones, but less regular in their arrangement ; 
twelve of them alternate with the plates of the second ring, and the two 
others rest upon the truncated upper faces of the two larger heptagonal 
