PLATYCRINID &. 677 
SARA! GROUP. 
The plates of the dorsal cup smooth or obscurely granulose ; the inter- 
basal sutures raised into ridges by excessive secretion of calcareous matter 
during anchylosation ; the stem with internodal joints. 
Platycrinus Saree Hatt. 
Plate LXIX. Fig. 7, and Plate LXX. Fig. 1. 
1858. Haun; Geol. Rep. Iowa, Vol. I., Part IL, p. 673, Plate 18, Fig. 4. 
1881. W.and Sp.; Revision, Part II., p. 74. 
Syn. Platycrinus Georget, Hat; Suppl. Geol. Rep. Iowa, p. 82. 
Syn. P. prattenanus M. and W.; Geol. Rep. Illinois, Vol. I1., p. 264, Plate 20, Fig. 2. 
Syn. P. monroensis WortuEn; idid., Vol. VIIL., p. 306, Plate 30, Fig. 9. 
Dorsal cup goblet shaped, gibbous in the middle, broadly truncate at the 
base. Surface of plates smooth, or covered with a few obscure ridges passing 
out from the facets to the lower angles of the radials. 
Basals forming a saucer-shaped dish, occupying fully one third the height 
of the dorsal cup; the lower end broadly truncated, the outer margin pro- 
jecting and forming a rim; the lower face a little concave, and wider than 
the upper stem joints. Interbasal sutures distinctly elevated above the gen- 
eral surface, and formed into ridges. Radials quadrangular, as wide as long, 
and as wide at the lower end as at the upper. Facets deeply indented, em- 
bracing the costal and one or both distichals. Costals very small, triangular. 
Distichals once and a half as wide as long, giving off an arm to the outer 
side of the plates, their inner sides two palmars with two arms, making six 
arms to the ray. Arms biserial from the second or third joint, of moderate 
size ; the tips somewhat tapering. Pinnules very long and closely set; their 
joints more than twice as long as wide. Structure of the ventral disk un- 
known. Column very slightly oval; composed of nodal and internodal 
joints, the former wider and higher than the internodals. Whether the 
upper and lower faces of the joints have transverse ridges could not be 
ascertained from the specimens. 
Horizon and Locality. — St. Louis group; St. Louis, Mo., and Jersey 
Corelli: 
Types in the (Worthen) Illinois State collection, Springfield. 
Remarks. — P. Sare was described from a very large, somewhat crushed 
specimen, showing indistinct traces of ornamentation; P. Georgii from a dis- 
