PLATYCRINID 2. 683 
-Platycrinus bonoensis Wutrs. 
Plate LXIX. Fig. 6. 
1878. Wutre; Proceed. Acad. Nat. Sci. Phila., p. 30; and 1880, U. 8. Geol. Surv. Terr. by Hayden, 
Contr. to Paleont. No. 5, p. 160, Plate 40, Fig. 5. 
1881. W. and Sp.; Revision, Part II., p. 70 (Proceed. Acad. Nat. Sci. Phila., p. 244). 
Syn. P. eternalis 8. A. Mitumr, 1891; Geol. Surv. Missouri, Bull. 4, p. 11, Plate 1, Fig. 8. 
Syn. P. caducus 8. A. Mittmr, 1892; Adv. Sheets 18th Rep. Geol. Sury. of Indiana, p. 13, Plate 
2, Fig. 18. 
Closely allied to the preceding species, but having five to six arms to the 
ray instead of four, and these are proportionally shorter, more closely packed, 
and heavier. Dorsal cup wider than high, bowl-shaped, a little spreading, the 
margins of the plates slightly beveled, giving to the central portions a slight 
convexity. Surface without ornamentation. 
Basals proportionally small, forming a shallow basin, broadly truncated 
below and excavated at the bottom, the sides somewhat constricted so as to 
form a rounded projecting edge around the lower margins; the interbasal 
suture lines slightly elevated. Radials wider than long, gradually expanding 
upwards, the upper angles truncated, deeper at the anal side. Facets from 
one half to two thirds the width of the radials; semicircular. Costals small, 
trigonal, rarely covering the full width of the facets, and the distichals abut 
against the radials. First distichals once and a half as wide as long, the 
axillary one a little wider and somewhat higher. The latter gives off an 
arm to the outer side of the ray, and supports at the inner two palmars with 
two arms, making three arms to each subdivision, or six to the ray, excep- 
tionally five. The arms are stout, especially in the middle, and quite short; 
they are uniserial to the fourth plate, beyond this biserial. Column slightly 
elliptic, and twisted. 
Horizon and Locality. —Uppermost part of the Keokuk group and lower 
beds of the Warsaw limestone, Bono, Lawrence Co., Ind., and Boonville, Mo. 
Types in the collection of W. F. E. Gurley, and R. A. Blair at Sedalia, Mo. 
SUBSPINULOSUS GROUP. 
Basal cup almost as high as the radials, subcylindrical. Surface of plates 
smooth or ornamented. 
