HEXACRINIDZ. 709 
Dichocrinus oblongus W. and Sp. (nov. spec.). 
Plate LX XVII. Fig. 9., 
In the style of ornamentation resembling D. striatus, from which it differs 
essentially in its very elongate calyx, and in the proportions of the plates. 
Calyx almost twice as high as wide, obconical, not contracted at the upper 
end; the sides convex. Surface covered by six sets of from five to six rather 
prominent, longitudinal ridges, which in gentle curves pass from the facets 
of the radials and top of the anal plate to the foot of the basals. These 
ridges do not cover the entire surface of the calyx, but leave upon the lateral 
margins of adjoining radials a trigonal space, divided by the interradial 
suture, and covered by obscure, longitudinal ridges, which rest obliquely 
against the other ridges. 
Basal cup conical, almost as high as the radials, and nearly as high as 
wide; slightly truncated at the bottom; the upper face but little excavated. | 
Radials once and a half as long as the width of the lower end, a little wider 
above than below, the lower face almost straight ; facets narrow, a little 
concave, and slightly protruding outward. Structure of arms and ventral 
disk not known. 
Horizon and Locality. — Warsaw limestone, near Bloomington, Ind. 
Type in the collection of Wachsmuth and Springer. 
Dichocrinus liratus Hatt. 
Plate LXXVITI. Figs. 3a, 6, and Plate LXXVI. Fig. 8. 
1860. Hatt; Prelim. Descr. of New Paleoz. Crin., p. 5. 
1861. Hatt; Bost. Journ. Nat. Hist., Vol. VII., p. 290. 
1872. Hai; N. Y. State Mus. Nat. Hist. (Bull. I.), Plate 2.4, Figs. 7, 8. 
1881. W. and Sp.; Revision Paleocr., Part II., p. 84. 
Of the type of D. polydactylus and D. lachrymosus, differing from the 
former in having four or five instead of six to eight arms to the ray, and 
showing a tendency toward the rhombic sculpturing of D. striatus. Calyx 
abruptly spreading to the basi-radial suture, and more moderately from 
there to the arm bases, at which the width is about equal to the length. 
Surface marked by a few strong radiating ridges, somewhat tending to form 
fo) (So) 2 ran) 
triangles or rhombs, modified by transverse lines; composed of small, closely 
