HEXACRINID^. 767 



Basal cup about two thirds as high as the radials; the salient angles 

 obtuse and the intervening spaces very little concave ; column facet small. 

 Eadials from one third to one half longer than wide ; irregular in form, some 

 of them much wider above than below, others of nearly equal width through- 

 out; the upper faces distinctly slo|)ing at the sides, forming rather deep 

 notches for the reception of the interbrachials ; facets but slightly excavated, 

 occupying a little more than one third the width of the plates. Anal plate 

 generally narrower than the radials. Costals two, comparatively large, 

 supporting two simple arms, which from the third or fourth plate up are 

 composed -of two series of transverse pieces alternately arranged. The arms 

 are heavy throughout, biserial, and rounded on the back. Pinnules cylin- 

 drical, very long and stout. All other parts unknown. 



Horizon and Locality. — Kaskaskia group ; Pulaski Co., Ky., and Hunts- 

 ville, Ala. 



Ti/pe in the collection of Wachsmuth and Springer. 



Remarks. — The form of the calyx, thickness of plates, deep notches for 

 the reception of the interradials, and the stoutness of the arms, are characters 

 which distinguish this species readily from D. cMicatus. 



Dichocrinus scitulus Hall. 

 Plate LXXVIII. Figs. 13a, h, and I4. 



1861. Hall; Joum. Bost. Soc. Nat. Hist., p. 2S9. 



1872. Hall; N. Y. State Museum Nat. Hist., Bull. I., Plate 3^, Figs. 12 and 13. 



1881. "W. and Sp. ; Revision Palseocr., Part II., p. 84. 



Syn. Dicliocrimis pocillam Hall, 1801 ; Joum. Bost. Soc. Nat. Hist., p. 291 ; figured Bull. I. N. Y. 

 State Mus. Nat. Hist., Plate 2 A, Figs. 16 and 17 (not 11 = D. lieois). 



Larger than the two preceding species, the calyx more conical, the radials 

 comparatively shorter. Calyx obconical, less rapidly spreading at the radials 

 than along the basals. Plates thin ; their surface smooth or finely corrugated. 



Basal cup nearly one half the height of the calyx to the arm bases ; 

 column facet small, circular, slightly projecting. Eadials a little wider than 

 long, narrowest at the lower end, the upper face but little sloping at the 

 sides ; somewhat elevated longitudinally in the middle, forming an obscure 

 ridge, which disappears before reaching the basals ; facets semi-circular, nar- 

 row, occupying less than one-third the width of the plates at the top. 

 Costals small, bending outward ; the first very short, linear ; the second 

 depressed pentagonal, sharply angular at the top. Distichals divergent, as 

 long as wide, and almost as wide as the costals ; the second one axillary. 



