772 THE CEINOIDEA CAMERATA OF NORTH AMERICA. 



Dichocrinus Ulrichi Millee and Gukley. 



1S90. Joum. Ciucin. Soc. Nat. Hist., Vol. XHI. (Author's Ed., p. 48), Plate 8, Figs. 12 and 13. 



A small species. Calyx subovoid, once and a half as high as wide, 

 somewhat constricted at the upper end, pointed at the lower; the plates 

 smooth. Basals large, forming a high obconical cup, with a deep notch at 

 the anal side ; the column facet small. Eadials nearly twice as long as wide, 

 spreading upwards, reaching their greatest width at three fourths their 

 height, contracting at the upper end; the sides slightly depressed, leavino- 

 the sutures rather distinct ; facets narrow, and occupying but one third the 

 width of the radials. Costals two, apparently united by syzygy, as well as 

 the two proximal distichals, both being so clo.sely united that the lines are 

 frequently invisible. Arms two to the ray, rather long and comparatively 

 stout; they are composed of single joints, of which the upper and lower 

 edges are almost parallel, and not so decidedly cimeate as figured by Miller 

 and Gurley. Pinnules coarse, long, and closely packed. Fii'st interbrachial 

 plates visible in a side view. Anal plate a little longer and narrower than 

 the radials. 



Horizon and Locality. — Upper part of the Keokuk group ; Bono, Law- 

 rence Co., Ind. 



Type in the collection of Wm. F. E. Gurley, 



Remarks. — This species resembles so closely Dicliocrinus scUulus from 

 the Upper Burlington limestone, that we doubt if the two forms represent 

 different species. We find it impossible to separate them in our collection, 

 in which we have specimens from both horizons. 



Dichocrinus Hamiltonensis Wokthen. \ 



Plate LXXVI. Fig. 10. 



1882. Bulletin I., Illinois State Museum Nat. History, p. 35. 



1883. Geol. Rep. Illinois, Vol. VII., p. 318, Plate 27, Kg. 10. 



A little larger than the preceding species. The specimen from which the 

 description was made, and the only one known to us, is badly crushed, and 

 the exact proportions of the calyx cannot be given. From its appearance, 

 however, we take the length of the dorsal cup to be about equal to its width, 

 and the height of the basals about half that of the radials. The latter are 

 subquadrangular, narrower at the lower end, the length equal to their 



