774 THE CBINOIDEA CAIIEEATA OF NORTH AjMEEICA. 



Dichocrinus pendens w. and Sp. (nov. spec). 

 Plate LXXVIII. Fie/. 15. 



Of medium size. Calyx apparently subovoid, a little higher than wide; 

 the plates very delicate and without ornamentation ; the suture lines not 

 grooved ; the arms pendent. 



Basal cup bowl-shaped, the plates a little shorter than the radials. Eadi- 

 als nearly once and a half as wide as long, widest at one third their height, 

 the sides being distinctlj^ convex ; radial facets directed upwards, rather 

 shallow, but wide, and occupying four fifths the width of the plates at the 

 upper end. Costals two, short, the upper wider than the lower. Distichals 

 two, axillary, giving off four arms to the ray. The arms from the fourth or 

 fifth palmars curve abruptly downward in such a manner as to envelope the 

 calyx and the upper part of the stem, exposing the ventral furrows of arms 

 and pinnules. Arms ten, biserial at the upper ends, the lower arm joints 

 cuneate, alternately arranged. Pinnules stout, long, and flattened. Column 

 round ; the nodal joints wider and longer than the internodals, the latter, 

 so far as observed, consisting of a single ossicle to the internode. 



Horizon and Localiiij. — Upper Burlington limestone; Burlington, Iowa. 



Tii])es in the collection of Wachsmuth and Springer. 



Remarks. — Distinguished from all preceding sjjecies by the pendent 

 arms, which is a constant feature in half a dozen specimens. 



Dichocrinus fictlS Cass, and Lyon. 

 Plate LXXVIII. Figs. 16a, h. 



I860. Cassedat and Lyon ; Proceed. Amer. Acad. Arts and Sci., Vol. V., p. 2i. 



1873. Meek and Wortsen ; Geol. Rep. Illinois, Vol. V., p. 502, Plate 14, Figs. 5b, b (not ibid.. Vol. VI., 



Plate 29, Fig. 7). 

 1881. W. and Sp. ; ReTision Palsocr. Part 11., p. 83. 



A small and very slender species. Calyx ovate, twice as long as wide, 

 widest near the middle of the radials, whence it curves gradually and evenly 

 to the end of the basals, and somewhat more rapidly to the arm bases. 

 Plates smooth, without markings, except a small angularity following up and 

 down the median portions of the radials. 



Basals formed into a deep, obconical cup, about as high as wide ; only 

 truncated for the reception of the column, the lower face slightly concave. 



