o 
SS SS ———S ee 
THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
fl 
cae | 
4 
Dichocrinus pendens W. and Sp. (nov. spec.). 
Plate LX XVIII. Fig. 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. Radi- 
als nearly once and a half as wide as long, widest at. one third their height, 
the sides being distinctly 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 | 
a 
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 Locality. — Upper Burlington limestone; Burlington, Towa. 
Types in the collection of Wachsmuth and Springer. | 
fiemarks. — Distinguished from all preceding species by the pendent 
arms, which is a constant feature in half a dozen specimens. 
Dichocrinus ficus Cass. and Lyon. 
Plate LXX VILL, Figs. 16a, b. 
1860. CassEpay and Lyon; Proceed. Amer. Acad. Arts and Sci., Vol. V., p. 24. 
1873. Merk and Worruen; Geol. Rep. Illinois, Vol. V., p. 502, Plate 14, Figs. 5a, 4 (not ibid., Vol. VL, 
Plate 29, Fig. 7). 
1881. W. and Sp.; Revision Paleocr. Part IT., 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. 
