RHODOCRINID®. 221 
it differs in the mode of branching of the arms, and the fact that the latter 
has convex calyx plates; also in its basal concavity being much deeper, 
the column larger, and calyx higher. 
Rhodocrinus Wortheni, var. urceolatus W. and Sp. 
Plate XIT. Figs. Sa, b. 
Differing from the typical form of R. Wortheni in the form of the calyx, 
which is urn-shaped instead of globular, higher than wide and rounded at 
the bottom, while that is flattened. ‘lhe infrabasals are convex, and on 
a level with the basals. The greatest width of the calyx is across the first 
costals, whence it contracts rapidly to near the arm bases, which slightly 
project outward, giving to the tegmen a decidedly pentangular outline. 
Ventral disk almost flat, wider than in the typical form, and the plates less 
numerous. Anus subcentral, and not protuberant. The plates of the calyx 
flat and without ornamentation. 
Horizon and Locality. — Age of the Lower Burlington limestone, Lake 
Valley, New Mexico. 
Types in the collection of Wachsmuth and Springer. 
Rhodocrinus watersianus W. and Sp. 
Plate XI. Fig. 9. 
1889. W. and Sp.; Geol. Rep. Illinois, Vol. VIII., p. 184, Plate 17, Fig. 16. 
A small species of the type of Rhodocrinus Wortheni, from which it differs 
in the more concave base, the proportionally smaller size of the basals, in the 
more elongate form of the calyx, and in the arm structure. Calyx from 
sub-globose to sub-ovoid, truncate at the bottom and narrowly concave ; 
plates very slightly convex, and without ornamentation. 
Infrabasals small and concealed by the column. Basals moderately large, 
their lower ends abruptly deflected inward, their upper portions curving out- 
ward and upward. Radials somewhat smaller than the basals; as wide as 
long. Only the proximal distichals take part in the calyx; they are followed 
by five to six slightly cuneate free plates, of which the upper one is axillary, 
and supports two arms, which remain simple. Arms twenty, rounded on the 
back, slender, very little tapering, and biserial from the last bifurcation ; the 
joints moderately high and a little convex. Pinnules stout for the genus. 
The first interradial plate as large as the radials; followed by five to six 
