A474. THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
the radials; wider than high, and spreading but little at the sides. Plates 
moderately convex, without ornamentation; suture lines well defined, with a 
small pit at each angle of the plates. Color of specimens as in A. awumaturus. 
Basals forming a disk, which rests within a shallow concavity formed by 
the united radials, and not visible in a side view. Radials large, heptagonal, 
narrow below and wide above, the lower end curving inward. Costals small, 
nearly of equal size. Distichals unevenly distributed among the rays, the 
three anterior rays having from two to three in the calyx, which are fol- 
lowed by free arm plates; the two posterior rays, in the division next to 
the anal side, but one, which is axillary and followed by two fixed palmars ; 
the opposite side having three distichals, thus making fourteen arms to the 
species. Arms arranged in groups, the space between the posterior rays 
much the widest; they are quite robust, tapering at the end, rounded, and 
biserial except one or two cuneate pieces at the base. Interbrachials in two 
ranges; the first very large, reaching the top of the costals, and touching the 
distichals, the others small, resting between the distichals. A third range 1s 
on a level with the arm bases, and followed in four of the areas by four to 
five interambulacrals. Anal area very wide, elevated along the median line, 
deeply grooved at each side, so as to form from the distichals to the posterior 
oral a longitudinal ridge, which is most prominent in the upper part around 
the anus. First anal plate larger than the radials, longer than wide; the 
second, and the interbrachials at the sides, as large as the corresponding 
single plate of the other areas; the plates above small and irregular in 
their arrangement. ‘Tegmen depressed convex. Orals large; the posterior 
one extended into a thick, elongate node, and twice as large as the others, 
which are moderately convex. Anal opening directed laterally. The food 
grooves and their branches, respectively, are covered by a single plate. The 
stem apparently was longer than in the two preceding species, and less taper- 
ing. The nodal joints are a little wider than the intervening ones, which 
increase very rapidly in number, there being six to the internode at an inch 
from the calyx, which appears to be the maximum number. 
Horizon and Locality. — Same as last. 
Types in the collection of Wachsmuth and Springer. 
