230 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Rhodocrinus Barrisi Hatt. 
Plate XII. Figs. 3, 4a, b,c, d; and da, b. 
1861. Hatz; Prelim. Notice of New Spec. of Crin. (Albany), p. 9. 
1861. Haxx; Boston Journ. Nat. Hist., Vol. VII. (No. 2), p. 322. 
1872. Haut; N. Y. State Mus. Nat. Hist., Bull. 1, Plate 6, Figs. 16, 17. 
1881. W. and Sp.; Revision Paleoer., Part IT., p. 212. 
Syn. Rhodocrinus Barrisi, var. divergens Hatt, 1861; Boston Journ. Nat. Hist., Vol. VIL., p. 
324; and N. Y. State Mus., Bull. 1, Plate 6, Fig. 18. 
A very variable species, of the style of Gilbertsocrinus. Calyx forming 
a polyhedron, with slightly impressed faces and a node at each angle. Dorsal 
cup broadly truncate at the bottom, widest at the middle of the radials, 
whence it tapers rapidly and uniformly to the margins of the tegmen, whose 
diameter is from one third to one half smaller than that of the widest part 
of the dorsal cup, and less than the diameter at the truncated lower part. 
Plates highly elevated, their middle portions crowned with spine-like pro- 
cesses or elongate nodes, connected by well marked ridges, which traverse 
the sutures and meet with the nodes of adjoining plates. The nodes upon 
the basals are longer, attaining in very mature specimens a length of four to 
five mm. by two mm. wide; they are directed obliquely downward, while those 
from the radials, costals, and interradials point horizontally. In less mature 
specimens, as a rule, the nodes are comparatively smaller. The ridges 
connecting the basals form around the bottom of the calyx a well defined 
pentagon, with a shallow concavity occupying the whole width of the lower 
face, enclosing the infrabasals and fully one third of the basals. 
Infrabasals small, but their upper angles visible beyond the column. 
Basals proportionally large ; their upper half abruptly bent upwards so as 
to take part in the lateral walls, and forming a sharp edge on which the 
calyx rests. Radials a little smaller than the basals. Costals very small ; 
the first less than one third the size of the radials, but twice as large as the 
second. Distichals eight to twelve; the plates of the first row, and some- 
times those of the second, incorporated into the calyx and in contact later- 
ally. The free distichals short, cuneate, and in large specimens interlocking ; 
the upper one axillary, supporting two arms, of which either one or both are 
branching once again. Arm openings elongate ; arranged in pairs ; directed 
horizontally. Arms about twice as long as the height of the calyx; cylin- 
drical ; somewhat divergent; the plates sharply cuneate and interlocking. 
