260 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Horizon and Locality.— Upper portion of the Trenton limestone; Trenton 
Talls, N. Y. 
Type in the Museum of Comparative Zotlogy, Cambridge. 
Rhaphanocrinus sculptus (Mitter). 
Plate X. Fig. 3. 
1882. Glyptocrinus sculptus—S,. A. Mitter; Journ. Cincin. Soc. Nat. Hist., Vol. V., p. 37, Plate L., 
1883. pene sculptus —S. A. Mitter; ibid., Vol. VI., p. 224. 
1885. Glyptocrinus sculptus — W. and Sp.; Revision Paleocr. Part III., p. 104. 
1889. Glyptocrinus sculptus—S. A. Mitten; N. Amer. Geol. and Paleont., p. 248. 
Calyx subglobose; interradial spaces deeply depressed, especially the 
upper portion; section across the second costals sharply pentagonal, across 
the distichals decagonal. Radial ridges quite prominent, angular, stronger 
toward the sutures than at the median portion of the plates. Somewhat 
smaller ridges pass into the basals, forming deep triangular depressions along 
their sides. Other ridges run from the radials and brachials to the inter- 
radial plates, dividing the whole surface into numerous impressed triangular 
areas. 
Infrabasals almost covered by the column. Basals of medium size, pro- 
duced into angular processes, which point downward for a short distance 
along the sides of the upper stem joints. Radials and costals about as wide 
as long. Distichals three, almost as large as the costals. The plates of the 
third order support the arms, of which there are twenty; they are long, 
eradually tapering, and composed of quadrangular joints which become 
slightly cuneate in the upper parts of the arms. The four to five lower 
joints, which are considerably the largest and sharply angular on the out- 
side, take part in the calyx; the succeeding ones are free, much shorter, and 
rounded. Pinnules long and slender. Interradial spaces deeply depressed 
between the distichals; the plates arranged: 1, 2, 3, 3, etc. The anal side, 
which is a little wider, has a few additional plates, but no anal ridge. Inter- 
distichals: 1, 2, 1. Structure of ventral disk unknown. Column round, 
slightly tapering downwards, the nodal joints, near the calyx, wider and 
considerably longer than the intervening ones, but at two inches below the 
latter reach almost the same size. 
FTorizon and Locality. — Upper part of the Hudson River group; Warren 
Co., Ohio. 
Types in the collection of I. H. Harris, Esq., at Waynesville, O. 
