516 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
first. Arms moderately long, filiform at their upper ends; composed of | 
cuneate joints, interlocking to biserial. Pinnules comparatively strong, and 
composed of very long joints. Interbrachials: 1, 2,2; the first considerably 
larger. Anal side very wide; the first anal smaller than the radials, fol- 
lowed by a series of four other anals longitudinally arranged, and having 
at each side, and in contact with them, rows of 1, 2, and 2 plates. 
FHlorvon and Locality. — Niagara group; Hartsville, Bartholomew Co., 
Ind. 
Type in the collection of Wachsmuth and Springer. 
Acacocrinus americanus W. and Sp. (nov. spec.). 
Plate XXXIV. Figs. 150, b. 
Dorsal cup obconical, wider than high; the sides convex, spreading more 
rapidly from the top of the basals to the top of the radials; the interradial 
spaces flattened and the cross section obscurely pentangular. Plates but 
very little convex, their surfaces apparently smooth, the suture lines not 
grooved. Basals forming a shallow, slightly spreading cup. Radials as 
large as both costals together, a little longer than wide; the upper face 
concave. First costals generally quadrangular, the posterior ones occasion- 
ally pentangular; the second costals pentangular or hexangular, the angle at 
the upper face very obtuse. Distichals one only preserved in the specimen, 
quadrangular in outline, as long as the costals but much narrower. First 
interbrachial almost as large as the radials, and about as wide as long; the 
second row consisting of two much smaller plates. Anal plate somewhat 
smaller than the radials, and the three plates above not more than half the 
size of the first interbrachial of the regular sides; the succeeding row con- 
sisting of three pieces of the size of the distichals. All other parts unknown. 
Horizon and Locality. — Niagara group; St. Paul, Ind. 
Type in the collection of Wachsmuth and Springer. 
COMPSOCRINUS &. A. Minter. 
1883. 8. A. Mitzter; Journ. Cincin. Soc. Nat. Hist., Vol. VI., p. 233. 
Syn. Glyptocrinus (in part) —Mitier; 1881; ibid., Vol. IV. (April number), Plate I., Fig. 6. 
Syn. Mariaerinus (in part) — W. and Sp.; 1885, Revision Paleocr., Part III., p. 104 (Proceed. 
Acad. Nat. Sci. Phila., 1885, p. 326). | 
In its general habitus resembling Glyptocrinus, but having an anal plate 
between the radials, and only four basals. Basals large, unequal, two of 
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= — — ~ = = 5 S - . - - 4 : - 
