342 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
outer margin; the basals very small, occupying only the bottom part. 
Radials very long, only half their length exposed to view; the attenuate 
longer half incurving and forming the sides of the concavity; the exposed 
part wider than high. First costals quadrangular, their width once and a 
half their length; the second a little larger and hexangular, their upper 
angle broadly truncated by the interdistichals. Distichals nearly of equal 
size, and almost as large as the axillary costal; the upper angle of the 
second so extremely obtuse as to almost form a straight line; the fixed 
palmars moderately large and quadrangular. First interbrachial large, 
generally as wide as long; the upper part broadly truncated by the two 
plates of the upper row, which together are as large as the first, and rise to 
the second arm plate. Interdistichal rather narrow and long. Partition 
walls narrow, not more than half the width of the arms, except their upper 
ends which widen conspicuously toward the summit. Summit somewhat 
flattened ; the central space closed by a short pyramid of small plates. The 
arms rounded on the back, projecting slightly over the sides of the parti- 
tions; the three proximal plates single, and higher than the succeeding ones 
which deeply interlock. 
Horizon and Locality. — Niagara group ; Decatur and Wayne Cos., Tenn. 
Types in the Museum of Comparative Zotlogy, and in the collection of 
Wachsmuth and Springer. 
vemarks. — This species differs from £. celatus, to which Roemer 
referred it provisionally, by the much more depressed form of the dorsal 
cup, the proportionally greater length of the arms, the form and size of the 
various plates, and the mode of ornamentation. 
Eucalyptocrinus crassus Hatt. 
Plate LXXXTI. Figs. 1, 2, 3, 4, 5, 6, 14, 15. 
1863. Hau; Trans. Albany Inst., Vol. IV., p. 197; also 20th Rep. N. Y. State Cab. Nat. Hist., p. 323, 
Plate 11, Figs. 2, 3 (second ed., p. 365); also, 28th Rep. (second ed.), p. 141, Plate 17, 
Figs. 1-11, Plate 18, Figs. 1-9, and Plate 19, Figs. 2-5. 
1875. (2) Hats and Wurtrrerp; Geol. Surv. Ohio, Paleont., Vol. IL, p. 129, Plate 6, Fig. 11. 
1881, Coruer; 11th Ann. Rep. of Geol. and Nat. Hist. of Indiana, p. 272, Plate 17, Figs. 1-11, Plate 
18, Figs. 1-9, and Plate 19, Figs. 2-5. 
Syn. Lucalyptocrinus constrictus, Tat ; ibid., p. 278, Plate 15, Fig. 1. 
Syn. Eucalyptocrinus chicagoensis, Wrxcu. and Marcy ; 1865, Mem. Boston Soe. Nat. Hist., p. 90. 
A large species; the crown sometimes reaching a length of 10 cm. by 
6 cm. in width; its length, as a rule, twice the width; the length of the 
