126 GEOLOGICAL SURVEY OF THE TERRITORIES. 
Genus ERISOCRINUS Meek & Worthen. 
ERISOCRINUS TYPUS Meek & Worthen. 
Plate 33, fig. 5 a. 
Erisocrinus typus Meek & Worthen, 1866, Mlinois Geol. Rep., vol. ii, p. 317. 
Frisocrinus typus Meek, 1873, U. 8S. Geol. Sur. Nebraska, p. 146. 
LErisocrinus typus White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 89. 
The following is Mr. Meek’s description of this species, together with 
his remarks upon it, as copied from the Nebraska report above cited : 
‘“¢ Body below the summit of the first radials, basin-shaped, rounded 
below, and obscurely pentagonal in outline as seen from above or below, 
composed of thick, smooth, slightly convex plates. Basal pieces small, 
occupying a shallow concavity of the under side, about half hidden by 
the column, all pentagonal in external form. First radial pieces four 
or five times as large as the subradials, wider than long, equal, and all 
pentagonal; supporting upon their broadly and evenly truncated supe- 
rior sides the second primary radials, which are nearly of the same size. 
and form as the first, but have their sloping sides above, instead of 
below, while they each support above two first brachials, or a series of 
secondary radials yet unknown. Surface smooth. 
‘“‘ Breadth of the body below the summit of the first primary radials, 
9.72 inch; height of the same, 0.35 inch. 
‘From the slightly larger proportional size of the subradial pieces, I 
was at one time led to believe this specifically distinct from the Illinois 
specimens upon which the genus and species H. typus were founded. 
Further comparisons of additional specimens from the original locality 
near Springfield, however, showed clearly that no separation could be 
made on this character. 
“* Locality and position—The specimen figured on plate I [loc. cit.| 
was found by Dr. Hayden eight or nine years since at Bellevue, Nebr. 
The spedies was first described from the Upper Coalmeasures at Spring- 
field, Ill. We also have fragments of apparently this crinoid from Di- 
vision B, at Nebraska City.” 
Among the collections brought by Professor Powell from the middle 
division of the Carboniferous series, at the confluence of Grand and 
Green Rivers, Utah, is one example, evidently belonging to this species, 
although it is somewhat crushed, and its subradial pieces are proportion- 
ally a little larger than even those of the Nebraska specimen described 
by Mr. Meek. This Utah specimen is valuable because it possesses 
about one centimeter in length of the column, adjacent to the calyx, and 
also about two and a half centimeters in length of the arms, parts which 
have never before been known. The column is comparatively small, 
round, and composed of plates of moderate thickness, alternating with 
others which are thinner and slightly less in diameter, giving it the ap- 
pearance of being composed of segments having convex or rounded 
edges. The arms are strong, ten in number, very slightly tapering up- 
wards, flattened or slightly convex on their backs, consisting each of a 
double row of interlocking pieces, except the first one, which rests 
obliquely upon the second primary radial piece, and occupies the whole 
width of the arm. When the arms are closed they all so fit together, 
side by side, that there is only a linear or slightly impressed suture 
between them, the adjustment being as peifect between the outer sides 
of arms upon adjacent rays as it is between the inner sides of the two 
