ae IE TB ee EE 
———— = = 
ee 
en rea ater wo mens — 
. ae ee 
ae. 
Pee ole 
—= es 
= — 
= +e ee eee 
Ds a NG eT 
640 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
which we infer the root was probably from four to five inches longer. The 
branchlets are irregularly arranged; they were apparently quite long, as 
one of them, which is preserved to the length of 3 cm., retains its full thick- 
ness to the end. 
The number of arms probably varies from twenty-four to thirty to the 
ray. The latter number occurs in two of our largest specimens, while 
a smaller one in the M. C. Z., which Meek and Worthen identified as Stroto- 
crinus perumbrosus Hall, has but twenty-five. 
_ Strotocrinus glyptus Hatt. 
Plate LX. Figs. 1a, b, e, and Plate LXV. Figs. 2a, b. 
1860. Actinocrinus glyptus — Fats, ; Suppl. Geol. Rep. Iowa, p. 2. 
1881. Strotocrinus glyptus —W. and Sp. ; Revision Paleoer., Part IT., p. 160. 
A little smaller than the preceding species, the cup comparatively 
shorter, and the tegmen convex instead of flat. Calyx obconical to the top 
of the distichals, then bending abruptly outward and forming a decangular 
rim at right angles to the axis of the calyx; height to width at the rim as 
two to three. Plates convex, covered with radiating ridges, meeting at 
a small node in the centre, and communicating with the ridges from adjoin- 
ing plates. Toward the basals there are four ridges from each antero-lateral 
radial and the anal plate, and three from the anterior and two posterior 
radials; while there is but one between the other plates. Zigzag ridges, as 
in S. regalis, formed by an angular longitudinal elevation on the brachials 
in the rim, follow the lines of bifurcation, and leave angular depressions 
between. 
Basal cup twice as wide as high, the sides almost vertical; grooved 
along the sutures; axial canal moderately large and pentangular. Radials 
as wide as long, and nearly as large as both costals together. First costals 
hexagonal, the second heptagonal, shorter than the first. The brachials 
of the succeeding orders as long as wide, slightly decreasing in size up- 
wards, each one supporting at one side an arm, of which the lower plates 
are incorporated into the rim, at the other a brachial of higher rank, and 
each arm giving off pinnules whose proximal joints also take part in the rim. 
The arms proceeding from the distichals are free above the fifth plate, those 
of the palmars from the fourth. There are eight bifurcations in this species, 
giving origin to nine arms from the main branches, and eighteen from the 
“* 
