a # ee hy - — 
et 
Eucladocrinus pleuroviminus Wautre. 
<a 
Plate LXXIII. Fig. 4, Plate LXXIV. Fig. 1. 
| . 1862. Platycrinus pleuroviminus —WuitE; Proceed. Bost. Soc. Nat. Hist., Vol. IV., p. 17. 
1878. Hucladocrinus pleuroviminus —W. and Sp.; Proceed. Acad. Nat. Sci. Phila., p. 244, and 1881, Re- 
vision, Part IL., p. 77. 
Syn. Platycrinus discoideus Hai; 1858 (not Owen and Suu. 1852); Geol. Rep. Iowa, Vol. L., 
Part IL., p. 535, Plate 8, Figs. 8a, d. 
724 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
| 
ail in gees 
LL OOETEN. ag LIRIK oe - 
See EE 
ee: 
A very large species; the calyx sometimes reaching a width of 60 mm. 
The form of the dorsal cup extremely variable, from discoid to low cup- 
shaped, and from distinctly decangular in its dorsal aspect to almost circular ; 
SS Ea Se 
oe 
its height in some of the specimens scarcely a third of the width, in others 
| equal to one half. Plates of the cup very heavy, and frequently highly orna- 
mented over the whole surface, sometimes only around the margins; while in 
iT some cases they are almost devoid of any surface markings whatever. In 
most of the specimens, however, the surface is covered by irregular wrinkles 
aa and rugose ridges parallel to the margins of the plates, and similar ridges pass 
from the lower edge of the radial facets to the inferior angles of the radials, 
a3 and from the column to the upper angles of the basals. Other specimens 
saa have a broad, roughened single ridge at some distance from the margins of 
| the plates, and deep grooves at either side of it; but in all of them the 
| } | edges of the plates are distinctly beveled, and the basi-radial and interradial 
Hee | | | suture lines channeled. Ventral disk as high as the dorsal cup, and some- 
times a little higher, its outer margin rising almost vertically from the upper 
Ave edges of the radials; the median portions depressed. The species has ten 
aes 
eee a rr 
—— 
aa | . arm trunks given off from the radials almost horizontally, those of the same 
ray being in sutural contact to the top of the first palmars; they are quite 
i 
ig heavy at the proximal end, but taper gradually upward, and curve gently 
| from above the palmars upwards and inwards, supporting from the side of 
every second plate a simple arm. 
Base pentagonal, with a funnel-shaped depression occupying two thirds 
the diameter of the plate, the margin convex and on a level with the beveled 
me? lower end of the radials. The interbasal suture lines more or less deeply 
- op l- grooved, the basi-radial and interradial ones at the bottom of a broad, shal- 
| low channel. Radials moderately spreading, the lower face wider than the 
@ it lateral ones, the upper end slightly inflected to meet the interambulacral 
plates, and the angles broadly truncated for their reception; the plates 
