228 Cincinnati Society of Natural History. 
body, a free arm, before reaching the top of the vault. The inter- 
radial and intersecondary radial areas are not depressed, uor the 
general obconoidal form of the body, interrupted except by the stand- 
ing out of the arms above the second secondary radials. The arms 
bifurcate at once, upon becoming free, and three times afterward. 
The character of the vault is unknown, but if its general structure 
is essentially distinct from other species of Glyptocrinus, the species 
must be referred to another genus. 
It occurs in the upper part of the Hudson River Group. 
GAUROCRINUS, D. gen. 
[Ety. gauros, haughty, proud; krinon, a lily.] 
This genus is established to receive those species heretofore referred 
to Glyptocrinus, but which have basal and subradial plates. It may 
be defined as follows : 
Column round or pentagonal, and composed of thinner and thicker 
plates. Calyx having strong radial ridges, and depressed interradial 
and intersecondary radial areas. Basals, five, presenting a low tri- 
angular face on the exterior, or having slightly truncated lateral 
angles. Subradials, five, heptagonal, height and width subequal. 
Primary radials, three by five, or as in the type, the left posterior ray 
may have only two. Secondary radials, ten to sixteen by ten. Ia- 
terradial and intersecondary radial areas covered by numerous small 
plates. Azygous area supported by a ridge up the middle series of 
plates, gradualiy becoming obsolete as it approaches the vault. Vault, 
covered by numerous small plates, which are continued as a covering 
over the ambulacral furrows. Arms, twenty or more, possessing 
pinnules. Type, Gaurocrinus nealli, which will be particularly 
defined. 
GAUROCRINUS NEALLI (HALL). 
Column sharply pentagonal, and composed of alternating thin and 
thicker plates. Basals, smail, pentagonal, presenting a low triangular 
face on the exterior, slightly truncated at the lateral angles, and not 
interfering with the pentalobate character of the calyx when viewed 
from below. Subradials about as wide as high, except the one on the 
azygous side, which is longer than wide; each bears a semi-cylindrical 
three-rayed ridge, highest in the central part, and sending one arm 
below to meet the angle of the column, and one to each of the adjoin- 
ing radials to meet corresponding ridges, except as to the azygous 
