Tee. er ee he a ay er Oe ee 
New Species of Fossils and Remarks upon Others. 169 
2-10ths of an inch, there is a slight expansion, and the height is repre- 
sented by the length of about four interbrachial plates. The arms 
arise at the point of constriction, but do not become free, until they 
reach the top of the vault. The double series of brachial plates, which 
thus form part of the cup, project beyond the interbrachial plates and 
leave depressed interbrachial areas. 
Interradials.—The first regular interradials are hexagonal, a little 
smaller than the first radials, and succeeded by about 16 plates, ar- 
ranged, irregularly, into pairs, before reaching the point of constriction ; 
and from this point to the top of the expanded vault, and between the 
bases of the arms, there are about twenty interbrachials. 
Intersecondary radials.—The first intersecondary radial is hexag- 
onal, and a little smaller than the first secondary radial; it is succeeded 
by three pairs of plates which gradually diminish in size to the point 
of constriction, and from this point to the top of the vault there are 
about twenty interbrachials. 
Azygous interradials.—The azygous area below the constriction, 
contains 44 plates, and has the appearance of two regular interradial 
areas, separated by a single series of plates. The first azygous inter- 
radial is heptagonal, rests between the sloping sides of the basals, and is 
like the heptagonal first radials. From the upper side a series of nine 
plates, part of which are hexagonal, and the others heptagonal, extend 
to the constriction. Between the upper sloping sides of the first azy- 
gous interradial and the adjacent interradials, on either side there is an 
hexagonal plate which is succeeded by 16 plates, arranged, irregularly, 
into pairs, very much as they are in the regular interradial areas. 
Vault.—The vault is flat, with the exception of a very small central 
proboscis, and a slightly elevated ridge, extending from it to the margin 
and down the middle of the azygous area, as shown by a specimen pre- 
serving part of the plates. The cast shows a star-like figure on the outer 
part of the vault with ten rays, extending to the arm furrows, without 
bifurcation. The vault is covered with numerous, small, polygonal, 
plates, 
Arms.—There are only ten arms in this species, though there is 
evidence that the arms bifurcated at the top of the vault. 
The formula is as follows: 
IIS le be SA Ro ee aha 
eS) Go DE ao, Ae Sneha 15 
Oe Ti ONTENTS) 0 OES ee ee 40 
Mreeia IbenbAGIals) 1X4 vx a 468 
