fore el ig A ia 
260 Cincinnati Society of Natural History. 
SACCOCRINUS INFELIX, W. and M. 
(Plate VI., fig. 2, view of the left side of a cast of a moderately large specimen; fig. 2a, 
view of the cast of a vault of a small specimen; fig. 2b, shows the appearance near the top 
of the cup when the plates are preserved.) 
Megistocrinus infelix, Winchell and Marcy, 1865, Mem, Bost. Soc. 
Nat. Hist. 
Body elongated, somewhat pentangularly obpyramidal, and having 
depressed interbrachial spaces, without any constriction below the arm 
bases. | 
Basals wider than high. First radials, the largest plates of the body 
and a little longer than wide. Second radials, hexagonal and longer 
than wide. Third radials, heptagonal and longer than wide. First 
secondary radials, longer than wide. Second secondary radials, about 
as wide as long and supporting upon the upper sloping sides a single 
pair of small tertiary radials, which are followed by a single brachial 
series, and above which the arms become free. 
Regular interradials, twelve or fourteen; the first is hexagonal, and 
about the size of the second radials; this is followed by three ranges of 
two plates each ; a fourth range of three plates ; and a fifth and sixth 
range of two plates each, the latter“of which are followed by small 
plates that graduate up through the interbrachial depressions to the 
top of the vault. There are four or five inter-secondary radials that 
are followed by small plates, in like manner, to the top of the vault. 
The azygous area is much depressed in the upper part, though marked 
by a convex ridge in the middle of the depression, It is covered by 
numerous plates. The first is heptagonal and equal in size to the first 
radials. This is succeeded by three smaller plates, and these by others, 
which are continued over the convex ridge in the depression to the 
central part of the vault. 
The vault is flat in the central part, with concave depressions toward 
the interbrachial spaces at the margin, as shown by a specimen having 
the plates preserved ; the cast, however, shows the prominent radiating 
arm furrows as represented by fig. 2a. It is covered by numerous 
polygonal plates. There are twenty arms. 
This species is distinguished from S. christyi, with which it has 
been confounded, by the more elongated form of the body, by the 
more elongated plates, by the more pointed form at the base, by the 
more pyramidal and pentangular shape of the body, by the increased 
number of interbrachial plates, and by the interbrachial depressions. — 
The latter peculiarity, when the plates are preserved, is alone sufficient 
