26 Mr. W.H. Baily on a new Pentacrinite 
like thick plates, having a double exeavation at their lower ex- 
tremity, where they articulate with the pentagonal stem ; radial 
plates five in number, about twice as broad as long; brachial 
plates also five, broad and triangular, supporting the rays, 
which are ten in number, very long, composed of cuneiform 
alternating articulations, and bifurcating four or more times, 
every alternate joint of these rays being furnished with a long, 
slender, eight-jointed pinnule. The column consists of a num- 
ber of pentagonal joints, of equal length, each united by a cre- 
nulated margin, and for the greater portion of its length com- 
paratively smooth, but towards the calyx becoming strongly 
ridged and beaded across the exterior surface of each angle. At 
about every eighth joint on each of its five angles a closely-jointed 
ramule was articulated. 
hig of small specimen.—Length of calyx +45, diame- 
ter 2, inch. Diameter of column rather less than 34, inch. 
Length of rays about 2 inches; length of column nearly 5 inches 
(probably much longer when perfect). 
yrenmnenns of larger specimen.—Length of calyx 3, diameter 
*, inch. Diameter of largest fragments of column 5%, nob ; 
athe portions vary in diameter from rather less than aa to 
inch. 
sh ere —This Pentacrinus is remarkable for its graceful 
form, which it owes to the slender stem and great propor- 
tionate length of its arms ; the calyx, like that of the typical and 
recent example of this genus (Pentacrinus caput-Meduse) is 
small, and composed of but few plates, the basal series or pelvis 
consisting of five very convex and solid elements, the lower por- 
tion of each being excavated to form an articulating surface, 
which rests securely upon the pentagonal stem; to these are 
closely fitted the five radial plates; upon them rest the five 
triangular brachial plates, the sides of which support the long 
rays or arms, which bifurcate several times, and are ten in num- 
ber; commencing from the brachial plate, they continue for 
about three-tenths of an inch to the first subdivision, consisting 
of from eight to ten irregularly-shaped joints closely fitting to 
each other and bearing a second triangular plate, the sides of | 
which, like that of the first brachial plate, support the second 
division, one branch of which, consisting of fifteen joints, again, 
bears the third triangular plate, from which springs a third 
subdivision ; to one of the branches of this division sixteen more 
joints can be counted without any further branching, the termi- 
nation of this, the best-preserved of the arms, being still want- 
ing. The plates composing the rays become flatter and more 
closely set towards their upper part, their surfaces bemg marked 
by a continuous double line or angular ridge (PI. I. fig. 1h). 
