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and placed on the anal side, have six sides, two of which are very short/ One 
of these hexagonal pieces is very like the three pentagonal pieces, hut the 
other seems to he distorted and thrown more to one side than the other. It 
is this conformation which makes the calyx appear gibbous, and, when in 
horizontal section, oval, instead of circular like most Crinoidea, its anal side 
not following the circular curve of the other sides. All the pieces are rather 
longer than broad. The primary radials are a little wider than long, espe- 
cially towards their articular extremities, which are much elongated. There 
are only three primary radials, which constitutes a decided anomaly in the 
general structure of Crinoidea ; the sides are also strongly contracted towards 
their upper extremity. The very shape of these primary radials is some- 
thing special, rarely seen in any other genus, it being something like a heraldic 
shield, the upper part of which is produced right and left. The pointed extremi- 
ties of each join similar extremities of adjacent primary radials, and thus 
enclose the suh-cordiform inter-radials, which lie between and separate the 
primary radials. The inter-radials are, properly speaking, only two in number, 
because the third piece, although nearly of the same shape as the others, is 
joined to the two" anal pieces of the irregular side, and is partly united to 
them. Although it is probable that there are at least three ana! pieces, I 
have been able to observe only two, including that which I consider analo- 
gous to the inter-radials properly so called, on account of the imperfect state 
of the anal side of the only specimen complete enough in its other parts that 
I have had at my disposal. With the exception of the first brachial pieces, 
the pieces forming the cup are not very thick, and are easily distinguished from 
one another by well-marked sutures in the form of grooves. Their surface is 
generally smooth, judging from the external casts sent me, hut it is possible 
to see at the edges of some of the suh-radials a small number of irregular 
faintly-marked lines of growth, as Professor McCoy has correctly observed. 
Dimensions . — The only sufficiently perfect specimen, that has served 
for this description, was three and a half centimetres long; its greater 
diameter was four centimetres, and its smaller diameter three centimetres ; 
hut various fragments lead me to suppose that the calyx of this species may 
reach twice this size. 
^ [That is one side in each plate, as shown in the diagram. — T.W.E.D.] 
^ [Only one anal plate, however, in addition to the third inter-radial (azygous or radianal) plate, appears 
to have been figured in the above diagram, in which a space has been reserved below the upper extremity of the 
“ primary radial ” shown on the right hand side of the above diagram. Reference to McCoy’s, Ratte’s, and 
Etheridge’s plates confirms this supposition. — T.W.E.D.] 
