82 PALEONTOLOGY OF NEW-YORK. 
Fig. 1 a. A nearly perfect individual of this species, with portions of the fingers and several inches of 
the column attached. The column, in its different parts, shows the structure which the other 
fragments of columns present. 
The body is composed of plates arranged as follows : 
Fig. 1 8. 8. Pelvis, composed of five small pentagonal plates. 
F. First costal plates five, heptagonal, resting upon the upper and inner edges of the pelvic 
a 
plates. 
Second costal plates five, hexagonal, resting upon the upper edges of the costal plates. 
7 
H. Scapulars five, hexagonal, and resting directly upon the last. 
a. Intercostal plate. 
I. 
Double interscapular plates. 
The intercostal plate supports upon its upper lateral edges a pair of interscapular 
plates, which are in turn succeeded by two other pairs of similar plates; the last pair 
truncated on their upper angles, and more deeply excavated between, supporting on the 
upper and inner lateral edges a small quadrangular plate, and upon the truncated upper 
edges a pair of larger quadrangular plates. 
k. Brachial plates. Each of the scapulars is surmounted by a hexagonal brachial or arm- 
plate, which supports a double cuneiform arm-joint &, from which proceed the hands 
and fingers M, N. 
Fig. 1c. Part of one of the tentaculated fingers of this species. The tentacula are long, and not jointed ; 
the joints of the fingers are cuneiform, the tentacula being attached to the broader side of 
each joint. 
Fig. 1 d. A part of one of the fingers magnified, showing the tentacula attached to the broader side of 
the plate. 
Fig. 1 e. A fragment of a small column. ff The same enlarged, showing characters precisely similar 
to the fragments of larger columns. 
Fig. 1 g. A column of large size; the upper part showing the larger thick plates, which are nodulose 
on their margins, alternating with three thinner plates : lower down the number of inter- 
mediate plates becomes four, and below this five, when the central one becomes thicker and 
broader, the edges projecting beyond the others. 
Fig. 1 4. A fragment of a small column; the surface worn nearly smooth, and presenting only the 
points of attachment of the side-arms on the thicker joints. 
Fig. 1 2 A small column; the larger joints unusually projecting, and their edges elevated. 
Fig. 1 &, 1, m. Fragments of columns from different parts, showing the alternation of larger and smaller 
plates, points of attachment for side-arms, and the weathered surface exhibiting the serrated 
appearance of the edges of the plates. 
Fig. 1 2, 0. Specimens showing the character and aspect of fragments of different parts of the column. 
In some portions there are six, seven, and eight intermediate plates, the central ones usually 
extending a little beyond the others, and showing a nodulose margin. 
Fig. 1 p. Ends of the plates of the columns, showing a striated surface. 
This column, though so variable, is still so different from the columns of other species, 
that there will be no difficulty in recognizing the species even from small fragments. 
