101 
use of this interval, which, as has been observed, has something similar to it in 
Poteriocrinites and Cyathocrinites, is yet unexplained. I have sometimes con- 
jectured that it may have included the opening of the oviduct. 
To the upper angles of the scapnle adhere two oblong cuneiform joints, 
forming as it were a short double arm, having sometimes the point of 
their inner angle truncated for the admission of a minute square plate. From 
the superior angle of each of the cuneiform joints proceed (Pt. 1. fig. 1.) on 
the sides approaching a series of joints forming the hand, and on the outer sides 
a finger composed of two slightly horse-shoe shaped joints, on which a double 
series of joints are arranged, bevelling off and dovetailed at their inner margin 
into each other, and thus resembling the finger joints of Encrinites moniliformis. 
Thus the series of joints forming the Hanp, (PL. v. fig. 17. to 36.) proceed 
each from the inner angle of the two cuneiform arm joints affixed to the 
scapule ; they vary in their form, the first joint being simple, convex towards 
the middle of its outer margin, slightly excavated above, to admit the next or 
second joint, which by the irregular form of its upper and lower edges resem- 
bles a double wedge, (fig. 33. to 35.) Above this two half joints are inserted, 
on which another cuneiform joint rests, sending off two fingers each like the 
first, formed of a double series of joints: 
The first joints of the hand adhere laterally at their approaching surfaces to 
each other, and are here somewhat truncated to admit the minute square plates 
mentioned before ; at their outer lateral surface they adhere firmly to the first 
Joint of the first finger, which again connects laterally with the pectoral plates. 
The Finerrs (Pt. v. fig. 37. to 51.)are formed of two series of joints, adhering 
where they dovetail laterally into each other by a muscular integument only : this 
accounts for not unfrequently meeting specimens where their series have sepa- 
rated in this part for a considerable length, and thereby neatly displayed the 
interior formation and insertion of the first tentacular joint. 
Pecrorau Puates. (PL. tv. fig. 27. to 29.) Between the scapule are inserted 
several series of small hexagonal, heptagonal, and octagonal plates, connected 
with the integument covering the abdominal cavity, so often already alluded 
to in other specimens. These I have named the pectoral plates ; they seem to 
be capable only ofa very slight muscular contraction. 
