80 
The Five Scapute (fig. 7.) adhere to the upper edge of the pelvis, are 
thick, short, bevelled at the summit, with an excavation, and a horse-shoe 
shaped impression for the insertion of the arms. 
The pelvis and scapule (fig. 1. to 7.) are thicker near the centre than at their 
margin of adhesion, and display their muscularity in a conspicuous manner. 
Previous to the exertion of the contracting muscular power of the animal they 
are nearly smooth, sloping towards the sutures (tig. 1.22. to 24.) On contrac- 
tion, the bevelled edges become rounded, and the smooth surface undulating 
and corrugated. (fig. 3. and 6.) On still further contraction, the various 
branches of the muscles become visible, and the pelvis shows two or three se- 
ries of tubercles (fig. 1. 4. and 7.) viz. four, three, and two, in the smaller plate of 
the pelvis, and six, four, and two, on each of the two larger. In this case five or 
six tubercles are arranged in a crescent on the scapule, below the horse-shoe-like 
depression, having sometimes another similar series under them. In other speci- 
mens I have observed each tubercle in this second or lower series, assuming an 
oblong figure, (fig. 18. and 19.) and traced it until it connected with the tubercle 
above it, and forming, together with it, a single ridge, (fig. 17. 20. and 21.) thus 
displaying on each of the scapule several radiated ridges. Ina specimen in my 
possession (fig. 5.) a still greater number of tubercles are visible, which are 
irregularly arranged. 
Arms AnD fHanps.—On each of the scapule is inserted a cuneiform joint, 
forming the arm (fig. 8. and 9.) on which the two joints of the first series of the 
hand affix (fig. 10.) having each at their summit a cuneiform joint, sending 
off on the one side a finger, and on the other the second series of the hand, sur- 
mounted by another cuneiform joint supporting two fingers. 
The Fincers (fig. 1.) are formed each of two series of joints resembling 
those of Encrinites moniliformis, and sending off like them series of tentacula. 
The Inrreument over the abdominal cavity is protected by large and 
thick angular plates, and is capable of elongating itself in the centre into a pro- 
boscis, analagous to that in Actinocrinites, which will be hereafter described. 
