53 
rise to a further subdivision, This I shall call the first cuneiform joint of the 
hand, designating the lateral branch which proceeds from it, as the first finger, 
and the continuation of the main series of Joints, as the second series of the hand 
joints. This second series, consisting of about twelve joints, terminates bya 
cuneiform joint (the second cuneiform joint of the hand) which gives rise to the ` 
second and third finger. Each of the fingers with its tentacula, bears a close 
resemblance to the vane of a quill, becoming at its superior extremity highly 
muscular. : ۱ 
The Joints of the HAND and Fincers exactly resemble those of the arms, 
only that they become gradually smaller as they approach to the point of the 
fingers, and send off, like them, tentacula from the alternate sides. 
The Tenracuta. (Pr. xı. fig. b. to 7. and 25.) The tentacular series of 
the arms, hands, and fingers, near the cuneiform joints in full grown specimens, 
consist of about twenty Joints gradually tapering to a point, but decreasing in 
number and size near the apex of the finger, where they are formed of only one 
or two joints terminating in muscular undeveloped points; proofs of their con- 
tinuing growth through the whole life of the animal, and of their possessing 5 
greater power ofaction at these extremities. The joints of the tentacula are 
nearly horse-shoe shaped, having the side where their series folds upwards 
somewhat compressed, and less protruding. 
The circumference of each tentacular joint, but particularly of those to- 
wards the point of a series (Pr. m. fig. 5. and 25.) is smaller, or contracted 
near the base; an admirable contrivance to assist motion, and also contributing 
much to give this part of the animal an elegant and finished appearance. The 
articulating surfaces present transverse ridges, pierced in the centre by the 
canal of the nourishing vessel. | 
The PLATED ÍNTEGUMENT. (Pr. 11. fig.S. and 9.) The sides of the second 
costal joints and scapulz are tied together by an integument, strengthened and 
protected externally by numerous calcareous angular plates, which extend over 
the funnel-shaped abdominal cavity, having in its centre, probably, the minute 
aperture forming the mouth, which in the prepni shrivelled -state of this part 
in the late Mr. Toniw's specimen, it was impossible to ascertain. : When 
the animal was alive, this integument, probably, was capable of having its cen- 
tral part elongated and protruded by the action of its muscles, so as to form a 
