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 by a 

 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. 



The JOINTS of the HAND and FINGERS 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 TENTACULA. (Pi,, n. fig. 5. 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 a 

 greater power of action 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 (?L. n. 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 iu the centre by the 

 canal of the nourishing vessel. 



The PLATED INTEGUMENT. (PL. n. fig. 8. and 9.) The sides of the second 

 costal joints and scapulae 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 present shrivelled state of this part 

 in the late Mr. TOBIN'S specimen, it was impossible to ascertain. When 

 the animal was alive, this integument, probably, was capable of having its cen- 

 tsal part elongated and protruded by the action of its muscles, so as to form a 



