A IT r\ nix. ;.C. 



Their form sonu \\ hat resembles v kes 



place in the quadruped, at least in th<>M- of \\hich 

 the uses are similar, as the \ I IB, and 



F the antt i! I their arti- 



culations in part alike, although not in all of 

 them. '1 he articulation of the lower jaw, of the 

 carpus, metacarpus, and li; are exceptions, 



The articulation of the loucr ja\\ i.s not by simple 

 contact either single or double, joint d l 

 sular ligament, as in the quadruped; but by a 

 very thick intermediate substance of the liga- 

 mentous kind, so interwoven that it> parts i 

 on each other, in the interstices of which i.s an oil. 

 This thick matted .substance may answer the same 

 purpose as the double joint in the quadruped. 



The two fins are analogous to the anterior ex- 

 tremitics of the quadruped, and are also some- 

 what similar in construction. A fin is composed 

 of a scapula, os humeri, ulna, radius, carpus, and 

 metacarpus, in which last may be included the 

 fingers, because the number of bones are those 

 v, hich might be called lingers, though they are 

 not separated, but included in one general c<> 

 ing with the metacarpus. They have nothing 

 analogous to the thumb, and the number of bones 

 in each is different : iu the fore-J 

 live bones; in the middle and ring-linger SCMII. 

 and in the little linger four. The articulation of 

 the carpus, metacarpus, and fingers, is diflV 

 from that of the quadruped, n .j by capsu- 



lar ligament, but by intermediate cartilages COO- 

 mrted to each bone. These cartilage* between the 



