NEW SPECIES OF PARADOXURUS. 



83 



illustrate the structure required for a plantigrade and climbing action, as 

 compared with a digitigrade one. 



The animals are as nearly as possible of an equal mean height: but 

 the length of the corresponding bones is far from equal. The Catarse 

 moves solely on his fingers by which means the length of his metacarpal 

 bones and of his wrist are added to his height. The Muchabha walks 

 entirely on his hands and wrist, being thus deprived of his carpus and 

 metacarpus as a part of his stature from the ground. But he is compen- 

 sated for this by an increased length of humerus and forearm nearly 

 amounting to the length of the metacarpus which is added to these bones 

 in composing the height of the Catarse. The centre metacarpal bone of 

 the Catarse is one inch long : His humerus half an inch shorter than that of 

 the Muchabha, and his radius (the true forearm) f of an inch shorter than 

 that of the other animal. The humerus of the plantigrade animal is 

 strongly marked with a large ridge for the insertion of a pectoral muscle 

 which rises from the whole length of the sternum; is furnished with broad 

 condyles for the origin of the muscles of the hand and fingers; and has an 

 extensive surface for articulation with the scapula. All these signs indi- 

 cate free action of the arm on the trunk, with extensive motion of the hand 

 and wrist. The humerus of the digitigrade animal, compared with the 

 above, is weak and short; is not so prominently marked with ridges; 

 its condyles scarce project beyond the articulating surface or trachlea; 

 and it shews a limited surface for articulation with the scapula. These 

 marks attest a more limited power of arm and hand, and a less free 

 motion of the extremity on the trunk. The radius in the Muchabha 

 is much stronger and | of an inch longer than in the Catarse : its arti- 

 culating surface which enters into the composition of the elbow joint, 

 is twice as large as that of the other : its rotatory motion on the ulna 

 is much more free and extensive, enabling the animal to bring the hand 

 from the state of pronation freely round to that of semi-supination ; 



