1889.] 



ANATOMY OF RHINOCEROS SUMATRENSIS. 



17 



Rhinoceros. 



Flex. obi. met. . . . Origin by one head from 

 flexor condyle, by a 2nd 

 head partly from olecra- 

 non and partly from 

 humerus. Ins. (l) by a 

 tendon upon pisiform ; {'!) 

 by flerihy fibres upon radial 

 side of carpus. 



Flex. int. met. ... Origin from flexor con- 

 dyle. Ins. proximal end 

 of radial metacarpal. 



Flex, '^erforatits... Origin from flexor condyle. 

 Ins. bases of 2ud phalanx 

 of all 3 digits. 



Flexor profundus. Origin from flexor condyle. 

 Ins. bases of last phalanx 

 of each digit. 



Pahnark longus (?) Present. 



Ext. met Origin. Extensor condyle 



and radius. Ins. carpal 

 end of middle metacarpal. 



Horse. 



Origin. By two heads as in 

 Ehinoceros. 2nd head 

 arises mill/ from olecra- 

 non. Insertion only on to 

 pisiform. 



The same. 



The same, allowing for 

 absence of phalanges of 

 2nd and 4th digits. 



Origin :— (1) From flexor 

 condyle ; (T) olecranon ; 

 (3) posterior surface of 

 radius. 



Absent. 



Origin only from humerus. 



Rhinoceros. 



Extensor met 



Ext. comni. digit. 



FiXt. lat. digit. .. 



Tapir. 



Origin only from humerus. 



Origin : — (1) Outer condyle ; 

 (2) head of radius; (."5) 

 fro.n middle of ulna. 



Origin from extensor con- 

 dyle and from ulna and 

 radius. Ins rtion, outer 

 digits 3 and 4. 



It will be seen from the above tabular compaTison of some of the 

 muscles of the Rhinoceros with the corresponding muscles of the 

 Horse that there are some differences, particularly iu the extensors. 



We shall now compare the myology of Rhinoceros with that of 

 Hyrax ; our comparison is not based upon a di.-section of Hyrax, 

 but upon the detailed account of the muscular anatomy of that 

 animal by Messrs. JMurie and Mivart\ 



The extensor muscles of the manus in Rhinoceros are, as in the 

 Horse, only four in number ; the corresponding muscles in Hyrax 

 appear to be as follows : — 



Rhinoceros, Horse. 



Extensor coynmunis digitorum. 

 Extensor lateralis digitorum. 

 Extensor obliquus meiacarpi. 



Extensor metacarfi. 



Hyrax. 



Extensor communis digitorum. 



Extensor ininimi digiii. 



Extensor ossis metcccarpi pollicis. 

 I Extensor carpi longior. 

 \ Extensor carpi brevior. 



PROC. ZOOL. SOC- 



' P. Z. S. 1865, p. 329. 

 -1889, No. II. 



