1885.] 



MYOLOGY OF THE WATER-OPOSSUM. 



H 



Supinator brevis. — Arises from external condyle of humerus. 

 Its upper fibres pass in a sling-like manner round head of radius, 

 whilst its lower fibres pass obliquely downwards and inwards and 

 are inserted into surface of radius external to its oblique line. 



Muscles of Hand. 



Dorsal group. — Abductor pollicis. — Arising from annular liga- 

 ment, trapezium, and scaphoid, slightly united at its origin with 

 flexor brevis pollicis ; inserted into outer side of base of first phalanx 

 of thumb. 



Abductor minimi digiti. — INIuch larger than preceding, arising by 



Fig. 1. 



S.Sp 



S.M R 



B 



I'.Mi 



C.S 



CM CO 



Myology of Water-Opossum. 



i?., rhomboideus ; S.M., serratus magnus ; 2).. deltoid ; T.Ma., teres major; 

 0./7., omo-hyoid ; Co., omo-atlantic ; S. S/>., supra-spinatus ; /.s., infra- 

 spinatus; 7/)., trapezius ; T. J//., teres minor; T;-., triceps ; i.S., levator 

 scapulae; Sb., subclavius ; C'.^f., cleido-mastoid ; CO., cleido-occipital ; 

 C'.B., coraco-bracbialis ; Hi., biceps. 



two heads from annular ligament and pisiform. Inserted into base 

 of first phalanx of minimus. 



First dorsal interosseous. — Arises from palmar surface of meta- 

 carpal of thumb. Inserted into radial side of first phalanx of index. 



Second dorsal intei-osseous. — Arises from radial side of base of 

 metacarpal of medius, and ulnar side of metacarpal of index in its 

 whole length. Arched tendon, the larger end being inserted into 

 radial side of base of first phalanx of medius, and the smaller end 

 passing on to p.ilmar surface of metacarpal of index. 



