14 -LY.ACYI, The Myology of the Bell-Magpie. [.sfT'iy 



origin of the infraspinatus (57). Its fibres converge to be 

 inserted on the ulnar margin of the pneumatic fossa of the humerus 

 between the two branches of the external head of the triceps. 

 Shufeldt could divide this muscle on the American Raven into 

 two parts. In Strepera, the Australian Raven, Gymnorhina, and 

 Cr adieus this muscle does not show a distinct division into two. 



59. The serratus magnus antiais agrees with Shufeldt 's descrip- 

 tion of the muscle in the American Raven. It has three digitations, 

 arising from the second, third, and fourth dorsal ribs, and running 

 upwards to be inserted at the end of the scapula. 



60. The sub-davius arises from the space between the sternal 

 process and the coracoid, as well as from a fossa beneath the 

 coracoid. It is covered to a large extent by the pedoralis tertius 

 (51). The contraction of this muscle causes the coracoid to slide 

 along its bed upon the sternum, and holds the coracoid firmly in 

 position. 



61. The coraco-brachialis [21] is in Strepera a longer muscle 

 than in the Australian Raven. It arises from a small area on a 

 tuberosity near the base of the coracoid and passes directly up 

 parallel with the coracoid, to be inserted on the ulnar tuberosity 

 of the humerus in company with the tendon of the next- 

 mentioned muscle. 



. In the Australian Raven there is no special tuberosity for the 

 origin of this muscle. It arises in the Raven about level with the 

 anterior insertion of the previous muscle (60). Gymnorhina and 

 Cradicus agree with Strepera. 



62. The teres minor [21] arises from the anterior part of the 

 scapula. It is a " chunky " little muscle passing under the 

 scapula and behind the coracoid to join the preceding muscle, 

 the coraco-brachialis (61). These two muscles assist in the down 

 beat of the wing and in retaining the humerus in its shallow 

 glenoid cavity. 



The next four muscles (63-66) are deep muscles concerned with 

 binding the scapula to the body. 



63. The levator-scapulcB are two fleshy muscle bands arising 

 from the lateral processes of the vertebrae with free ribs. They 

 run directly backwards to be inserted in the scapula. 



64. The thoraco-scapularis is a muscle arising by three digita- 

 tions from the free rib and the first two dorsal ribs. The fibres 

 converge and pass upwards as a thin flat tendon, dividing the 

 subscapularis (65) into two, to be inserted on the lower edge of 

 the scapula. 



65. The subscapularis is an interesting muscle. It arises on the 

 under side of the scapula as two large flattened sheets, which 

 allow the tendon of the thoraco-scapularis {64) to be inserted 

 between them. These sheets converge and pass into a short, 

 strong tendon inserted into the ulnar tuberosity close to the 



