BY W. J. S. McKAY. 301 



Origin (c) J/, epicoraco-hrachialis. — This muscle arises by 

 flesliy fibres from the outer two-thirds of the dorsal surface of the 

 epicoracoid, and by a few fibres from the ligament which binds the 

 antero-exterual angle of this bone to the dorsal surface of the 

 interclavicle ; also by some fibres from the coracoid adjoining the 

 coraco-epicoracoid arthrodia. 



Insertion. Running outwards and posterior, the muscle 

 approaches the lesser tuberosity. A small fleshy belly with a 

 well marked tendon is differentiated from the main mass of the 

 muscle, and is inserted on the summit of the sesamoid bone in 

 close relation with the tendon of the subscapularis. The remainder 

 of the muscle now in part coalesces with the coraco-brachialis 

 brevis, and in part is inserted by a distinct tendon on the antero- 

 internal face of the lesser tuberosity, immediately adjoining the 

 sesamoid bone, the insertion being surrounded by the subscapularis, 

 teres major, and coraco-brachialis brevis ; the latter muscle hiding 

 the insertion from view. 



Innervation. Echidna: Mm. coraco-brachialis longus et 

 brevis, N. musculo-cutaneus ; M. epicoraco-brachialis, from the 

 cord formed by the iv., v., vi. and vii. cervical nerves, from which 

 the musculo-cutaneus also springs. Ornitliorhynchus: Mm. coraco- 

 brachialis longus et brevis, N. musculo-cutaneus (in two divisions); 

 M. epicoraco-brachialis, from the N. musculo-cutaneus, and from 

 a cord formed from the iv., v. and vi. cervical nerves. 



W'ESTLisci— Echidna : Mm. coraco-brachialis longus et brevis, 

 N. musculo-cutaneus. " Der mit dem M. coraco-brachialis nahft 

 vei'bundene M. epicoraco-brachialis wird nicht direct vom N. 

 musculo-cutaneus, sondern von einem Nerven aus denselben Cer- 

 vicalnerven wie dieser, innervirt." 



WESTLiNGin Ornithorhynchus found the biceps, coraco-brachialis, 

 and epicoraco-brachialis supplied by the musculo-cutaneus nerve. 



Echidna. 

 Westling says — "The M. coraco-brachialis is well developed and 

 can easily be divided into three portions at its insertion, but it is 

 more or less fused at its origin." The parts are — (1) M. coraco- 

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