BY W. J. S. McKAY. 297 



Relations. Both portions of the muscle cross the tendons 

 of insertion of the latissimus dorsi on the antoro-internal face of 

 the humerus. 



Innervation. N. musculo-cutaneus from the iv. v. vi. vii. 

 cervical nerves in both animals. 



Westlixg — Echidna : N. musculo-cutaneus from the v. et vi. 

 cervical nerves : Ornithorhynchus, N. musculo-cutaneus. (Fig. 

 17, CL). 



ECHIDXA. 



Westling describes two bellies, a smaller one springing from 

 the epicoracoid and inserted on the ulna, and a larger from the 

 coracoid, springing in common with the coraco-brachialis longus, 

 and inserted on the radius. Westling proceeds to remark that in 

 Ornithorhynchus the biceps has two bellies, and that in most 

 Saurians the biceps arises from the coracoid only and not from the 

 scapula, and is inserted on to the radius and ulna, and refers to 

 Fiirbringer's tigure of Uromastrix spinipes. 



Leche follows Westling, but says, "Nach welcher soil ei nur 

 am Radius inseriren (1)." 



MiVART says— "The biceps has but a single head, thus differing 

 from the Ornithorhynchiis [and refers to Meckel]. It is thick and 

 fleshy near its origin, but towards its insertion expands in the 

 direction of the long axis of the forearm. It arises mainly from 

 the strong tendon of the coraco-brachialis, but also in part from 

 the coracoid ; and some fibres take origin from the epicoracoid. It 

 is inserted into the radius in part, but also into the ulna as far 

 back as the coronoid process. . . . This insertion into both 

 radius and ulna takes place in the Pig (Meckel and Huxley), and 

 according to Meckel it is inserted either wholly or in part into the 

 ulna in many animals." 



Ornithorhynchus. 



Owen — "The biceps brachii arises by two heads; one arises 

 from the sternal extremity of the coracoid [epicoracoid], the other 

 also arises from the coracoid ; the common tendon is inserted into 

 the middle of the radius." 



