1883.] AiVAlOMY OF PHCENICOPTERUS. 643 



internul deltoid and biceps, to be inserted into the inner side of tlie 

 humerus ; and to this aponeurosis are attached the remaining fibres 

 of the pectoraUs. 



15. The second pectoral occupies about three quarters of the 

 ventral face of the sternum ; it also arises from the proximal half of 

 the coracoid, and from nearly the whole of the coraco-clavicular 

 membrane. Its tendon passes as usual over the scapula to go to 

 the lesser tuberosity of the humerus, at the top of the deltoid ridge. 



16. The third pectoral is relatively small ; it arises from the 

 lower third of the posterior margin of the coracoid, and passes to 

 the tip of the great tuberosity of the humerus. 



1 7. The biceps arises by two heads — a long tendon from the head 

 of the coracoid, and a fleshy head from the lower surface of the 

 pectoral aponeurosis. 



18. The supraspinatus arises from the anterior half of the ventral 

 border of the scapula, and is attached to the great tuberosity of the 

 humerus, just anteriorly to the teuton oi the pectoralis tertius. 



19. The suhscapularis arises from the anterior half of the deep 

 surface of the scapula, being inserted into the great tuberosity of the 

 humerus below the tendons of the third pectoral and supraspinatus. 



20. The extensor carpi radialis longus arises by fleshy fibres 

 from the ridge above the outer condyle of the humerus, and forms 

 a short fleshy belly, which joins a long tendon, passing first over a 

 groove in the distal head of the radius, and then over the middle 

 of three grooves on the face of the radial carpal, to be finally inserted 

 into the tuberosity of the thumb metacarpal. 



21. The extensor carpi radialis brevis arises by a short tendon 

 from the outer condyle of the humerus ; its short belly is attached 

 to the aponeurosis covering the preceding muscle, and its tendoa 

 runs below the long extensor tendon to the thumb metacarpal. 



22. The abductor pollicis arises by three slips — the first from the 

 interosseous border of the radius for about a third of its length, 

 beginning near the bicipital tuberosity ; the second from the upper 

 surface of the ulna, just beneath the head of the radius ; and the 

 third from a ridge on the ulna, just distal to the ulnar tendon of 

 the biceps. The second and third slips unite before joining the first. 



The tendon curves round to the outer side of the radius, and 

 passes through the outer of three grooves on the radial carpal bone, 

 to be inserted on the great tuberosity of the thumb metacarpal, 

 below and external to the radial extensor of the carpus. 



23. The extensor carpi ulnaris arises from the outer surface of 

 the outer condyle of the humerus, superficially to all the other 

 murcles which arise there; it is also attached to the outer side of 

 the ulna. The belly is small, and the long tendon passes through a 

 separate groove in the outer side of the ulna to the outer side of the 

 second metacarpal. 



24. The adductor manus arises from the fascia on the outer side 

 of the head of the ulna, and passes to the inner edge of the third 

 metarcarpal. 



25. lihe pronator quadratus arises from the inner (palmar) surface 



