MUSCLES OF THE THORACIC LIMBS. 159 
clavotrapezius (Fig. 68, @); other fibres have origin from the 
clavicle and from a raphe laterad of the clavicle which is com- 
mon to this muscle and the clavotrapezius. It passes distad 
along the cranial surface of the arm, growing narrower as 
it appreaches the convexity of the elbow. 
dnsertion.—Kight to ten millimeters from the ulna it joins 
the brachialis muscle (Fig. 79, 7) to be inserted with it by a 
flat tendon (Fig. 79, 7; Fig. 87, c) upon a rough area on the 
medial surface of the ulna just distad of the semilunar notch, 
and about midway between the dorsal and ventral borders. 
Relations. — Outer surface with the integument. Inner 
surface with the pectoralis major (Fig. 65, 7), biceps (Fig. 
77, £), lateral head of the triceps (Fig. 75, 4), acromiodeltoid 
(Fig. 75, f), and brachialis (Fig. 80, 2). Medial border with 
the pectoantibrachialis (Fig. 65, #). Lateral border free 
except near the insertion, where it is in relation with the 
brachialis. 
Action.—Flexor of the antibrachium. 
M. supraspinatus (Fig. 75, @) occupies the whole of the 
supraspinatus fossa of the scapula. It is covered by strong 
fascia which stretches from the free edge of the spine to the 
coracoid border of the scapula and to the coracoid half of its 
vertebral border. 
Origin (Fig. 76, 4) by fleshy fibres from the whole surface 
of the supraspinatus fossa, from the above-mentioned fascia, 
and from the subscapularis (Fig. 77, @) craniad of the coracoid 
border of the scapula. 
Insertion (Fig. 83, @).—It passes over the capsule of the 
shoulder-joint, to which it is closely attached, and is inserted 
into the free border of the great tuberosity ventrad (or proxi- 
mad) of the fossa for the infraspinatus (Fig. 83, ¢). 
Relations.—Outer surface with the spinotrapezius (Fig. 
68, 7), acromiotrapezius (Fig. 68, ”), levator scapule ventralis 
(Fig. 68, /f), clavotrapezius (Fig. 68, @), and cleidomastoid 
(Fig. 65, 2). Inner surface with the scapula. The distal end 
of the coracoid border is closely related to the pectoralis minor 
(Fig. 79, f). The glenoid border is related to the origin of 
the deltoidei. 
