1867/ 



MYOLOGY OF IGUANA TUBERCULATA. 



Fig. 8. 



779 



Muscles of inside of right arm, the pectoralis and deltoid being cut short and 



reflected. 



B. Biceps. B. A. Brachialis anticus. 6'. 5.1. First, or short, part of coraeo- 

 brachialis. C.B.2. Second, or long, part of coi'aco-brachialis. D.I. First 

 part of deltoid. D. 2. Second part of deltoid. E. H. Epicoraco-humeral. 

 /. 8. Infraspinatus. P. Pectoralis. iS'. C. M. Sterno-cleido-mastoid. T. 3. 

 Third, or external humeral, head of triceps, t. Tendinous fascia of origin 

 of sterno-cleido-mastoid extending, between epicoraco-humeral and pecto- 

 ralis, backwards to the true sternum. 



Suhscapularis. This muscle is enormously developed, and is di- 

 visible into two parts (fig. 7, S. 1 and S. 2) : — 



(1) The first portion arises from the whole internal surface of 

 the coracoid and epicoracoid, the spinous process of the scapula, and 

 the membrane of each fenestra. The fibres converge, and towards 

 its insertion this portion fuses with the second part. 



(2) The second portion arises from the lower part of the internal 

 surface of the scapula and from the lower half of its posterior, or 

 axillary, margin. It becomes tendinous towards its insertion, and, 

 fusing with the first part, is attached to the ulnar tuberosity of the 

 humerus and to the capsular ligament. This muscle is shown in 

 fig. 2 (though its letter has been accidentally omitted), between Z) 2, 

 S.Mg., T. I, and the band binding down /. S. 



Internal sterno-coracoid (fig. 7, /. S. C). The specimen examined 

 by me had had the whole ventral surface of the body medianly di- 

 vided from behind forwards, so that I cannot define the inner limit 

 of this muscle. It arises, however, from the deep surface of the 

 sternum, internal to the line of its junction with the coracoid and to 

 the attachments of the ribs, and is inserted, by tendinous fibres, into 

 the deep surface of the coracoid and lower part of the epicoracoid 

 (^. e. to the deep surface of its lower spur), where it is contiguous 

 to the inferior margin of the first portion of the suhscapularis. 



External sterno-coracoid (fig. 7, E. S. C). This is a much smaller 

 muscle than the preceding, which overlaps it when the inner surface 

 of the scapular arch is looked at. It arises from the deep margin of 

 that furrow (on the outer edge of the sternum) which receives the 

 coracoid, and is inserted into the coracoid and epicoracoid, passing 

 between those bones and the tendon of the internal sterno-coracoid. 



