168 DR. R. W. SHUFELDT ON [Apr. 1, 



and it agrees with all these forms in possessing only its coracoidal 

 head. 



32. Coraco-brachialis brevis. — This is one of the deep muscles of 

 the shoulder-girdle found upon the anterior aspect of the chest, and 

 is here very well developed. It arises from the outer surface of the 

 coracoid, between the rounded, posterior angle of that bone to a 

 point anteriorly next to the origin of tlie teres minor. Its area of 

 origin is luniform, the concavity being towards the humerus ; and 

 agreeing in form, posteriorly, with the coracoid, which in this 

 locality it nearly covers. Its fibres converge as they pass towards 

 the humerus, upon which bone the muscle is inserted, the insertion 

 being upon a line extending from the head of the bone to a point at 

 the junction of upper and middle thirds, on its anterior surface : the 

 coraco-brachialis brevis also makes a partial insertion into the cap- 

 sule of the shoulder-joint. 



Posteriorly, this muscle is firmly overlapped by the thin, flat 

 tendon of the biceps, while more anteriorly some of the superficial 

 muscles cross it to the humerus. 



33. Coraco-brachialis longus. — This is a very differently charac- 

 terized muscle from the one I have just described, it being long and 

 slender, passing parallel to the humerus for its entire length. It 

 arises, upon either side, from the posterior rounded angle of the 

 coracoid, making slight encroachment upon the adjacent posterior 

 surface of the bone. From this origin this long and fleshy muscle 

 goes directly to the internal condyle of the humerus, into which it 

 inserts itself: its insertion also extends slightly up the shaft of the 

 bone, while its fascia merges with the fascia of the shoulder-joint. 



Sanders, Fiirbringer, and Hoffmann all adopt the same names for 

 these muscles as I have given them here, the first-named authority 

 using them in the case of Liolepis belli as early as 1872. Both the 

 coraco-brachialis brevis and longus are invariably present, so far as I 

 am aware, in all true Lizards. 



34. Brachialis anticus. — Comparatively larger than we find it in 

 many Vertebrates, this muscle becomes one of the important ones of 

 the arm, being even larger than the biceps. It arises, somewhat 

 tendinous, from the entire antero-external aspect of the shaft of the 

 humerus, from tuberosity to condylar extremity, being intimately 

 associated with the triceps upon its inner side, and in contact with 

 the biceps externally. Passing between the muscles of the forearm 

 in company with the tendon of the biceps, it inserts itself, tendinous, 

 into the proximal extremities of the radius and ulna, upon their 

 anterior surfaces, being largely covered by the insertional tendon of 

 the biceps in front. 



Fiirbringer terms this muscle the '' humero-antebrachialis inferior," 

 a name also adopted by Hoifniann ; it being the brachialis anticus of 

 Mivart and the brachialis internus of Riidinger. It generally inserts 

 itself into both bones of the forearm, but Mivart found that in 

 Chamceleon parsonii this muscle inserted itself only into the ulna. 



35. Triceps. — This thick and powerful muscle at the back of the 

 arm, here in our present subject exhibits four points of origin, viz. : — 



[22J 



