The appendicular muscles of Necturus maculosus. 395 



the latter upon the lateral (outer) aspect. The two thus correspond 

 in general position to Mm. biceps bracliii and brachialis anterior 

 of higher animals, and may be homologous with these, wholly or 

 in part. 



The coracobrachialis longus arises from the posterior tuberosity 

 of the coracoid, medial to and in contact with M. anconeus cora- 

 coideus, but the two are wholly distinct. Proximally it is also in 

 contact with M. coracobrachialis brevis, the origins of the two 

 muscles being along the same margin and close to one another. The 

 muscle inserts into the distal half of the shaft of the humerus, 

 above the infernal condyle. 



M. coracobrachialis brevis (ebb). This is a very deep 

 muscle, almost entirely covered by others. It lies between the 

 supracoraeoideus on the lateral, and the coracobrachialis longus on 

 the medial, side. It is in the form of a small triangulär sheet, and 

 Covers an area that includes about the proximal third of the humerus, 

 It arises, in contact with the foregoing muscle, from the posterior 

 margin and tuberosity of the coracoid, the two lines of origin being 

 parallel though not eoineident. From this origin the fibers converge 

 to their insertion along the medial aspect of the proximal third of 

 the shaft of the humerus. 



M. scapulohumeralis (sh). This is a band-like muscle, 

 passing obliquely from the posterior margin of the scapular region, 

 between Mm. anconeus coraeoideus and anconeus scapularis, to the 

 humerus. It arises from the margin of the deep sinus between the 

 scapula and the tuberosity of the coracoid, and includes a small 

 portion of the osseous scapula as well as the adjacent cartilage. It 

 inserts along a line which runs lengthwise along the medial side 

 of the shaft of the humerus and includes approximately the middle 

 third of the osseous shaft of that bone. 



M. humeroantebrachialis (ha). This muscle lies along the 

 flexor side of the upper arm and, while seen superficial ly from the 

 lateral aspect, is equally well seen from the medial after the rempval 

 of the two coracobrachiales ; in fact. the origin and insertion are 

 better shown from the latter aspect. It arises from the crista 

 lateralis of the humerus along its distal aspect, and extends along 

 the entire shaft of the humerus. Crossing the angle of the elbow 

 this muscle enters the antebrachial region on the radial edge 

 between the flexor and extensor masses, and inserts by a flattened 

 tendon into the lateral (radial) edge of the radius at the point 



