2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 80 



DESCRIPTION OF THE SPECIMENS 



Pan sp. — Johns Hopkins Anat. No. 38, male, with humeral length 

 of 222 mm. ; right side. 



M. hice'ps hrachii^ capita longuin et hreve. — The caput longum 

 arose from the supraglenoid tuberosity of the scapula as usual and 

 passed over the bicipital groove, which is very deep in the chimpan- 

 zee. There was also an accessory, weaker head from the capsule 

 of the joint. These two heads fused some 60 mm. below the head of 

 the humerus. Caput breve, of about equal mass but broader than 

 caput longum, arose with the coracobrachialis from the coracoid 

 process. The two biceps divisions, longum and breve, fused some 70 

 mm. from insertion upon the radial bicipital process. The terminal 

 tendon was about 25 mm. in length. There was quite a well-marked 

 lacertus fibrosus. 



M. coracohi'achialis, partes supe^'ficialis et media. — The anomalous 

 superficial portion took origin in common with, and upon the medial 

 side of, the short biceps origin from the coracoid. It continued en- 

 tirely superficial to all nerves and muscles of the brachium, except the 

 dorsoepitrochlearis, to its insertion upon the medial epicondyle. It 

 was slender but sharply defined, the distal half being nonmuscular 

 and weakly tendinous. The musculocutaneous nerve passed between 

 it and the coracobrachialis medius. The latter muscle constituted at 

 first a deeper, broader layer of the common coracoid tendon. The 

 most proximal point at which its fibers inserted upon the humerus 

 was 10 mm. above the most distal part of the deltoid, and 15 mm. 

 below the latissimus tendon ; so no part of it could be considered as 

 representing a coracobrachialis profundus (brevis). Insertion thence 

 continued for 70 mm., or to a point 60 mm. above the condyle. 



M. hrachialis. — The medial belly of this muscle was partly divisible 

 from the lateral along the line shown in Plate 1. The medial had 

 the more extensive origin from the distal half of the humerus and 

 quite to the epicondyle, and the insertion was broad and tendinous 

 into the fossa upon the ulna just distal to the coronoid process. The 

 partially separable lateral portion of the brachialis had a shorter 

 origin adjoining and partly surrounding the deltoid insertion, the 

 muscle beginning farther proximally on the lateral than it did on 

 the medial side of the deltoid insertion. Most of this division was 

 situated lateral to the biceps, but distally it twisted to the rear of the 

 latter, the fibers being pennated upon a narrow, tendinous band, 

 which fused with the anterior border of the main insertion of the 

 brachialis medialis. 



M. epitrochleo-anconeus. — This slip does not belong with the 

 brachial flexors, for it is innervated by the ulnar nerve, as we have 



