42 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. XIV. 



median head which in Didelphis and many other marsupials is united 

 with the lateral head near its origin. 



Anconeus. Origin from the inner condyle of the humerus. In- 

 sertion on the inner angle of the olecranon process entad of the epitroch- 

 learis. A small muscle connected on its lower side by a tendinous raphe 

 with the extensor carpi ulnaris and on its upper side slightly connected 

 with the median head of the triceps. 



Pronator teres. Has origin as a thick fleshy bundle from the posterior 

 side of the inner condyle of the humerus and the epicondylar ridge. 

 Insertion by broad aponeurosis on the middle third of the front of the 

 radius. 



Flexor carpi radialis. Origin from the inner humeral condyle and 

 the septa connecting with the pronator teres between which and the 

 palmaris longus it lies. Its long slender tendon passes over the extremity 

 of the radius and thence over the scaphoid to insertion at the bases of 

 the second and third metacarpals. 1 



Palmaris longus. Origin from the septa between it and the flexor 

 carpi ulnaris, the flexor carpi radialis, and the digital flexors and by a 

 few fibers from the inner condyle of the humerus. It covers the digital 

 flexors almost completely and lies between the flexor carpi ulnaris and 

 the flexor carpi radialis. 



In the single specimen dissected it was divided into two parts. The 

 superficial one (palmaris accessorius?) sends its tendon beside that of the 

 flexor carpi ulnaris to a slight attachment on the inner side of the fascia 

 on the pisiform bone and thence superficial to or partly attached to the 

 flat transverse ligament of the wrist which extends across the wrist from 

 the pisiform to the base of the first metacarpal. Above this transverse 

 ligament it extends into the palmar fascia. The deeper division sends 

 its tendon bound with its fellow to the transverse ligament where the 

 two separate and the second dips beneath the ligament to reappear in 

 the facia and send aponeurotic branches to the extremities of the second, 

 third, and fourth digits. The fleshy parts of the two divisions are 

 distinct for about one-half their length. 



Flexor carpi ulnaris. Origin from the inner condyle of the humerus, 

 from the septa between it and the palmaris longus, the extensor digitorum 

 communis, and the anconeus, and from the outer angle of the olecranon 

 opposite the insertion of the epitrochlearis. Insertion on the end of the 

 pisiform bone. A broad fan-shaped muscle with two sets of fibers con- 

 verging toward its tendon which extends a short distance into its fleshy 



1 This is also the case in Didelphis, although Coues states that the insertion is on 

 the first metacarpal; Cunningham (1882, p. 17) found a similar disposition in Pha- 

 langer maculata. 



