OF THE HAND. 



317 



surface, with the trapezio-metacarpal articulation. By its inner border, with the 

 Flexor brevis pollicis. 



The Flexor Brevis Pollicis is much larger than either of the two preceding 

 muscles, beneath which it is placed. It consists of two portions, in the interval 

 between which lies the tendon of the Flexor longus pollicis. The anterior and 



Fig. 177. Muscles of the Left Hand. Palmar Surface. 



more superficial portion arises from the trapezium and outer two-thirds of -the 

 annular ligament; the deeper portion from the trapezoides, os magnum, base 

 of the third metacarpal bone, and sheath of the tendon of the Flexor carpi radialis. 

 The fleshy fibres unite to form a single muscle ; this divides into two portions, 



