406 Habris Hawthorne Wilder, 



Digit II: This is the only digit not supplied with a pair of 

 these muscles, as the radial one is here wanting. Its place is, 

 however, supplied physiologically by the pronator, which is inserted 

 mainly into the base of the metacarpal of this digit upon its radial 

 side and thus acts as a strong abdnctor. The ulnar slip arises from 

 the radial portion of the distal niargin of carpale 3 and inserts 

 normally into the shaft of the metacarpal at the point given above 

 in the general sketch. 



Digit III: Furnished with a pair of muscles closely corre- 

 sponding to the type. The radial one arises from carpale 3, the 

 ulnar one in part from this and in part from carpale 4 -j- 5 and 

 from the interspace between them. 



Digit IV: Furnished with a pair of muscles closely corre- 

 sponding to the type. Both arise from carpale 4 — j— 5. 



Digit V: The radial mass is very broad. It arises from the 

 ulnar half of the margin of carpale 4 -\- 5 and inserts obliquely 

 along a line that is nearly as long as the entire shaft of the bone, 

 the radial fibers being the longest. The ulnar muscle is the most 

 eccentric in the series. It arises from the outer side of the tendon 

 of M. flexor ulnaris and inserts upon the ulnar border of the meta- 

 carpal, the area of insertion being much restricted. 



Mm. intermetacarpales (im 1 — 3). These small muscles 

 are the deepest of the entire series and, so far as location goes, 

 may be equally well ascribed to either the flexor or the extensor 

 side, although from their use as ad- and ab-ductors of the separate 

 digits they are better treated in this place, following other Short 

 muscles that are similar in function. They are in the form of thin, 

 somewhat triangulär sheets, that occupy the interdigital Spaces, and 

 may thus become partly visible by strongly separating the digits, 

 even before the removal of any of the muscles. They extend across 

 between the metacarpal bones, and may be said to arise from the 

 radial aspect of metacarpalia III — V, where they are the narrowest, 

 and to expand fan-like to broader insertions upon the ulnar margins 

 of metacarpalia II— IV. 



D. Muscles of the pelvic girdle and the proximal portioii of 



the free limb. 



1. Ventral aspect of pelvic girdle. 

 M. puboischiotibialis (pit). This is the most superficial 

 of the muscular layers covering the ventral aspect of the pelvic 



