523 



Oz Av. 



25. Supinator radii longus? 1*75 



Origin ; from the fascial covering of the outer condyle. 

 Insertion ; into the tendon of (26) at the wrist. 



1ST. B. — This muscle acts chiefly as a tensor fasciae, but is, no doubt, 

 the representative of the sup. rad. longus. 



26. Extensor carpi radialis (Fig. 37, a), 37*5 



Fig 37. 



Left Fore Arm. 



Origin ; from the outer condyle. 



Insertion;, into the near end of the metacarpal of the middle finger. 

 jNT- B. — This muscle receives at the bend of the wrist the tendon of 



the supinator longus, 



27. Extensor digitorum longus (Fig. 37, b), 13*5 



Inserted into the near end of the first phalanx of the middle finger. 



28. Extensor minimi digiti (Fig. 37, e), 6-0 



Origin ; from the outer condyle, and from the tendinous expansion 

 of the interosseous septum from the outer condyle to the wrist. 



Insertion ; into the outer side of the first phalanx of the outer finger, 

 with a tendinous slip to the metacarpal of the middle finger. 



29. Extensor carpi ulnar is? * 27'5 



Origin; from the outer condyle. 



Insertion ; into the sesamoid bone outside the base of the metacarpal 

 of the outer finger. 



N. B — I am almost certain that this muscle is the extensor ulnaris, 

 although, owing to the arrangement described in (22), it acts as a flexor. 

 The combined actions of the ulnar flexor and extensor would be to ab- 

 duct the little finger — an action which would be of great use to the 

 Ehinoceros when running on soft ground. 



30. Extensor ossis metacarpi pollicis (Fig. 37, c), .... 4*5 

 Origin ; from the anterior half of the radius and ulna, and from the 



interosseous septum. 



Insertion ; its tendon crosses the back of the wrist, binding down 

 the tendons of the radial extensor, and is inserted into the outer side of 

 the near end of the metacarpal of the inner finger. 



