334 



ELEMENTARY AM A TOMY. 



[LESS. 



Anconeus. This muscle, which in man seems to be but a 

 small part of the triceps, may be a very large and very dis- 

 tinct muscle, as in Dasypus and Phoca. 



Extensor communis digitorum. This is exceptionally dis- 

 tinct in man, being often (as e.g. already in Nycticebus] 

 blended with one or more other extensors. It may be so 

 diminished and short as to extend only from the carpus to the 

 digits, as e.g. in Igtiana and Chameleo. 



FIG. 302. RADIAL SIDE OF RIGHT ARM OF PARSON'S CHAMELEON. 

 A 3 , adductor digiti tertii; A*, adductor digit! quarti ; B, biceps ; B r , B 2 , B 3 , ex- 

 tensores phalangorum ; E 3 , E 4 , E$, extensores metacarporum ; ERL, ex- 

 tensor radialis longior ; FR, flexor radialis ; MP t extensor metacarpi pollicis ; 

 PT, pronator teres ; SL, supinator longus. 



Extensor minimi digiti. This extensor, which may be 

 absent, may also be present where we might hardly expect 

 to find it. Thus it may be present in forms in which the 

 digitus minimus is entirely absent, e.g. the Horse. This fact 

 is less remarkable, however, when it is recollected that the 



