xra 



PHYLUM CHORDATA 



267 



elevators which raise, and depressors which lower, a part, such as 

 the lower jaw. The names of the muscles may have reference to 

 their position, e.g. pectoralis (pet.), the principal muscle of the chest ; 



s ; ins. ten. inscriptio tendinea 



alb. linea alba 



xiphisternum, 



tbj|| k - 



/. W. UbioBbula ; 



