HEAD-MUSOLES IN GALLUS AND OTHER SAUROPSIDA. 527 



In tlie Sauropsida the mandibular myotome (after separa- 

 tion of the Ankge of the superior oblique) grows upwards to 



.J - -cona.colli. 



aur. per. Me. 



P.sup VI, 



ft.ext. 



pal pterbar 



St ernohy 

 mand my up post ny/o. 



pty pr o^quad. 



Text-figs. 21 and 22. — Sagittal sections through an embryo of 

 Alligator, slightly younger than "stage 2" of Parker. The 

 pterygoid muscle can be seen extending upwards outside the 

 pterygoid process (which has as yet no processus ascendens) of the 

 quadrate, and excluding the upper part of the mandibular myo- 

 tome from its insertion into the pterygoid process. 21 is the more 

 external. (For explanation of lettering see p. 555.) 



VOL. 51; PAUT 4. — NKW SERIES. 



40 



