COMMON CROSSBILL. 23 



Fig. 4. Head viewed from behind : a, right temporal 

 muscle ; 5, great pyramidal muscle. 



5. Lower jaw, side view : a, cavity for articulation ; 



5, J, coronoid processes. 



6. Tongue seen from above : #, horny scoop ; &, #, 



extensor muscles. 



7. Tongue, side view : a, horny scoop ; 5, extensor 



muscles ; (?, flexor muscle. 



