OF THE HEAD I\ THE BATRACHIA URODEI>A. 



107 



and the prseoccipital and occipital arches. The latter is complete 

 above the brain. The second muscular segment, really the third 

 myotome developed in the 4th somite, is split in two by the 

 vagus. The first hypoglossal nerve comes out between the skull 

 and the first neural arch. 



Text-fiii. 35. 



0£. Sp."^ 



na; zpq 



poc. gt. 



Partial reconstruction of the left side of the head region of the larva shown in 

 text-fisi'. 34. Represents the same structures cut back to nearer the middle 

 line, the auditory capsule and side wall of the skull being- removed and the 

 vagus roots exposed. 



Text-fig. 36. 



f 



fac. 

 ac 



99^' 



gv 



nch. 



Kftconstraction, seen from above, of the hind region of the skull, and anterior 

 neural arches. Some roots of cranial nerves are seen on the right. 



