FoLsou. — Development Anurida. 



PLATE 4. 



Fig. 23. Anterior aspect of a transection of germ band at mandibular segment in 



Stage 7. Tlie section being thick shows both mandibles and, behind 



them, the superlingute. X 762. 

 Fig. 24. Left aspect of embryonic head, represented as if transparent, at Stage 7. 



X480. 

 Fig. 25. Ventral aspect of lingua and first maxilla at Stage 7. X 480. 

 Fig. 26. Dorsal aspect of head of right maxilla at Stage 8. X 7(52. 

 Fig. 27. Dorsal aspect of lingua and superHnguae at Stage 7. X 762. 

 Fig. 28. Paramedian section to show the primitive cephalic ganglia at Stage 5. X 



762. 



