468 



WILLIAM A. HILTON 



'1^^^;^ 





10 



1% Msii 

 12 



""r 



II 



.1 



13 



Fig. 



Fig. 



Fig. 

 period. 



Fig. 

 Drawn 



Fig. 

 during 



Fig. 

 X 350. 



8 Central nervous system of A. erectus during first larval stage. X 350. 



9 Nervous system of A. erectus during the second larval period. X 350. 



10 Section through whole larva of A. erectus during the third larval 

 X 350. 



11 Central nervous system of A. erectus at about the third larval stage, 

 from a whole mount which did not show as much as some others. X 300. 



12 Longitudinal section through the central nervous system of A. erectus 

 the last larval stage. X 350. 



13 The central nervous system of the first larval stage of Ammothella. 



