PLATE 3 



EXPLANATION OF FIGURES 



11 Section through the caudal region of the embryo shown in figure 5. 



12 and 13 Sections of the embryo shown in figure 6 through the regions ab 

 and cd, respectively. 



14, 15, and 16 Sections of the larva shown in figure 7 through the regions ef, 

 cd, and ab, respectively. 



17 Section of the larva shown in figure 8 through the region ab. 



18 Section of a larva 286.5 hours old. 



132 



