Figure 1G .Dorsal view of stage "E" showing the cil- 

 iated bands. 

 Figure 17 .A reconstruction of the anatomy of a larva 

 in stage "E'J the ventral ectoderm re- 

 moved. 

 Figure 13. An outline drawing of of Fig. 17. on which 

 are indicated by lines the planes of the 

 sections shown in Figs. 10, 20, and 21. 

 Figures 10,20 and 21 .Transverse sections talten through 

 larvae in stage "E" in planes indicated 

 on Fig 18. by the lines r-s,t-u and v-w. 

 Figure 32 Reconstruction of the anatomy cf a larva 



in stage "G" .In this case as in all of the 

 other reconstructions the ventral surface 

 is up and the ventral ectoderm removed. 

 Figure 32, An outline drawing of the water vascular 



system of a larva in stage "G"seen from the 

 ventral surface. 

 Figure 33. Transverse section of stage "H't 



through the region of the stone canal. 

 Figure 34. Transverse section of a larva in stags"!!" 

 talten throng:, the stomach. 



