PLATE 4 
EXPLANATION OF FIGURE 
Figure 11 is a reconstruction similar to figures 7, 8,9, and10. This larva was 
6 mm. long. Cerebral ganglia are represented by cross-hatched lines; neural 
crest by diagonal lines, and mesoderm by stipple. The neural canal, notochord, 
alimentary canal, and sense organs are represented by lines. The gill slits are 
unshaded. All a the neural crest below the ventral border of the corneas gan- 
glia will be converted into mesenchyme or cartilages. 
