Fig. 13. Head of a larva about the same age as fig. 12, ventral aspect.
Fig. 14. Side view of a larva about 15 millims. long, five days after hatching.
Fig. 15. Head of a larva 23 millims. in length.
Fig. 16. Tail of a larva 11 centims. in length.
Fig. 17. Transverse section through the egg-membranes of a just-laid ovum.
We are indebted to Professor W. K. Parker for figs. 12, 14 and 15.
Figs. 18-22. Transverse sections of embryo on the third day after impregnation.
Fig. 18. Through head, shewing the medullary keel.
Fig. 19. Through anterior part of trunk.