Fig. A. Surface view of blastoderm of Pristiurus hardened in chromic acid.
Fig. B. Surface view of fresh blastoderm of Pristiurus.
Figs. C, D, E, and F. Pristiurus embryos hardened in chromic acid.
Fig. G. Torpedo embryo viewed as a transparent object.
Figs. H, I. Pristiurus embryos viewed as transparent objects.
Fig. K. Pristiurus embryo hardened in chromic acid.
The remainder of the figures are representations of embryos of Scyllium
canicula hardened in chromic acid. In every case, with the exception of the
figures marked P and Q, two representations of the same embryo are given;
one from the side and one from the under surface.