NEAL: NERVOUS SYSTEM IN SQUALUS ACANTHIAS. 293 
DESCRIPTION OF PLATES, 
All the drawings were made with the Abbé camera lucida. Figure 40 (Plate 6) 
is, however, a reconstruction from sections and dissected specimens. ‘The Figures 
of Plates 8 and 9, with the exception of Figures 61 and 65, are also reconstructions 
from several sections. In sagittal sections, the embryo is always viewed from the 
right side. In cross sections, it is the posterior face of the section that is shown, so 
that right in the figure corresponds to right in the section. In frontal sections, the 
dorsal face is shown, so that right in the figure here also corresponds with right in 
the section. Only Figures 2 and 8 (Plate 1) represent embryos viewed from the 
ventral side, so that what appears on the left side in these two figures is really on 
the right side of the embryo. The cells of the neural crest are in all cases colored 
blue. 
