NEAL: NEEVOUS SYSTEM IN SQUALUS ACANTHIAS. 293 



DESCRIPTION OF PLATES. 



An the drawings were made with the Abbe' 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 3 (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. 



