570 'Journal of Comparative Neurology and Psychology. 



the figures cartilage is shaded with oblique Hnes and the larger 

 muscles are indicated by light lines running in the direction of 

 the muscle fibers. The following letters are used in addition to 



Fig. I. Section 39. 



Fig. 2. Section 36. 



Figs, i to ii. A series of horizontal sections of the right half of the head to show the general 

 arrangement of the ner\-es. Explanation in the text. Magnification, 8.5 diameters. 



those indicating the nerves, which will be explained below: a.o., 

 aortic arches: au, auditory capsule; m.c, mouth cavity; e, eye- 

 ball or orbit; nch., notochord; o, oesophagus; r.t., respiratory 

 tube; v.^ blood vessels; th., thyroid gland. 



