156 



ZOOLOGY 



SECT. 



orbit in close relation to the superficial ophthalmic branch of the 

 trigeminal, and is distributed to the lateral line and ampullary 

 canals of the snout region ; the buccal runs forwards in intimate 

 relation with the maxillary division of the trigeminal, and breaks 

 up into branches which are distributed to the sensory canals and 

 ampullae of the region of the snout ; the palatine (pi. VII, VIIp.) 

 passes to the roof of the mouth ; the main body of the nerve 

 hyomandibular nerve (hy. mnd. VII, VHhy.) then runs outwards 

 close to the edge of the hyomandibular cartilage and behind the 

 spiracle, eventually becoming distributed to the muscles between 



FlO. 833. Scyllium catulus. Dissection of the brain and spinal nerves from the dorsal 

 surface. The right eye has been removed. The cut surfaces of the cartilaginous skull and 

 spinal column are dotted. The buccal branch of the facial is not represented, cl.l cl.5, 

 branchial clefts ; ep. epiphysis ; ex. rect. posterior rectus muscle of the eye-ball ; gl. ph. 

 glossopharyngeal ; hor. can. horizontal semicircular canal ; hy. mnd. VII. hyomandibular 

 portion of the facial ; inf. obi. inferior oblique muscle ; int. rect. anterior rectus muscle ; 

 lat. vag. lateral branch of vagus ; mx. V. maxillary division of the trigeminal ; olf. cps. 

 olfactory capsule ; olf. s. olfactory sac ; oph. V. VII. superficial ophthalmic branches of 

 trigeminal and facial ; path, fourth nerve ; pi. VII. palatine branch of facial ; sp. co. spinal 

 cord ; sp, spir. spiracle ; s. rect. superior rectus muscle ; s. olb. superior oblique ; vag. 

 vagus ; vest, vestibule. (From Marshall and Hurst.) 



the spiracle and the first branchial cleft ; a small external mandi- 

 bular branch (VII e.m.) comes off from it and goes to the lateral 

 line and ampullary canals of the lower jaw. 



The eighth or auditory nerve passes directly into the internal 

 ear, and breaks up into branches for the supply of its various 

 parts. The glossopharyngeal (gl. ph., IX) perforates the posterior 

 part of the auditory region of the skull, and, after it reaches the 



