250 Journal of Comparative Neurology. 



ering the m. cerato-hyoideus externus and the m. inter- 

 hyoideus. 



The motor component of the trigeminus goes out with 

 the mandibular trunk and innervates the masseter, temporalis, 

 and mylo-hyoid muscles. A few terminal twigs fuse with fibers 

 of the r. jugularis VII, and enter the m. inter-hyoideus. The 

 motor component of the facial nerve innervates the m. depres- 

 sor mandibulae, m. cerato-hyoideus externus, and m. inter- 

 hyoideus. 



The r. palatinus VII, near the internal nares, forms into 

 two divisions, both of which fuse with divisions of the ventral 

 terminal branch of the ophthalmicus profundus V. The r. 

 palatinus caudalis passes to the roof of the mouth by a distinct 

 foramen. It anastomoses with the second branch of the glosso- 

 pharyngeus and innervates the area laterally of that of the r. 

 palatinus. The remainder of the communis component of the 

 facialis usually becomes the r. alveolaris VII, though it may 

 sometimes form a small nerve which I have called "facialis A." 

 The r. alveolaris receives communis fibers from the glossopharyn- 

 geus and, in passing along the posterior margin of the suspen- 

 sorium, lies anteriorly of the pharyngeal evagination which 

 represents the embryonic spiracular cleft. The nerve enters a 

 canal in the mandible and anastomoses, by one division, with 

 the mandibular V. The remainder of the nerve passes out of 

 the canal dorsally of the musculature and is distributed to the 

 epithelium of the floor of the mouth anteriorly. The twig 

 called "facialis A" fuses with the r. pre-trematicus IX. It is 

 possible, and sometimes seems certain, that communis fibers of 

 the facial go to the skin over the suspensorium. 



In some instances there are small general cutaneous nerves, 

 which arise more or less independently from the Gasserian gan- 

 glion, to the skin over, and caudally of, the exit of the trigem- 

 inus from the foramen. 



The ganglia of the single glossopharyngeal and the four 

 vagus roots fuse into a ganglionic complex of which the lateralis 

 X ganglion forms the dorsal part; the glossopharyngeal, the 

 antero-ventral part ; the general cutaneous X, the postero-ven- 



