344 



H. "VV. NORKIS AND SALLY P. HUGHES 



origin of the rectus lateralis (externus) muscle, is crescentric, 

 dumb-bell shaped, an anterodorsal superficial ophthalmic por- 

 tion and a posteroventral buccal portion, the two parts being 



Fig. 38 A cross-section through the roots of the left facial nerve of Mustelus 

 californicus, slightly anterior to that shown in the preceding figure. The dorsal 

 lateral-line root in its passage ventrally is seen 'straddling' (to use the expression 

 of Allis) the ventral lateral-line root. The section cuts the posterior end of the 

 buccal ganglion (gbuc.) and the anterior end of the ganglion of the ramus man- 

 dibularis externus VII (gmde.). X25. 



continuous through a narrow ganglionic neck (figs. 15 to 17, 21, 

 and 24, gos. VII, gbuc). The anterior portion, from which 

 arises the ramus ophthalmicus superficialis VII, extends forward 

 some distance as a central core in the superficial ophthalmic 



