THE SKATE. 77 



against the outer side of the skull wall, and springing from 

 the posterior dorsal root mentioned in 186. 



191. The superior oblique muscle of the eye, passing 

 from its origin at the anterior part of the skull wall to its 

 insertion in the antero-superior region of the eye-ball. 



192. The superior rectus muscle, arising from the 

 skull wall, a little in front of the auditory capsule, and 

 passing to its insertion on the postero-superior region of the 

 eye-ball. 



193. The internal rectus, arising immediately in front 

 of the superior rectus and passing to the front part of the 

 eye-ball, beneath the superior oblique. 



194. The external rectus, arising just behind the 

 superior rectus and passing almost directly outwards to the 

 posterior region of the eye-ball. 



195. The fourth nerve (Fig. 22, IV), leaving the skull 

 by its numerous foramina, and spreading out in a fan-like 

 manner on the dorsal surface of the superior oblique 

 muscle. 



196. The third nerve (Fig. 22, 7/7), which, after leav- 

 ing the skull, sends branches to the superior (s.r) and 

 internal (i.r) recti, and then curves round the posterior 

 edge of the former : its further course will be seen at a 

 later stage ( 203). 



197. The sixth nerve (Fig. 22, VI\ leaving the skull 

 along with the fifth and seventh, and being distributed to 

 the external rectus muscle. 



XLII. Remove the superior oblique and the superior 

 and external recti. Make out 



198. The ventral ramus of the orbito-nasal nerve 

 (Figs. 22 and 27, F lb ) springing from the anterior fasciculus 

 mentioned in 186 : after leaving the skull by the trigeminal 

 foramen, it passes over the external rectus, under the 



