MUSTELUS LJ;V18. lo9 



spond souiewliat to the infra- trochlear branch of tlie nasal 

 nerve of man. 



Near the anterior end of the orbit the ophthalmicus 

 profundus passes between the obliquus superior and obliquus 

 inferior muscles, near their insertions, lyi^S" ^'^ ^'^^ accustomed 

 relations, ventral to the one and dorsal to the other. Beyond 

 these muscles the nerve passes along the mesial edge of the 

 muscle Addj3, and then, when it reaches the level of the hind 

 end of the nasal chamber, pierces the cartilaginous side wall 

 of the brain case, considerably dorsal to the nasal chamber, 

 and euters the cranial cavity. There it runs forward along 

 the inner surface of the side wall of the brain case, there 

 lying directly internal to the antorbital process. Somewhat 

 anterior to that process it again pierces the cartilaginous side 

 wall of the brain case, and, issuing a second time from the 

 cranial cavity, reaches the position slightly ventro-lateral to 

 the ophthalmicus superficialis already described in describing 

 the latter nerve. In this position it passes on to the dorsal 

 surface of the nasal capsule, and toward the anterior end of 

 that capsule, after giving off a large branch, comes into 

 intimate juxtaposition with the ventral surface of the 

 ophthalmicus superficialis. Leaving that nerve, it gives off 

 a small branch, and then separates into two lar<>e branches, 

 each of which again separates into two branches. All five of 

 the terminal branches thus formed of the nerve turn down- 

 ward over the anterior end of the nasal capsule, and then 

 backward along its ventral surface. Running backward, 

 ventral to the nasal capsule, the branches of the mesial one 

 of the two large branches of the nerve gradually disappear. 

 The largest branch of the other lateral and larger portion of 

 the nerve soon pierces the ventral wall of the nasal capsule, 

 and reaches the inner surface of the capsule. There it 

 continues backward toAvard the nasal aperttire, breaking up 

 into several branches, some of which pierce the cartilage 

 again, passing outward through it to its external surface. 



The large branch given off just before the main nerve 

 comes into intimate juxtaposition with the ophthalmicus 



