690 l>r HARRIS H. WILDER, 



runs outward and passes within the capsule at the posterior edge of 

 its lateral wing. As it enters the capsule it sends off a small su- 

 perior branch. The main nerve runs beneath the wing but a short 

 distance, issuing soon througli a small foramen already described. It 

 is then distributed to a small portion of the front and side of the 

 lip, anterior to the distribution of the superior maxillary nerve. 



5) This nerve is formed by communicating branches of the deep 

 ophthalmic and superior maxillary nerves. Soon after its formation 

 it sends a small branch inward which anastomoses with the anterior 

 palatine branch of the facialis, which thus, at its final distribution, 

 contains trigeminus elements. The nerve then follows the edge of 

 the internasal septum, lying between the nasal mucous membrane and 

 the walls of the skull. It is accompanied here by the anterior palatine 

 branch which runs immediately below it, and by the deep ophthalmic 

 branch which lies considerably superior to it. 



It is here also intimately associated with the branches of the 

 olfactory nerve and is undoubtedly identical with the somewhat doubt- 

 ful branch which Fischer has described in Siredon, which, according 

 to his description, branches from the deep ophthalmic and anastomoses 

 with the olfactory. This is does not do in Siren at least, but pursues 

 a direct course forward among the intermaxillary glands, and finally 

 issues from the large anterior foramen in the nasal capsule, together 

 with the terminal branches of the deep ophthalmic, having a like 

 distribution to the skin of the rostrum. 



6) This nerve, near the posterior limit of the nasal cavity, curves 

 upwards and outwards in order to reach the edge of the internasal 

 septum. At this curve it receives the auxiliary branch from the 

 external nasal. 



From this point it runs in a straight line to the rostrum, where 

 its terminal fibres are distributed. 



From the above description of the nerves of the nasal region, it 

 will be noticed first that the nerve supply to this region is ex- 

 cedingly rich, and secondly that nearly every branch is focalized at 

 the rostrum or projecting portion of the upper lip. This organ must 

 be highly sensitive and serves doubtless as a special tactile appara- 

 tus to guide the animal while in the mud and dirty water at the 

 bottom of stagnant pools, 



