MtJSTELUS L/EVIS. l7o 



opposite side, though this could not be definitely established, 

 my sections being of one half of the head only. 



The dorsal branch given off by the masillaris at the same 

 time as the above-described ventral one passes outward and for- 

 ward dorsal, and hence internal, to the buccalis, and separates 

 into two parts which accompany the two branches of the 

 buccalis sent, the one to organs 44 and 45 iufra-orbital, 

 and the other to organs 42 and 43, these four organs lying 

 in the bend of the infra-orbital canal, just distal to the 

 anastomosis with the distal end of the supra-orbital canal. 

 These two branches of the maxillaris continue forward and 

 mesially beyond the distal ends of the two buccal branches 

 they at first accompany, and reach the ventral surface of the 

 nasal capsule, in the region adjoining that part of the infra- 

 orbital canal that lies posterior to the nasal aperture. A 

 branch is here sent, from the mesial one of the two nerves, 

 to accompany the branch of the buccalis that goes to organs 

 40 and 41 infra-orbital, the remaining portions of both nerves 

 continuing forward, internal to the infra-orbital canal, toward 

 the hind end of the nasal aperture. The branch that at first 

 accompanied the buccal nerve to organs 42 and 43 infra- 

 orbital, here turns dorsally through one of the slit-like 

 foramina or imperfections in the ventral floor of the nasal 

 capsule, and, entering that capsule, sends one branch forward 

 and mesially, and another forward and laterally', along the 

 ventral surface of the nasal sac. How far forward these 

 branches extended could not be determined. 



The main ravnus maxillaris, after giving off the branches 

 above described, follows the course of the infra-orbital canal, 

 and passes, with it, mesial to the nasal aperture, here lying 

 always dorso-mesial to the canal and mesial to the buccalis. 

 Several branches here arise from the maxillaris, some running- 

 forward and mesially, and others forward and laterally, the 

 latter passing internal, that is, dorsal, to the buccalis. One 

 of these latter branches turns upward into the nasal capsule, 

 and could be traced forward a certain distance, ventral to 

 the mesial portion of the nasal sac. It was then lost, but 



