CEANIAL NERVES OF CAECILIANS 517 



3. The ramus maxillaris V 



The ramus maxillaris lea'ves the anterior end of the Gasserian 

 ganglion at its lateral ventral border (fig. 23, mx.), and passes 

 anteriorly and ventrally between the temporal and masseter 

 muscles (figs. 22, 21). Halving passed through the muscles it 

 divides into medial and lateral branches (fig. 20, inx.l, mx.2). 

 Shortly after this division the medial branch unites with a lateral 

 division of the ramus palatinus VII (fig. 16, mx.l + paL2) and 

 at about the same place gives off a. small branch, which running 

 anteriorly and medially, unites with the medial division of the 

 ramus palatinus (pal.l + mx.l). The union of the medial max- 

 illaris with the lateral division of the ramus palatinus seems to 

 be but temporary, with little or no mingling of fibers. Before 

 leaving the medial maxillar}^ branch the palatine element gives 

 off a small nerve (fig. 16) which can be traced to the bases of the 

 teeth situated on the maxilla. After leaving the maxillary branch 

 the palatine element runs anteriorly, sending twigs to the choanal 

 epithelium and the bases of the maxillary teeth, and presumably 

 to the lateral oral epithelium (figs. 10, 9, pal.2). The nerve 

 formed by the union of the medial palatine branch and the twig 

 from the medial maxillary division {pal.! + mx.l) seems to inner- 

 vate the medial wall of the choana, the roof of the mouth and 

 the bases of the vomerine teeth (figs. 13-6, 4, 3, 44, pal.l + 

 mx.l). 



The main portion of the medial branch of the ramus maxillaris 

 (mx.l) continues anteriorly along the dorsal border of the pala- 

 tine process of the maxilla and takes a position in a groove in the 

 latter along with the lateral palatine branches to which refer- 

 ence was made above. This groove, farther on opens ventrally, 

 and then becomes a closed canal in the palatine process (figs. 10, 

 12). The canal next becomes a groove opening into the medial 

 ventral part of the tentacular canal (figs. 8, 9, 11), and farther 

 anteriorly becomes a canal again (figs. 4-2), in which the nerve 

 co'ntinues without important branches to the region of the ten- 

 tacular pore, where it is distributed to the sheath of the tentacle and 

 to the skin of the ventral and ventrolateral surfaces of the snout 



