CoGHiLL, Cranial Nen'cs of Aniblysioina. 261 



distinct from the r. buccalis VII, while the r. maxillaris of fishes 

 is fused with the r. buccalis VII for a long distance. More- 

 over, the so-called r. maxillaris of Amblystoma corresponds in 

 a striking manner with the r. maxillaris of fishes in this impor- 

 tant feature. Furthermore, the rr. mandibularis, maxillaris and 

 buccalis of Amblystoma are sometimes fused for a considerable 

 distance into a typical piscine t. infra-orbitalis. 



The relation of the r. maxillaris to the r. palatinus VII, 

 also, should be noticed especially. I have pointed out that the 

 r. maxillaris of Amblystoma differs from that of Rana in this 

 relation. Whether the r. maxillaris of fishes corresponds with 

 that of Amblystoma in this particular cannot be stated cer- 

 tainly, excepting for a few forms. In Gadus and Menidia, two 

 fishes which have been most thoroughly studied form the point 

 of view of nerve components, there is not any contact between 

 the r. maxillaris V and r. palatinus VII (Herkick). Allis has 

 described an anastomosis between these nerves, however, in 

 Amia. Such an anastomosis has been described also in Silurus 

 (see Herrick, 1901, p. 199). However, according to our 

 knowledge of these two anastomoses, they may take place 

 through communis fibers of the r. maxillaris. If they are of 

 such a nature, they have no bearing upon the present discus- 

 sion, since the anastomoses in Amphibia take place through 

 the general cutaneous component of the trigeminus. There is 

 no satisfactory evidence, therefore, that the r. maxillaris of 

 fishes ever agrees with that of Anura in its relation to the r. 

 palatinus VII. 



In the light of these facts concerning the r. maxillaris and 

 "accessory" rami in fishes, Urodela and Anura, I am inclined 

 to think that the so-called maxillaris of Amblystoma and the 

 "accessory" ramus of the tadpole are the morphological repre- 

 sentatives of the r. maxillaris of fishes functionally very much 

 reduced, and that the r. maxillaris of the tadpole is an essen- 

 tially different nerve. This conclusion, however, is only tenta- 

 tive, pending a thorough study of other Amphibia, such as 

 Amphiuma, Siren and Gymnophiona from this point of view. 



M-y third conclusion, concerning the terminal rami of the 



