McGregor, Cranial Nerves of Cryptobranc/ms. 49 



marked lateral line sense-organs, we find the rami of the dorsal 

 VII root, or Vllb. of Strong, well developed. The fibres of 

 the Rr. ophthahnicus siiperficialis and buccalis are very probably, 

 judging from analogy with the frog larva, contained in a large 

 root (VII u and / of Osborn) which enters the caudal border of 

 the Gasserian ganglion. These two rami leave the ganglion in 

 company with ranms maxillaris superioris passing with it dorsad 

 of m. temporalis. Ramus ophthahnicus superficiahs VII runs 

 cephalad to the nostril, innervating the supra-orbital sense-organs 

 of the lateral line system. This ramus seems to have been en- 

 tirely overlooked by Fischer, and several recent writers have 

 called it ra^mis frontalis V. Its community of origin with other 

 lateral line rami, as shown by Strong, and its distribution to 

 the region of the supra-orbital line of sense-organs leaves no 

 doubt as to its true nature. Ramus buccalis VII accompanies 

 ratnns maxillaris superioris V as far as the eye and ends in the 

 infra-orbital sense-organs. This is not the homologue of the 

 ramus buccalis as described by von Plessen and Rabinovicz and 

 by C. J. Herrick, but the ramus maxillaris V o( these writers 

 no doubt includes the ramus buccalis as the name is here used. 

 The root marked d in the figures of Salamandra given by von 

 Plessen and Rabinovicz and of Amblystoma by Herrick is prob- 

 ably homologous with the VII // and / of Crytobranchus as fig- 

 ured by Osborn and probably contains the fibres of the two 

 lateral line rami here described. 



Besides the two rami of the VII already described there 

 are four others, all of which were described by Fischer, who 

 called them Rr. palatinus, mentalis, alveolaris and jugiilaris. 

 Ramus palatinus is rather small ; it passes ventrad through a 

 foramen in the prootic ossification and is covered ventrally for 

 some distance by the very broad parasphenoid bone. Near the 

 level of the posterior nares it forms anastomoses with Rr. oph- 

 thalmicus profundus V and maxillaris superioris V. On account 

 of its anastomoses the ultimate distribution of the facialis fibres 

 can be determined only by serial sections through the head. 

 The ramus alveolaris of Fischer runs laterad along the dorsal 

 surface of the squamosal bone, then cephalad between m. masse- 



