CRANIAL NERVES OF CAECILIANS 529 



The jugularis in the larva of Ichthyophis also innervates a 

 levator hyoidei and a ceratohyoideus externus muscle (fig. 41, 

 Ih., che.). 



In Dermophis the muscles innervated by the ramus jugularis 

 have much the same relative proportions as in Herpele. In 

 Geotrypetes there is a sharp distinction between the interhyoideus 

 and omo-humero-maxillaris muscles. 



4. The ramus ophthalmicus superficialis VII 



As stated above (pp. 524, 525) there is in the root of the facialis 

 nerve a tract of fibers which enters a dorsal region of the medulla 

 and seems to represent a lateral-line center (fig. 28). This tract 

 becomes ganglionated in a small mass of cells on the posterior dor- 

 sal border of the Gasserian ganglion, but seems to receive fibers 

 from the geniculate ganglion. Its course through the Gasserian 

 ganglion is easy to follow. As described in a previous section 

 (p. 520), it anastomoses peripherally with branches of the ramus 

 ophthalmicus profundus, and is evidently distributed to the 

 skin. Although no neuromasts were found, the nerve, from its 

 connections and relationships, is beyond question a representa- 

 tive of the ramus ophthalmicus superficialis. The fibers which 

 it receives from the geniculate ganglion are supposedly visceral 

 sensory, but their special distribution is unknown. In Dermo- 

 phis the geniculate and Gasserian ganglia are not in contact, but 

 this ramus bridges over the gap between them. In Geotrypetes 

 it is wanting. 



Waldschmidt describes and figures in Epicrium (Ichthyophis) 

 a small cutaneous nerve which he believes to arise from the Gas- 

 serian ganglion, and which is undoubtedly this ramus ophthal- 

 micus superficialis. Waldschmidt's commissure between the 

 geniculate and Gasserian ganglia is probably this same nerve 

 passing from the facialis root into the Gasserian ganglion. Mar- 

 cus describes a ramus ophthalmicus superficialis in the trigemi- 

 nus of Hypogeophis. 



