140 IOWA ACADEMY OF SCIENCE 



stomosis in both cases seem to be different from that in Amblystoma, 

 Amphiuma and Siren, and much like that described by Coghill (1906) 

 in Triton. The r. max. in both Necturus and Spelerpes leaves the gas- 

 serian ganglion as a distinct n«rve but almost immediately joins the r. 

 buccalis VII. The two show little if any actual fusion, but run parallel 

 to each other antero-ventrally around the ventro-lateral border of the 

 eyeball, the r. maxillaris on the inner border of the r. bue. At the 

 transverse level of the anterior portion of the eyeball the r. max. is 

 given off in a number of branches, while the r. bue. passes anteriorly 

 to the tip of the snout. This origin and distribution of the infra-orbital 

 trunk is almost identical with that in Amblystoma, and doubtless is 

 characteristic of the Salamandridae. In Necturus a general cutaneous 

 component enters the r. ophthalmicus superficialis VII from the gas- 

 serian ganglion. The writer finds no such component in Spelerpes, al- 

 though it evidently occurs in the closely related genus, Plethodon (Nor- 

 ris, 1909). 



Kingsbury (1895) describes the "dorsal VII" as arising from the 

 brain by two rootlets in Necturus. In larvae of Necturus 35 mm. in 

 length the writer finds three rootlets of this nerve, the dorsal of which 

 is very small and almost amyelinic. Similarly in the larvae of Spelerpes 

 there are three rootlets on the dorsal VII, the most dorsal of which is 

 extremely small and barely discernible. In Amphiuma and Siren a 

 similar condition is found, but the dorsal rootlet is much better de- 

 veloped. The general distribution of the lateral line component of the 

 seventh nerve is almost identical in the two species. The ramus pala- 

 tinus VII is relatively larger in Spelerpes. The ophthalmic-palatine 

 anastomosis has already been mentioned. A definite Jaeobson's com- 

 missure from the r. pharyngeus IX to the r. palatinus occurs in both 

 species only to the extent mentioned by Druner, that is, twigs from the 

 r. pharyngeus anastomose with twigs from the r. palatinus. This is 

 much like the condition in Amblystoma, only more difuse. In both 

 Necturus and Spelerpes the r. alveolaris VII receives a communis com- 

 ponent from the ramus communicans IX-X and VII, in this respect 

 resembling Amblystoma, and differing from Amphiuma and Siren. In 

 Spelerpes the r. alveolaris after reaching the vicinity of the angle of 

 the jaw divides sending a branch into a canal in the jaw (Miss Bowers 

 to the contrary), which branch unites farther anteriorly with a branch 

 of the r. md. V already described. In Necturus the alveolaris does not 

 enter a canal in the jaw, but does come into close relations with a 

 branch of the r. md. V which itself enters a canal in the jaw. In both 

 Necturus and Spelerpes owing to the early separation of the r. jugu- 



