138 IOWA ACADEMY OP SCIENCE 



ausschliesslichen Wasserleben zuruckkehrten. " Druner says fa;'ther: 

 "Die Perennibranchiaten sind eben Larvenformen ebenso wie die Lar- 

 venformen der Salamandriden und Siredon, welche in der Phylogenie 

 des Urodelenstammes niemals realitat besessen haben." 



Recently Ganpp (1911) in reference to the reduction of the prim- 

 ordial cranium in Necturus says: "Als 'primitiv' wird man dieses 

 Verhalten wohl nicht bezeiehnen konnen. " 



Miss Emerson (1905) from her studies on Typhlomolge concludes 

 that the latter, which was placed by Stejneger (1895) among the Pro- 

 teidae with Proteus and Necturus, "should be classed with Spelerpes 

 in the family Salamandridae and the subfamily Plethodontinae. " She 

 believes that there are fundamental differences between Typhlomolge 

 and the Proteidae in just those respects in which the former resembles 

 Spelerpes, and that to place Necturus and Proteus in the same family 

 with Spelerpes is untenable. Wilder in a foot-note to the paper by 

 Miss Emerson expresses the opinion that Necturus and Proteus can- 

 not be placed among the Plethodontidae "since all the members of this 

 family are, so far as is known, lungless, a condition which allows 

 Typhlomolge to be included within this family, but seems to exclude 

 the others." 



Cope (1889) derived the tailed amphibians from the Stegocephali by 

 way of the Proteidae, considering the Cryptobranchidae as next higher 

 in rank. 



The writer, in collaboration with Miss Buckley, in tracing the origin 

 and distribution of the cranial nerves in Necturus was soon convinced 

 that the resemblances to the conditions in Spelerpes bilineatus as de- 

 scribed by Miss Bowers (1900) were far from superficial, and that they 

 signified a much closer relationship than has been suspected hitherto. 

 Basing sweeping changes in classification upon a single system of the 

 body is a dangerous procedure, but the nervous system is very con- 

 servative and whatevei* evidence it offers must be taken into considera- 

 tion. The following comparisons between the cranial nerves of Nec- 

 turus and Spelerpes are based upon personal investigations in both 

 species, the paper of Miss Bowers being found defective in its omis- 

 sions and errors. 



Lee (1893) has shown that in Spelerpes fuscus the olfactory glom- 

 eruli are in two groups, an anterior ventral and a posterior dorsal, 

 not sharply separated from each other. A similar arrangement occurs 

 in S. bilineatus and in Necturus. Horizontal sections through the olfac- 

 tory lobes of the adult Necturus show that the olfactory nerve arises 



