No. 2.] A MP HI UM A MEANS. 407 



fructification and incubation of the eggs, the habits of the young, 

 the degenerate hmbs, the unusual disposition of the transver- 

 salis-abdominis, the inequality of the length of the lungs, the 

 anterior hypapophyses and the amphicoelous vertebrae, all of 

 which these two families possess in common, point to a common 

 parent form of the Coeciliidae and Amphimnidae. The numer- 

 ous differences in the skull structure of the two families make 

 it manifest that the common ancestor is a form far back in Ge- 

 ologic time ; a fact which tends to verify Wiedersheim's state- 

 ment that the origin of the Coeciliidae is to be sought in the 

 Stegocephalans of the Carboniferous. The well-developed 

 columella auris of AmpJmivia is very probably a character re- 

 tained from the GanocepJiala and RacJiitomi. In the light of 

 present paleontological and embryological knowledge any de- 

 tailed phylogeny of Amphibia must be very uncertain. How- 

 ever, the facts at hand seem to me of such significance as to 

 warrant the following table : — 



Salientia Amphiumidae 



Gymnophiona Urodela Trachystomata 



\ / 



Proteida 



/ 



Embolomeri Stegocephali 



/ 



Rachitomi 



Ganocephala 



Although AmpJiimna is considered a degenerate form, yet 

 certain parts of its structure are highly specialized. The 

 general shape of the cranium presents a marked contrast in 

 comparison with other Amphibian skulls. The great length of 

 the face and the pointed snout are of no phylogenetic signifi- 

 cance, as they have been developed by the habits of the animal. 

 The vertebrae with their numerous processes cannot be ac- 

 counted for on any other ground than that of adaptation to the 

 mode of life which rendered it necessary that a complex trunk 



