232 PROCEEDINGS OF THE ACADEMY OF [1893. 



The manner, however, in which the blood passes to and from the 

 lungs is the same in both animals. The genito-urinary apparatus of 

 the Japanese Menopoma does not differ from that of the American 

 animal. As in the case of the skull, the latter is but a miniature 

 of the former. 



From the above resume of the organization of the two batrach- 

 ians, it will be observed that the Japanese differs from the American 

 animal in one essential respect, and only one, viz. : in the absence of 

 the spiraculum or gill opening, and the modification of the hyoid 

 apparatus conditioned thereby. That little or no importance can be 

 attached to the presence or absence of the spiraculum as serving as a 

 generic character or as warranting the establishing of the distinct 

 genus Meg alobatrac hits, is shown by the fact of the spiraculum not 

 being always present in Menopoma. At least, in one instance, its 

 absence was observed by Boulenger. 18 



If the views here advanced as to the nature of the Japanese 

 batrachian be accepted, if it be admitted that it is a large Menopoma 

 — a Cryptobranchus — it will illustrate once more the truth of the 

 Linnsean maxim : " una nota non facit genus," the true affinities of 

 an animal being determined, not by the presence or absence of a par- 

 ticular structure, but by the character of its entire organization. 

 The position occupied by the Japanese Cryptobranchus or Menopoma 

 among the Urodela, if the animal be admitted to be such, would 

 then be between the Derotremata and Myctodera, according to the 

 old classification of Stannius, 19 bridging over the gap between these 

 groups to such an extent that their taxonomic value loses most of 

 its significance. 



f Siredon 

 I Siren 

 Perennibranchiata j Proteus 



[ Menobranchus 



rT . . , f Amphiuma 



L ' erouemata \ Cryptobranchus alleghaniensis 



. Abranchiata \ Cryptobranchus maximus 



Urodela ■ 



Myctodera {™° m n andra 



In conclusion it may not be uninteresting to call attention to the 

 fact that the Japanese Cryptobranchus was not always restricted to 

 Japan and China as it appears to be at present, it having, at one 



18 Op. cit. p. 82. 



19 Stannius, Op. cit. S. 4. 



