HERPETOLOGY OF JAPAN. 15 



Genus DIEMICTYLUS " Rafinesque. 



1820. Diemidj/lus Rafinesque, Annals of Nature. 1820, No. 1, p. 5 (type, T. 



viridescens). 

 1820. Notophfhalmus Rafinesque, Annals of Nature, 1820, No. 1, p. 5 (type, 



T. miniatus). 

 1838, Cynops Tschudi, Classif. Batr., p. 94 (type. C. suhcristatus). 

 1850. Taricha Gray, Cat. Batr. Grad. Brit. Mus., p. 25 (type, T. torosa). 

 1858. Diemydylus Hallowell, Journ. Phila. Acad. (2), III, p. 362 (emendation). 



1878. Triturus Boulenger, Bull. Soc. Zool. France, III, p. 307 (type, T. viri- 



descens) (not of Rafinesque, 1815). 



1879. Pelonectes Lataste, Rev. Internat. Sci., Ill (p. 275), (type, P. boscai) (not 

 of Fitzinger, 1843). 



Professor Cope (Bull. U. S. Nat. Mus., No. 34, p. 203) has raised 

 the question whether Rafinesque' s Diemictylus has the priority over 

 Merrem's Molge or not, both having been proposed in 1820. The 

 question is immaterial, however, since Molge is a strict synonym of 

 Triturus, Rafines([ue (1815), both the latter names being assuredly 

 only substitute names for Triton, preoccupied; hence they are in 

 every respect identical and can not be used independently for dif- 

 ferent sections of the original genus Triton. Molge can never be 

 used unless Triturus should become unavailable for some reason not 

 now apparent. To the latter belong the species without a bon}^ 

 fronto-squamosal arch. 



Two species of Diemictylus occur in Japan, one peculiar to Kiusiu, 

 Hondo, and Shikoku, the other confined to the northern and central 

 Riu Kius. The latter is a broader-lieaded form with shorter digits 

 and longer tail, and Boulenger also indicates certain differences in 

 the coloration of the live animals. The structural differences are 

 very difficult to express in definite terms on account of the sexual 

 and individual variability of these forms. It appears that the males 

 have relatively longer digits than the females; consequently, in the 

 female D. pyrrhogaster the digits are of about the same relative 

 length as in the male D. ensicauda. On the other hand, the length 

 of the tail — though undoubtedly averaging considerably longer in 

 D. ensicauda — varies to such an extent individually as to baffle all 

 my attempts at using it diagnostically. The head of the latter is 

 also decidedly larger, but the variability of the other proportions ren- 

 ders the use of it illusory as a unit for comparative measurements. 

 Nevertheless, the two forms are quite distinct, and it may be that a 

 larger series of D. ensicauda in good condition (many of my specimens 

 being rather hard and dry) will yield better results in the future. 



« Derivation and meaning obscure. Two derivations suggest themselves, namely, 

 dia/ivKTOi, from dia/.nyvv/it, or Si-'^uiKorvAog, hwt the ajaplication of neither is 

 obvious. 



