PREFACE. XIX 



The territory embraced in the present work (see Plate I) consists 

 of what is known as Japan proper — i. e., the four main islands and 

 their immediately adjacent islets, the Riu Kiu Archipelago, Formosa, 

 the Bonin Islands, Korea, Sakhalin, Amiirland, and the Russian Coast 

 Province, as well as the Chinese provinces of Manchuria and Pechili. 

 A few species, mostly marine snakes, not hitherto recorded from 

 within this territory have been included because of the probability 

 of their occurrence; but these have been inclosed in brackets. 



Analytical keys for the easy and sure identification of the groups 

 and species are provided. It must be understood, however, that 

 reptiles and batrachians are often subject to individual variation far 

 in excess of the true specific (or subspecific) and even generic limits. 

 In all cases, therefore, the specimens should be compared with the 

 detailed descriptions. These are not generalized diagnoses, however, 

 but minute descriptions of individuals, the deviations of other speci- 

 mens under observation being noted under the heading "Variation." 

 In selecting specimens for description or for illustration I have chosen 

 individuals collected inside the territorial limits of this work whenever 

 possible. Preferably the type-specimen has been described, or, if not 

 available, a specimen from the type-locality or from the nearest 

 locality to that of the type. If more than one specimen of this 

 character were avaliable, the one showing the species in its typical 

 and normal development has been selected. 



Full synonymy of each genus and species has been given, with 

 references to nearly all the published records of the species within 

 the territorial limits. At the end a bibliography is provided, giving 

 full titles of publications specifically referring to the herpetological 

 fauna of the territory. 



Special attention has been given to the geographical distribution 

 of the various forms. Unfortunately, a large number of specimens 

 in the old collections are credited to ''Japan,'' or "Loochoo," or 

 "Formosa," without further particulars, and a good many others 

 have wrong localities attached to them. Much critical work has been 

 done to clear the records in the latter cases. Nevertheless, the range 

 of very many species is as yet only very imperfectly known. Large 

 portions of the territory included are still unexplored, and many islands 

 are as yet unvisited by a scientific collector. With regard to the 

 vertical distribution, it is known only imperfectly in the great majority 

 of cases. To help resident and visiting naturalists remedy these 

 defects in our knowledge this work has been largely undertaken. It 

 was at first intended to accompany this account by a general tabula- 

 tion of the geographical distribution of the various forms and a full 

 discussion of their origin and dispersal, but tliis will be treated of 

 by the author in a separate paper. 



