THE SYSTEMATIC VALUE OF RANA CHINENSIS OSBECK 8 1 



and position of the vomerine teeth group. The bony ridge visible 

 on the diapophysis of the third vertebra of the vertebral column, as 

 well as the characteristics in connection with the pelvis, are also 

 exceedingly important marks. 



I cannot, after these results, accept Wolterstorff's opinion (17, 

 p. 139) that the Chinese frog is a now-arising, not yet fully expressed 

 species, whose characteristics in the formation of the legs have not 

 yet quite developed in each specimen. With regard to the meta- 

 tarsal tubercle, my conviction is that it has reached its full develop- 

 ment, but that, owing to climatic conditions and natural surround- 

 ings it varies in formation according to countries. 



If we look back upon what has been said above, it becomes imme- 

 diately clear to us that the Chinese frog bears the mixed charac- 

 teristics of R. ridibunda and R. esculenta, and it is just this mixture 

 of distinctive features which proves that we have to do with inde- 

 pendent species. This is also confirmed by its geographic dis- 

 tribution. The Chinese frog is to be found as is reported from 

 Vladivostok in the North down to Bangkok in the South, and from 

 Japan westwards to the 105-110 eastern longitude. In opposition 

 to this Rana esculenta, respectively the var. lessonce, is to be found 

 until the 30 eastern longitude, whilst ridibunda is met with as far 

 as Persia. The fact of its geographic distribution being confined 

 within such definite limits, seems to be a proof more, that R. chin- 

 ensis belongs to an independent species as it were difficult to sup- 

 pose that alone one variety of esculenta lived on such an immense 

 territory, within so great a distance of the circle limiting the typical 

 form's natural boundaries. If R. chinensis meets with any western 

 species it can only be with Rana ridibunda. Boulenger supplies 

 us in his work "The Tailless Batrachians of Europe," with a map 

 (p. 263) marking the esculenta group's geographic distribution. 

 Wolterstorff remarks (17, p. 142) that on this map he finds the 

 limits of Rana chinensis' geographic distribution rather far extended 

 westwards. My opinion is that the distance between these two 

 species is not even as great as that, but that they most likely directly 

 meet somewhere. This question could only be solved by a minute 

 investigation in the regions of Asia Minor and Tien-san. 



My studies on the Chinese frog have led me to the conclusion that 

 it is not the Chinese frog which originates from R. esculenta or R. 



