80 BOLKAY 



that in some parts R. chinensis lives an exactly similar life to that 

 of our R. esculenta (Killing, Masempho). 



In Wolterstorff's already mentioned article (17, p. 140) we read 

 that the meta-tarsal tubercle of ridibunda, esculenta, and var. 

 lessonce stands in contrary proportion to the length of the tibia, 

 that is to say, that the larger the meta-tarsal tubercle, the 

 shorter the tibia and reciprocally. He explains this occurrence by 

 the law of correlation; according to his opinion the R. ridibunda' s 

 leaping faculties are increased through the tibias' length, whilst 

 those of esculenta and var. lessonce are augmented by the larger size 

 of the meta-tarsal tubercle. He then continues saying: "If the 

 R. chinensis also belonged directly to this series of development, 

 then — considering the size of the meta-tarsal tubercle — the tibia 

 ought to be shorter still, yet just the contrary is stated as it is longer." 

 Wolterstorff further remarks that when hind limbs are bent at right 

 angles to axis of body the heels meet or even rather extend beyond 

 each other. This is stated by Boulenger also (6). 



On the specimens examined I found that the heels never meet. 

 The reason of this can easily be explained by the Chinese frog's 

 peculiar mode of life. As its burrowing faculties gave it the pos- 

 sibility of remaining in its accustomed place in spite of the water 

 drying up, there was no necessity for wandering, thus its leaping 

 faculties did not particularly develop whilst it possesses the bur- 

 rowing-faculty's requisites, viz.: thickly set, strong hind limbs. 

 I shall refer later on to the great modification, which wandering 

 may cause in the length of the hind limbs. 



After this I am not astonished, that Bedriaga's (17, p. 140) 

 Ordos' specimen was found similar in the length of the hind limbs 

 to var. lessonce of Norfolk. 



Referring to the explanation given on the skeleton's distinctive 

 features, I must here again insist upon the fact that they are — 

 according to my opinion — the most important, as the skeletons 

 which I prepared all present the above mentioned characteristic 

 marks, although they belonged to frogs originating from different 

 places. The particularities most worthy of attention are on the 

 skull: the position of nasals, the shape and dimensions of the zygo- 

 matic process as well as the fact of the condylus always extending 

 beyond the line joining the articulation of the jaws, finally the shape 



