1918.] G. A. BouLENGER & N. AnnajNdale : Rana tigrina. 59 



II. FURTHER NOTES ON RANA TIGRINA AND ALLIED FORMS. 



By N. x4nnandale. 



Rana tigrina is one of the commonest Indian frogs and is used for 

 dissection in all the North Indian colleges in which practical zoology 

 is taught. Its identity is therefore a matter of more than usual interest 

 to naturalists in India. I have recently expressed the opinion ^ that 

 the species should be divided into three forms, which I have treated as 

 specifically distinct. I have, however, pointed out that one of these 

 forms {R. cancrirora, Gravenhorst) stands on a somewhat different 

 footing from the other two (o/;. cit., p. 136). Dr. G. A. Boulenger has 

 replied to my observations in a paper printed immediately before this 

 one. He holds that not three but five forms must be recognized. In this 

 I am in agreement with him, but he differs from me in regarding all 

 these forms as varieties or races of a single species. I am glad that my 

 remarks have at any rate called his vast experience to bear on the 

 problem, but there are still certain points both general and particular 

 in which I find myself unable to accept his decision. 



In the first place he expresses the opinion that if I had had a larger 

 collection before me I would probably have come to conclusions other 

 than those I arrived at with only the specimens in the Indian Museum 

 to examine. This may be true, but only with qualifications. If I had 

 had both this and the British Museum collections before me at the 

 same time I would certainly have recognized the Madras form as dis- 

 tinct, but I do not think from what he says that I would have had reason 

 to alter my views as to either the geographical or, \Aith the exception 

 stated, the taxonomic limits of the three forms that I recognized. The 

 correct names (specific or racial) of the forms discussed (as distinct from 

 their identity) depend, in the absence of adequate original descriptions, 

 not on the examination of a large number of specimens from different 

 localities, but rather on geographical considerations and on the inter- 

 pretation of published figures. 



The question whether the forms under discussion should be called 

 species or races depends on one's concept of these terms — a subject on 

 which a difference of opinion is perhaps legitimate. I have called cer- 

 tain forms allied to R. limnocharis " races or sub-species,'' though Dr. 

 Boulenger recognizes them as distinct species. My reason for this has 

 been that the forms which I regard as mere races are to some extent 

 isolated geographically and that a considerable proportion of the in- 

 dividuals representing each differ from the forma iypica in relatively 

 unimportant characters such as size and colour. On the other hand 

 I call forms included under the specific name Rana tigrina by Dr. 

 Boulenger " species," because they are not isolated geographically but 

 occur over large areas together, and because I do not think that indivi- 

 duals intermediate in character ordinarily occur. 



The following notes on the four forms that occur in the Indian Empire 

 and the Malay Peninsula are based mainly on the examination of living 



1 Mtm. As. Soc. Bengal, Vol. VI, part II, 1917. 



