48 INTRODUCTION. 



diapophysis usually about once and a half as 

 long as tlie seventh. 



1. Fronto-parietals convex, narrow; nasals 



with straight or slightly concave posterior 

 border. 

 Nasals widely separated from each other ; tibia 

 nearly twice as long as the tarsus. 



B. arvalis. 



Nasals narrowly separated ; tibia more than 



twice as long as the tarsus . B. camerani. 



2. Fronto-parietals flat, broad. 



Nasals with concave posterior border; tibia 

 slightly longer than femur . B. temporaria. 



Nasals with straight or convex posterior 

 border; tibia considerably longer than femur; 

 distal phalanges with very distinct trans- 

 verse expansion at the end* . . B. grascci. 



Nasals with concave posterior border; tibia 

 considerably longer than femur . B. iberica. 



Nasals with straight or feebly concave posterior 

 border; tibia considerably longer than femur. 



B. latastii. 



3. Fronto-parietals grooved, moderately broad ; 



nasals with straight or slightly concave 

 posterior border ; tibia considerably longer 

 than femur B. agilis. 



The above key, it must be observed, is drawn up 

 from skeletons of adult, or at least half-grown speci- 

 mens, and must necessarily often fail in its object if 

 applied to young ones. 



* Quite as much developed as in the species on which the genus 

 Hylorana oi- Livmodytes has been founded. I have pointed out that 

 certain Chinese and Burmese forms show a passage to exist from the 

 Baiife temporarise to the Hyloranm, and this view is further confirmed 

 by a study of Rana greeca. 



