1918.] G. A. BouLENGER & N. Annan DALE : Rana tigrina. 55 



This form is hardly to be distinguished from the African R. occi- 

 pitalis, Gthr., the range of which extends from the Egyptian Soudan 

 and Uganda to the Senegal and other parts of West Africa as far south as 

 Angola. 1 am not sure I could always tell a Burmese frog from an 

 African, and the tadpoles are identical. Although I have examined 

 over forty specimens of R. occipitalis, I have never seen one with a light 

 vertebral streak. It reaches a length of 130 millimetre from snout to 

 vent. 



Rana cancrivora, Gravenh. 



I have a large material from the Indo-Malay Archipelago which 

 shows that although the toes vary considerably in length, the w^eb 

 between them is always strongly emarginate ; in some specimens even 

 the two last phalanges of the fourth toe are free from the web, and such 

 may be described as having the toes three-fourths webbed. The length 

 of the tibia is If to 2J times in the length of head and body, the heels 

 strongly overlap, and the tibio-tarsal articulation reaches the eye or 

 between the eye and the nostril ; the longer hind limb thus distinguishes 

 the var, cancrivora from the var. hurkilli. The inner metatarsal tubercle 

 is blunt and its length is contained 2| to 3 times in that of the inner toe, 

 8^ to 12 times in that of the tibia. 



The shape of the head varies greatly ; it is often quite as long as 

 broad, and it may even be slightly longer (Padas, N. Borneo) ; the snout 

 may be broadly rounded or as pointed as in any specimen of R. tigrina 

 typica ; when the snout is pointed, the nostril is as a rule equidistant 

 from the eye and the tip of the snout. 



The distance between the eye and the tympanum measures | to | 

 the diameter of the latter (|- to f in the typical form). 



The vomerine teeth vary considerably and often differ from those 

 of the typical form in being disposed in rather short oblique series, well 

 separated from the anterior borders of the choanae ; but some speci- 

 mens (Borneo, .Java, Celebes) have longer and stronger series, which 

 agree entirely with the usual description. 



The longitudinal dermal folds, in the strict sense, are often absent 

 on the body ; if present, they are reduced to 2 or 3 pairs. 



The coloration is much as in the var. hurkilli, but there may be, 

 rather exceptionally, a light streak along the side of the body, as in the 

 typical form (specimens from the Phillippines and Celebes) ; a light 

 vertebral line or broad band is sometimes also present, but it is very 

 rarely accompanied by a light line along the calf (specimens from the 

 Philippines). This is a small form, not exceeding the length of 90 milli- 

 metres from snout to vent assigned to it by Dr. Annandale. 



I will now give a definition of Rana tigrina and of the forms into which 

 it may be divided. 



Rana tigrina, Daud. 



Vomerine teeth in strong or very strong oblique, straight or slightly 

 curved series narrowly separated from each other, originating close to 

 or at a short distance from the anterior border of the choanae and usually 

 extending beyond the level of their posterior borders. Head as long as 



