2. RANA. : 9 
and I therefore do not hesitate to unite Hoplobatrachus ceylanicus 
with Rana tigrina. 
The common Rana esculenta furnishes a similar example in favour 
of this view. In this species the inner metatarsal tubercle is liable 
to considerable variation. Some specimens, especially those from 
S. Europe, N. Africa, and W. Asia, exhibit it blunt, small, one third 
the length of the first toe ; most of those from Northern and Central 
Europe have it compressed, about half as long as the first toe; 
most of the Chinese and Japanese specimens have it still stronger, 
very frequently quite as long as the first toe, and closely resembling 
the spur of Pelobates. I may add that I am inclined to consider 
Hoplobatrachus reinhurdti, Peters, as based upon one of these oriental 
specimens of R. esculenta ; and that I saw some time ago in the 
Paris Museum a large specimen of the same species labelled Hoplo- 
batrachus davidi, sp. n. 
On the other hand, in some species of Pywicephalus, viz. P. nata- 
lensis and P. rugosus, the metatarsal tubercle is not more developed 
than in that form of R. esculenta which is intermediate between 
the extremes. 
As regards the stouter habit and the thicker head of Pywicephalus 
as compared with Rana, we must bear in mind that the latter genus 
includes some very stout species, and that P. natalensis has the head 
very much like the majority of the species of Rana. 
Synopsis of the Species, 
I, Patmarctric Srrcres. 
A. Tips of fingers and toes not dilated ; belly smooth. 
1. Vomerine teeth between the choane; a glandular lateral 
fold; toes entirely webbed. 
Fingers pointed ; glandular lateral fold as 
broad as the upper eyelid; a dark band 
along the hinder side of the thighs 
Fingers blunt; glandular lateral fold nar- 
rower than the upper eyelid ; hinder side 
ie Gheiehie TAB DECO. GNhe, a5 v. Sade: jo oy Se 39. esculenta, p. 38. - 
Upper eyelid glandular and distinctly porous 40. porosa, p. 40. 
(Sy 
CO 
. plancyi, p. 37. 
2. Vomerine teeth between the choane ; no glandular lateral 
fold ; toes incompletely webbed. 
Skin very WHOUVOES ava sO ia ss Soins aad 33. rugosa, p. 35. 
3. Vomerine teeth extending beyond the level of the hinder 
edge of the choanz ; a glandular lateral fold; toes in- 
completely webbed; a dark temporal spot. 
a, Tibio-tarsal articulation not or hardly reaching the tip 
of the snout. 
Inner metatarsal tubercle blunt; snout 
CATE A ae 3.595. ba a's oe ew 2 50. temporaria, p. 44. 
