ZOOI.OOY OF THK FAR HAST. 
fold, almost in the position in which the tubercle would be present, a distinct white 
spot can often be detected. In my opinion this spot must be regarded as a vestigial 
tubercle and indicates immediate descent from a form possessing the tubercle. I can 
find no spot in this position in specimens of R. tigrina or R. rugulosa. 
The second fact is, that specimens of R. tigrina are occasionally found in India 
which approximate to R. rugulosa both in form and in colouration. There are two 
individuals in the collection of the Indian Museum that exhibit this tendency to a 
marked degree. One is from Orissa and the other from south-western India. More- 
over, in frogs from Upper Burma there is, to some extent a gradation, between the 
two species. 
For these reasons I am inclined to believe that R. tigrina and R. rugulosa are, 
strictly speaking, no more than two local races of a single species, u.sing the term 
species in its broadest sense; whereas R. cancrivora is closely connected with R. 
limnocharis and r&sembles R. tigrina owing to convergence. 
R. wasl is possibly in the strict sense of the phrase a connecting link between the 
R. limnocharis and R. cancrivora. 
FROGS OF THE RANA LIEBIGII GROUP. 
Key to Rana lichii>ii and alued species from the Himal.was. 
1. Skin of back devoid of minute spinose warts and of elongate non-spinose 
warts. 
A. Skin of back smooth or witli relatively large, ill-defined prominences : 
a dark line, pale-edged, usually present along each side of the back : 
throat suffused with dark pigment : chest and abdomen pale, immacu- 
late. Arms and chest unmodified, skin surrovinding vent spinose in 
breeding male . . . . . . . . . . R. vidua. 
B. Skin of back more or less warty: no dark dorso-lateral lines: whole of 
the ventral surface suffused with dark pigment ; arms and chest spini- 
ferous, no spinose skin round vent, in breeding male . . . . R. liehigii. 
2. .Skin of back bearing minute scattered warts of a more or less spinose char- 
acter. (Arms and chest spiniferous in breeding male). 
A. Habit rather shght: total length not exceeding ()0 mm.: dorsal surface 
mottled: throat and chest minutely spotted, abdomen pale, immacu- 
late . . . . . . . . . • . . R. gammiei. 
n. Habit stout, total length reaching 85 mm.: dorsal surface uniformly 
dark : whole of ventral surface covered with an interrupted reticula- 
tion of dark spots and lines on a pale background . . R. s'ernosignata. 
3. Back bearing short oval or linear, non-spinose warts : length not exceeding 
40 mm. (No structural modifications in breeding male) . . . . R. blanjordit. 
Rana liebigii (Gunther). 
i86n. Rana liebigii. Ciunther, Proc. Zool. Soc. London, p. 157, pi. xxviii. lig. A. 
1882. Rana lichigii, Boulenger. Cat. Bair. Sal. B.M., p. 22, fig. (text in part only). 
This is the largest and heaviest form of the alliance. To the naked eye it appears 
more warty than any of the others. There is, however, no trace of spinose cornified 
