900 MR. S. S. FLOWER ON THE REPTILES AND [ Dec. 1, 
before, I can find no constant characters to separate the two 
varieties, the following points should be noticed :— 
(i.) Breadth of interorbital space compared to the distance 
between the nostrils. 
(ii.) General form of the snout. 
(iii.) Shape and prominence of the tympanic fold. 
(iv.) Shape of the tympanum. 
(v.) Amount of emargination in the webbing of the hind 
toes. 
Localities. Of the Penang variety 1 collected seven specimens 
in small ponds on Penang Hill, at elevations of from 2000’ to 2200, 
in March 1896. They are active frogs and good swimmers, and 
locally called ‘*‘ Koldok-ayer” (Malay). There is in the British 
Museum a specimen from Mr. Wray, from the hills of Larut, 
Perak, at an elevation of between 3000’ and 4000’, which agrees 
with the Penang variety in the more pointed snout, in the distance 
between the nostrils being greater than the interorbital space, in 
the skin having longitudinal glaudular folds, and in the webbing 
of the hind feet, but the tympanic fold is angular. 
Of the Singapore variety I collected eight specimens from the 
following places in the island—Passir Panjang, Botanical Gardens, 
and Bukit Timah, at elevations of less than 400 ft., m January and 
April 1896. Four large specimens from Dr. Dennys, one from the 
Raffles Museum, and three young specimens from Mr. Ridley, all 
from Singapore, and now in the British Museum, agree with my 
specimens of corresponding sizes, and are distinctly of this variety, 
the full-grown ones showing well the characteristic broad head 
and angular prominent tympanic fold. There are several large 
specimens of this variety in the Raffles Museum, Singapore; one 
(in spirit) has a Dryophis prasinus in its mouth. This Frog seems 
common but local in Singapore island, and is known as the “ red 
frog” or “ Koldok-merah” (Malay): it is a very handsome animal 
from its athletic build, bright eye, and brilliant colour, which last, 
however, helps to conceal the frog when (as I have more than once 
found it) among large fallen leaves of the same bright red as itself. 
When frightened, both the Penang and Singapore varieties take to 
the water, diving straight in and seeking concealment immediately 
at the bottom. 
Although, as far as we know, only the one variety inhabits 
Penang and the other Singapore, there are specimens of both in 
the British Museum from Java, and also from Borneo, where are 
also intermediate forms with the angular tympanic fold, but the 
distance between the nostrils greater than the interorbital space, 
and with fully-webbed hind feet. There is a specimen in the 
British Museum from Great Natuna Island, from Mr. Hose, which 
seems identical with the Singapore variety. 
Colour, from life. Specimens from Penang Hill.—Upper parts 
rich dark olive-brown or green, with or without a broad orange 
vertebral line. Chin white. Belly and lower side of limbs pale 
orange. 
