228 DR. MALCOLM SMITH ON 



This frog appears to be confined to the Malay Peninsula. The 

 type specimen came from Penang or Province Wellesley and is now 

 lost. Flower's specimen came from Penang, and there is one in the 

 British Museum from Singapore. I have another from Gomhak, 

 Selangor, a female with ripe ova (No. 1592). 



Tadpoles (taken in June), and juveniles just leaving the 

 water, which I identify as those of liana 'plicaiella were also 

 obtained. The larva differs from that of R. m. macrognaihus and 

 R. kohchangce in the longer and narrower tail, and in that the upper 

 crest does not reach to the root of the tail. I take this opportunity 

 to add some details of description which were omitted previously. 



Length of head and body one and a half to one and two- 

 thirds times its breadth. Nostrils a little wider apart than the 

 distance between the eyes, equidistant between them and the tip of 

 the snout. Spiraculum visible both from above and below. Mouth 

 with a single short row of papillae on the sides, with one or two 

 rows of more elongate ones below, not interrupted in the mid-lino. 



Tail five times as long as deep, the crests somewhat narrow, 

 the upper a little higher than the lower and not reaching to the root 

 of the tail. 



Measurements of a specimen with hind legs well developed : — 



Total length 34 mm; head and body 11.5 ; depth of tail 4.5. 



The study of this small group of frogs, from an evolutionary 

 point of view is of great interest, for in this case there can hardly 

 be any doubt that they are all derived from the same ancestor. The 

 one doubt refers to R. dorice, which, being the least specialized I 

 have assumed to be the progenitor, but which now, in its lack of 

 cranial enlargement and want of tooth-like projection in the lower 

 jaw, is farther separated from the various members of the group than 

 they are from each other. 



Considering the comparatively small area of country over 

 which these frogs are spread, the number of forms which have been 

 evolved is indeed remarkable, and all tho more so when we consider 

 that the conditions under which they all live are almost identical. 



JOURX. NAT. HIST. SOC. SI AM. 



