TADPOLES FROM SIAM. 43 



twice as far apart as the nostrils. Spiracnluni sinistral, directed 

 backwards and upwards, a little nearer the eye than the vent. Anal tube 

 short, median, directed backwards and downwards. Mouth subter- 

 minal ; beak broadly edged with black, finely serrated ; papilla; short, 

 at the sides of the mouth only ; upper lip with two long series of teeth, 

 the lower narrowly interrupted ; lower lip with three long series of 

 iininterrupted teeth. Tail short, one and a half times as long as 

 the head and bodj', about three times as long as deep, tip 

 rounded ; crest full, convex, upper equal to or a little deeper than 

 lower, not extending on to the back. Toes webbed at the base. 



Colour. Head and body blackish ; muscular j^ortion of tail pale 

 brown ; membranes almost colourless. 



Dimensions. Total length, 25 mm Head and body, 10 ; depth 

 of tail, 4.5. 



The young on emerging from the water are bronze-brown in 

 colour, usually with a pinkish patch across the snout, and others upon 

 the body, these patches increasing in size and number as the little 

 creature grows. The parietal ridges are not apparent at first, but 

 begin to appear in about five weeks time. 



The tadpoles were found on Khao Sebab, and were taken at the 

 same time and in similar situations as the preceding species. 



In company' with another species of frog with a remarkable 

 dermal flap on the top of its head, and which I believe to be new to 

 Science, liana nigrorittaia and Bufu patvus, were the only Batrachiaus 

 met with upon this hill at any elevation. I was unfortunately just too 

 late tn procure the tadpole of this unknown frog, but found plenty 

 of the J'oung ones just leaving and having left the water. 



Whether these hill dwellers breed at any other time, I do not 

 know, but one is led to infer that it is an instinct of preservation 

 which leads them to spawn at this particular season, the dryest time 

 of the whole year, and the very opposite to that chosen by those 

 species which inhabit the plains. For at no other time could such 

 suitable conditions be found. Every stream on this steep hill during 

 the wet monsoon, must become a small torrent, washing down all 

 before it, and obliterating those quiet pools and backwaters which are 

 so necessary for the development of these tadpoles. 



VOL. 11, JUNE 1!UG. 



