526 ME. G. A. BOULENGEE ON NEW [Juue 6, 



I am glad to be able to supplement tbis description of tbe adult 

 witb an account of tbe very remarkable larval characters furnished 

 by a specimen, undoubtedly of the same species, at the close of the 

 larval period, obtained by Mr. Everett at Bongon, N. Borneo. 



The breast is covered witb a large sucking-disk, free on its 

 borders, truncate in front. The lips are much developed, not 

 fringed, and armed with numerous series of horny teeth forming 

 3 uninterrupted and 8 paired rows on the upper lip, and 4 uninter- 

 rupted and 1 interrupted ros^s in the lower lip, disposed as show'n 

 in the figure. The horny beak is formed of au upper and a lower 

 mandible, both of which are angular, smooth, and very finely 

 denticulate at the edge. The larva is so far advanced that I am 

 unable to say anything of the other larval characters. But in the 

 important points of the structure of the mouth and ventral disk 

 it shows the greatest resemblance to some hitherto undetermined 

 larvae from Bantam, Java, which I described and figured in 1882 

 (Cat. Batr. Ecaud. p. 89). At that time the only Frog known to 

 inhabit Java that possessed fully webbed toes dilated into large 

 disks, as shown by one of the larvae, was Rhacophorus reimvardti • 

 and I therefore referred them " provisionally, not without doubt," 

 to that species. That this reserve was warranted, is shown by 

 the discovery in Java soon after of a Erog, Rana masonii, Blgr. 

 {z=jerboa, Gthr.), agreeing in the above points with the larvae in 

 question, which I have now no doubt belong to it. Numerous larvae 

 of an allied species, R. whiteheadi, Blgr., at all stages of deve- 

 lopment, hence easily determinable, were collected by Mr. Everett 

 in mountain-streams flowing into the Sarawak and Baram Bivers 

 and at Bongon. They differ, however, from the larva above described 

 in having both upper and lower mandible formed of tAvo pieces, 

 separated in the middle line by a considerable interspace ; these 

 horny pieces differ besides in being ribbed and strongly toothed. 

 Somewhat similar larvas, but with the lower mandible formed of 

 a single piece, have been recently described and figured by Mocquard 

 (Nouv. Arch, du Mus. 3, ii. 1890, p. 154, pi, xi. fig. 4) in his paper 

 on tbe Reptiles and Batrachians of Kina Balu and referred by 

 him, rightly I think, to his J.vahts nuhilns (= Rana natatrix, 

 Gthr.). Another larva with ventral disk, and agreeing very closely 

 in the buccal characters with that of R. jerboa and cavity mpanum, 

 was obtained by M. Fea in the Ivakhien hills. Upper Burma, and 

 referred by me to Rana latopalmata, Blgr. (afyhana, Gthr.). I 

 have since found three specimens of the latter larva, from Dar- 

 jeeling, in the late Mr. Day's collection. We are therefore now 

 acquainted with five species with a ventral disk in the larval stage, 

 and all five belong to species of tbe genus Rana in which the 

 toes are fully webbed and the digits strongly dilated. They may 

 be distinguished by means of the following synopsis : — 



