AND BATEACHIANS OF THE SOLOMOJS' ISLANDS. 51 



millim. millira. 



From snout to vent 78 125 



Head 28 46 



Width of head 34 55 



Fore limb 45 77 



Hand 19 31 



Hind limb 112 170 



Foot 36 o5 



Three male specimens from Treasury Island and a female from Faro Island were 

 presented by Mr. Guppy. 



B. opisthodon is well distinguished fr-om R. guppyi by the much shorter lii ibs and 

 the arrangement of the vomerine teeth. From i?. grunniens it is chiefly distinguished 

 by the less oblique and more posterior series of vomerine teeth, the shorter web, and 

 the absence of a tarsal fold. 



This species affords another instance of Batrachians dispensing with regular larval 

 stage, the metamorphoses being hurried through within the egg. Mr. Guppy supplies 

 the following notes : — " Diuing a descent from one of the peaks of Faro Island I stopped 

 at a stream some 400 feet above the sea, where my native boys collected from the moist 

 crevices of the rocks close to the water a number of transparent gelatinous balls, rather 

 smaller than a marble. Each of these balls contained a young frog, about 4 lines in 

 length, apparently fully developed, with very long hind legs and short fore legs, no tail, 

 and bearing on the sides of the body small tufts of what seemed to be brauchisB. On my 

 rupturing the ball or egg in which the little animal was doubled up, the tiny frog took 

 a marvellous leap into its existence, and disappeared before I could catch it. On 

 reaching the ship an horn- after, I found that some of the eggs which I put in a tin had 

 been ruptured on the way by the jolting, and the liberated frogs were leaping about 

 with great activity. On placing some of them in an open-mouth bottle 8 inches long, 

 I had to put the cover on, as they kept leaping out." 



In illustration of this interesting observation, Mr. Guppy sent several ova and recently 

 hatched young, which are to be referred without the slightest doubt to Rana opisthodon. 

 The ovum, which measures 6 to 10 millim. in diameter, is a transparent spherical 

 capsule in which the young frog is coiled up in the same way as figured by Peters' in 

 Hylodes martinicensis ; but none of the specimens, which are in an advanced stage of 

 development, show anything of a tail. There are no gills, but on each side of the 

 abdomen are several regular transverse folds (which in their arrangement remind of the 

 gill-openings of Plagiostomous Fishes), the function of which probably is that of 

 breathing-organs, like the tail of Hylodes. The lip of the snout is furnished with a 



' Mon. Berl. Ac. 1876, p. 714, fig. 2. 

 VOL. XII. — PART II. No. 3. — April, 1886. i 



