50 ME. G. A. BOTTLENGER ON THE REPTILES 



3. Rana opisthodon. (Plate X.) 

 Rana opisthodon, Bouleng. Proc. Zool. Soc. 1884, p. 211. 



The vomerine teeth form two oblique series entirely behind the level of the choanse ; 

 they do not extend outwards to the vertical of the inner corner of the latter, and the 

 space between them equals hardly the length of one series. The lower jaw shows no 

 tooth-like processes. The Eustachian tubes are a little larger than the choanse. 



The head is large and semioval in contour ; its length is contained nearly twice in 

 that of the body, and equals or slightly exceeds the length of the nine dorsal vertebrae ; 

 it is a little broader than long. The snout is rounded, sloping gradually, and slightly 

 longer than the diameter of the orbit ; the upper lip hardly projects ; the nostril is much 

 nearer the tip of the snout than the orbit ; the canthus rostralis is not very strongly 

 marked, and slightly curved ; the loreal region is oblique and concave. The eye is of 

 moderate size ; the interorbital space is convex in the large female, plane in the smaller 

 males, and as broad as or a little narrower than the upper eyelid. The tympanum is 

 distinct ; its vertical diameter, which is generally a little greater than the horizontal, 

 equals two fifths to one half the diameter of the eye, or the distance from the orbit to 

 the tympanum. 



The fore limb is of moderate proportions, and resembles that of the preceding species, 

 except that the tips of the fingers are not dilated, but simply blunt. The hind limb is 

 of moderate length ; the tibio-tarsal articulation reaches the eye, and the length of the 

 tibia equals that of the fore-arm and hand. The toes are two thirds webbed, and the 

 tips dilated into small disks ; the web reaches the penultimate phalanx on the inner 

 side of the third toe, and on both sides of the fourth, otherwise attains the distal disks ; 

 the subarticular tubercles are large and oval. The inner metatarsal tubercle is elliptic 

 and flat, and an outer tubercle, if. distinguishable, is small and rounded. No fold 

 along the tarsus. 



In the female specimen the upper surfaces are covered with numerous small, flat, 

 porous warts, which are elongate on the back anterior to the sacrum, rounded on the 

 upper eyelids, the limbs, and the hinder part of the body ; in the males the skin is 

 much smoother, without warts, or with small elongate glandules on the flanks ; a 

 glandular fold limits the temporal region superiorly. The belly and the lower surface 

 of the thighs are slightly granulate, the rest of the lower surfaces being smooth. 



The upper parts are dark brown, with the warts blackish in the female ; in the males 

 they are more olive, with a few dark spots and cross bars on the limbs and vertical bars 

 on the upper lip, and a cross band between the eyes. The hinder side of the thighs 

 with small whitish dots. The lower parts are brownish white, and the throat is entirely 

 light brown. 



The male is provided with two internal vocal sacs. 



