462 BOULENGER. 



convinced that the Hne of cleavage between the two species corre- 

 sponds to that traced by Howe, who has endeavored to improve on 

 the definitions given by Cope, which are entirely inadequate. 



R. pretiosa, R. cantah rig ends, and R. silvatica are evidently closely 

 related to the three widely distributed European species R. temporaria, 

 R. arvalis, and R. agilis, which they represent in America; but I am 

 inclined to regard this as a case of independent, parallel evolution in 

 the two parts of the world from a common ancestor, of which R. dray- 

 tonii is perhaps the surviving representative. 



15. Rana godmani. 



fLevirana vibicaria Cope, Proc. Ac. Philad., 1894, p. 197. 

 Rana godmani Gunth., Biol. C.-Am., Kept., p. 204, PI. lxiii, fig. A (1900); 

 BouLENG., Ann. and Mag. N. H. (9) III, 1919, p. 411. 



Vomerine teeth in feeble oblique groups between the choanse, 

 equally distant from each other and from the latter, or nearer each 

 other. 



Head slightly broader than long, rather strongly depressed; snout 

 rounded, feebly projecting beyond the mouth, as long as or a little 

 longer than the eye; canthus rostralis obtuse; loreal region feebly 

 oblique, concave; nostril equidistant from the eye and from the end 

 of the snout; distance between the nostrils equal to or a little greater 

 than the interorbital width, which equals that of the upper eyelid; 

 tympanum very distinct, about f the diameter of the eye, 1^ to 2 

 times its distance from the latter. 



Fingers moderate, obtuse or a little swollen at the end, first longer 

 than the second, third as long as or a little longer than the snout; 

 subarticular tubercles moderate. 



Hind limb moderately long, the tibio-tarsal articulation reaching 

 the eye, the heels overlapping when the limbs are folded at right 

 angles to the body; 4^ to 5 times as long as broad, 2t to 2i times in 

 length from snout to vent, shorter than the fore limb, a little shorter 

 than the foot. Toes slightly swollen at the end, f webbed, 2 phalanges 

 of fourth and one of third and fifth free; the web separating the outer 

 metatarsal in third distal half; subarticular tubercles rather small, 

 moderately prominent; no tarsal fold; inner metatarsal tubercles 

 oval, about f the length of the inner toe; no outer tubercle. 



Skin smooth; a broad glandular dorso-lateral fold, as broad as the 

 upper eyelid, from above the tympanum to the hip; the distance 



