HERPETOLOGY OF JAPAN. 98 



KEY TO THE GENERA OF JAPANESE FROGS. 



a' Distal and j^eiiultiniate phalanges of digits continuous, withoiit any kink separating 

 them, there being no bone intercalated between them;« (species occurring in 

 Japan proper have tips of digits simple, without regular disks) Rana, }:>. 95 



a^ A well-defined kink, or transverse notch, on uj^per surface of digits between the 

 distal and penultimate phalanges, due to an intercalated small bone;« (tips of 

 digits with large disks) Polypedates, p. 143 



Genus RANA'> Linnaeus. 



1758. Rana Linnaeus, Syst. Nat., 10 ed., I, p. 210 (type, R. temporaria); 12 ed., 



1706, I, p. 354. 

 1814. Ranaria Rafinesque, Specchio Sci. (Palermo), II, fasc. 7 (substitute name 



for Rana). 

 1843. Pelophylax Fitzinger, Syst. Rept., p. 31 (type, Rana escuknta). 

 1891. Crotaphitis Schulze, Jahresber. Naturw. Ver. Magdeburg, 1890, p. 176 



(type, Rana temporana). 

 1891. Baliopygus Schulze, Jahresber. Naturw. Ver. Magdebiu-g, 1890, p. 177 



(type, Rana escuknta). 



Only such synonyms are here enumerated as refer directly to 

 Japanese species or are additional to those quoted in recent syno- 

 nymies. 



The numerous species may be identified by the following : 



synopsis of the species of rana' recorded from japan and adjacent territory. 



a' A distinct dorso-lateral fold. 

 6' Heels not overlapping. 

 d Vomerine teeth between choanse. 



(/' Dorso-lateral fold narrower than interorbital space; numerous distinct longi- 

 tudinal ridges between folds R. nigromaculata, p. 94 



d~ Dorso-lateral fold as broad as interorbital space; no longitudinal glandular 



ridges between dorso-lateral folds R. plancyi, p. 101 



c^ Vomerine teeth behind choanae R. oHnavana, p. 102 



b" Heels overlapping. 



c'- Tips of digits without regular disks. 



(/' Hind legs twice as long as head and body R. longicrus, p. 104 



(P Hind legs much less than twice as long as head and Ijody. 

 e^ A very prominent knob, rudiment of pollex, on inner side of first finger. 



R. holsti, p. 105 

 e^ No prominent knob (not to be confounded with copulary excrescences) on 

 inner side of first finger. 

 /^ Snout long, pointed, distance from orbit to tip of snout longer than width 



between black stripes at anterior border of orbit R. japonica, p. 107 



/- Snout short, blunt; distance from orbit to tip of snout not longer than 

 width between black stripes at anterior border of orbit. 

 g^ Vomerine teeth between choana?, only their posterior end projecting 



backwards beyond them; webs large R. temporaria, p. 113 



g'^ Vomerine teeth behind level of choanse, or nearly so; webs between 

 toes small. 



h^ Inner metatarsal tubercle rather large R. tsushimensis, p. 116 



h^ Inner metatarsal tubercle small R. amurends, p. 119 



c- Tips of digits dilated into distinct disks R. ijimx, p. 121 



olt is well not to rely upon the "kink," but to ascertain the presence or absence of 

 the intercalated phalanx by dissection. 

 b Latin name for frog. 



