HERPETOLOGY OF JAPAK. 183 



by him. Not that the two forms are not (hstiiict. On the contrar}', 

 there are quite a number of distinctive characters, but it is exceedingly 

 difficult to express them in words and it is doubtful whether there is 

 any single character whicli will separate the two forms in all cases. 



'Boulenger found the difl'erence to be chiefly one of proportions 

 and coloration. He stated" that J. polygonata "differs in having 

 the tibia constantly shorter than the skull, fewer labials as a rule, 

 and in coloration," the inference being that in J. swinTionis the tibia 

 is constantly at least as long as the skull. Unfortunately, however, 

 the inference is not borne out by our material, since in several of the 

 Formosa specimens of J. swinhonis, thus inU.vS.N.M. Nos. 34084 and 

 34089, both old males, the tibia is decidedly shorter than the skull, 

 as much so as in several Ishigaki shima specimens. It is true, never- 

 theless, that the Formosan form has the hind limbs longer as a rule, 

 and this is more especially marked when we examine specimens of 

 the male sex, since the females as a rule are somewhat more short- 

 legged. /. swinhonis has a relatively longer fourth toe, the latter 

 extending farther beyond the third than in J . polygonata, but the 

 difference is so small that it defies a definite expression which would 

 make it possible to use it as a critericni in a " key " for identification. 

 A better result is obtained if we compare the length of the fourth toe 

 (without claw) from the base of the third with the distance from the 

 center of the eye to the tip of the snout. In most cases /. sivinhonis 

 has the fourth toe decidedly longer than this distance, while in J. 

 2)olygonata it is usually equal or smaller. 



The number of supralabials offers no tangible diagnosis. There 

 are 7 or 8 labials in about e([ual proportion among over 20 Ishigaki 

 shima specimens, not one with six. 



The coloration furnishes possibly the best distinction, at least 

 among the adults. While there are several of the adult males of the 

 Ishigaki specimens which show a whitish lateral band quite distiiictly 

 and thus differ from the uniform green color of some of the Okinawa 

 adult males, there is one color character in which all the old Formosan 

 specimens agree, viz, in having the throat dark with large distinct 

 white spots. This pattern is not found in au}^ of our Riu Kiu speci- 

 mens in which the throat is whitish more or less sufl'used with rust- 

 red, uniform in the males but in the females marked with irregular longi- 

 tudinal dusky lines converging posteriorly. In the latter there is also 

 a more or less conspicuous longitudinal ])ale line under the eyes 

 parallel with the upper lip, while in the Formosan s])e('imens there are 

 distinct blackish lines running from the eye to the lip. 



There are several other minor ciuiracters oi more or less constancy 

 which are real enougli though hard to express. Thus, the outline of 

 the head is somewhat different especially when viewed from below, 



"Proc. ZdoI. Soc. London, 1887, p. 146. 



