144 BULLETIN 58, UNITED STATES NATIONAL MUSEUM. 



I have not alluded to Kiihl's own application of RhacopJiorus in 

 1822," because it was certainly unidentifiable at the time. He refers, 

 it is true, to the dermal flap at the heel,'' but in so uncertain a way that 

 the genus without reference to a described or figured species (and no 

 species was described until twenty-five years afterwards) must have 

 been completely unintelligible. The fact that we know now what he 

 meant is not sufficient. 



Polypedates, or Poly pedotes, Buergeria, and Theloderma were proposed 

 by Tschudi simultaneously for two different species of the same genus, 

 Theloderma being mentioned first. Dumeril and Bibroii, however, in 

 184f , in combining the first two genera, selected Polypedates for the 

 greater group, and Guenther, in 1887, merged Theloderma in Poly- 

 pedates, hence this name must be adopted according to article 28 of the 

 International Zoological Code of Nomenclature. 



The genus Polypedates, as here understood, differs from the genus 

 Rana chiefly in the presence of a small bone intercalated between 

 the last phalanx of the digit and the normally penultimate one. 

 T^xternall}^ this arrangement is marked on the upper surface by a 

 kink or notch just before the widening of the disk, thus rendering 

 dissection in most cases unnecessary. However^ it is much safer to 

 dissect, as shown by the erroneous reference of Rana ijimse and Rana 

 ishikawse to the present genus. 



KEY TO THE JAPANESE AND FORMOSAN SPECIES OF POLYPEDATES. 



a^ Fingers considerably webbed; color above green (blue or purj)lish in alcohol), 

 immaculate. 

 h^ A distinct outer metatarsal tubercle; dermal margin of fingers much nari'ower 



than the bone P. schlegelii, p. 145. 



b- No outer metatarsal tubercle; dermal margin of fingers equaling the bone in 

 width, 

 c ' Distance from tip of coccyx to end of sacral diapophysis equals the width of 



the head P. viridis, p. 147. 



c^ Distance from tip of coccyx to end of sacral diapophysis much less than width 



of head P. oicstoni, p. 149. 



a^ Fingers free, or with only a rudiment of web at base; color above brownish, more 

 or less marked with darker. 

 h ^ Tibia about one-half the length of head and body, 

 c ^ Vomerine teeth in two long straight series between the choanse, each series 



considerably longer than interval between them P. buergeri, p. 150. 



c ^ Vomerine teeth in two small oval series, each series considerably shorter than 



the interval between them P. eiffingeri, p. 153. 



b " Tibia more than one-half the length of head and body. 



c' Interorbital space narrower than upper eyelid; tympanum less than one-half 



the diameter of the eye P. japonicus, p. 155. 



c^ Interorbital space wider than upper eyelid; tympanum more than one-half 

 the diameter of the eye P. leuconiystax, p. 157. 



a Isis, 1822, p. 476. 



^This dermal heel flap is also found in Hyla palviata, and consequently is not 

 diagnostic. As a matter of fact, the latter species being the only one known at the 

 time, the genus was at first restricted to it, as shown above. 



