12 ARKIV FÖR ZOOLOGI. BAND 2. NIO 20. 



440 but also with statements given on the older form Phr. 

 plicatus Gntr. In fact a comparison between the descriptions 

 of the two forms shows that the only difference of any value 

 would })e that the tympanmn should be distinct in Phr. auri- 

 tus but hidden in Phr. plicatus. The tympanum, however, 

 seems in this case to be of shght importance as distinguishing 

 character. being considerably varying at least in all these 

 individuals. While in some examples absolutely invisible it is 

 in others well distinct with well marked margins hmited from 

 the surrounding skin. Thus, with the same right as Bou- 

 LENGER distinguishes Phr. auritus from Phr. plicatus, I could 

 declare these individuals to be two distinct species, which, 

 however, is quite impossible as in this case there are all sorts 

 of individual variations and the specimens in other respects 

 completely agree with each other. 



The only difference, however, beside that of the tympa- 

 num I am able to find in the descriptions of the species men- 

 tioned may be that »the interorbital space is narrower than 

 the upper eyelid» in auritus, but a little broader» in plicatus, 

 a rather slight and valueless specific distinction. Generally 

 the interorbital space in these specimens is narrow^er than the 

 upper eyelid, thus a character which ought to range them 

 under forma auritus, but there are also specimens in which 

 this space is at least equal in breadth to that of the eyelid, 

 and having observed this fact we are not far from the next 

 step »a little broader». 



Thus, my opinion is that Boulenger's Phr. auritus is 

 quite the same as Gunther's Phr. plicatus, on account of 

 which I give the specimens this older name, although in 

 every respect they agree with the description of Phr. auritus. 



In both species mentioned the toes are stated to be two- 

 thirds webbed, which is the case aJso in these specimens, 

 though the membrane as a very slight fold extends as far 

 as the disks. Looking at Boulenger's figure of Phr. auritus 

 we find quite the same. 



Finally, regarding the colour, it varies considerably, in 

 manner described by the authors. The distinct black small 

 spöts on the pelvic region and the white median line, spöken of 

 by Boulenger, exist in a few specimens. Any constant diffe- 

 rence in colour between male and female cannot be stated. 

 In some of the males the throat is more or less black but 



