I1YLA. 251 



Sardinia, in Cyprus, in Syria, and in Persia. We 

 have here to deal with a case of colour-dimorphism 

 which is the more striking: from the fact that in most 

 parts of Europe the coloration of the tree-frog, apart 

 from the play of the chromatophores, is so very 

 constant. 



These spotted or striped examples are of further 

 interest in throwing light upon the origin of the 

 curious lumbar marking of the typical form. Elongate, 

 dark, light-edged spots may form a regular series along 

 each side of the back, the last spot meeting at an 

 angle the lateral dark streak, with which it may even 

 sometimes be almost confluent, as is shown on one 

 side in a Sardinian specimen in M. Lataste's collection 

 (PI. XV, fig. 1), and in a Japanese specimen in the 

 British Museum (fig. 5). There is every reason to 

 believe that these examples represent the original 

 form from which the other colour-varieties have been 

 derived, and that the lumbar marking of the typical 

 H. arbor ea is to be looked upon as the remains of a 

 second, upper longitudinal stripe. 



Some specimens (Cyprus) have four stripes or series 

 of spots in addition to the lateral ; others (Japan) 

 have a pair of _l- or >-shaped markings on the 

 scapular region. 



3. Var. intermedia, Blgr. Agrees with the typical 

 form in having a lateral line and a mark on the loin ; 

 but the green extends on the sides of the throat, as 

 in var. meridionalls. This variety was established on 

 a specimen from Bologna and another from Sicily, 

 which are perhaps only mongrels between the typical 

 form and the var. meridionalis. 



4. Var. meridionalis, Bttgr. (perezi, Bosca, barytonus, 

 Heron-Roy er). The green of the upper surfaces 

 extends on each side of the throat, where it gradu- 

 ally vanishes, or involves nearly the whole of the 

 vocal sac ; a dark brown or golden line from the 

 nostril to the eye, usually continued behind the latter, 

 covering entirely or partially the tympanum ; no 



