114 INTIiODUCTION. 



by V. Mehely that, in the few localities where the two 

 species co-exist, intermediate specimens occnr which 

 are no doubt to be regarded as hybrids. 



As to the supposed hybrids between L'nvaesciderda 

 and temjjoraria, noticed by Schlotthanber and others, 

 they are nothing but Z?. arvalh, a species which is in 

 many respects intermediate between the two supposed 

 parents, and with which the authors in question do 

 not seem to have been well acquainted. 



Hybrid embryos between Rana csculcnta and /?. 

 arvcdis appear to have been recently obtained by W. 

 Gebhardt. 



So-called hybrids between Hyla arbor ea and li. 

 meridunialis (hary tonus), and Biifo virnVis and B. 

 arabicns, obtained by Heron-Royer, are only mongrels, 

 as I do not consider the specific distinctions justified. 



