Variation of the Edible Frog. 243 



S on the other, and one (from Vienna) has but a single tooth. 

 3 to 5 is the usual number in the var. chinensis. The 

 series of teeth jire usually nearer to each other than to the 

 choanse, but they are sometimes equidistant in the typical form 

 and the var. ridibunda and usually so in the var. saharica ; 

 an arrangement such as is represented on the figures in 

 Schreiber's book* I am sure never occurs. In a female 

 from Cadillac, Gironde (var. ridibunda) the teeth form long-, 

 slightly curved series, extending almost right across the 

 space between the choanal. The series are sometimes hori- 

 zontal, sometimes more or less oblique though seldom very 



Fig-. 1. 

 a li 



© <5> 



"SS £?■ 



%<£? 



d e f 



Vomerine teetli in specimens fro.n St. M.ilo (a, li), Cadillac (c), 

 Basle (dj, Oporto (ej, and Dead Sea (f). 



much so ; a male from St. Malo has the series oblique on 

 the right side, horizontal on the left. The teeth are usually 

 exactly between the choanse, but they may extend backwards 

 beyond a line connecting" the posterior borders of the latter, 

 or, more exceptionally, they may be on a line with their 

 anterior borders (specimens from Oporto and Pekin). There 

 is no difference whatever in the disposition of the vomerine 

 teeth that could help in the definition of the various forms 

 of R. esculenta. 



The Tongue. 



The tongue varies much in size : it may nearly cover the 

 floor of the mouth or its width may be only about one-third 

 that of the latter. Bedriaga "f" has already mentioned that 

 the posterior processes .also vary much in length according 



* ' Herpetologia Europaea/ 2nd ed. (1912). — So much in this book is 

 merely careless compilation that I need not further allude to it except 

 to express amazement at the suggestion there made that the Spanish- 

 Portuguese frogs named vars. h : spanica and pevezi may be the same as 

 the var. lessojice ; also at reading that the males of H. yrceca and 

 It. iberica are distinguished from those of allied species in having 

 external vocal sacs. 



t Lurchfauna Europa's, i. p. 36 (1891). 



19* 



