574 MR. G. A. BOULENGER ON THE [Dec. 2, 



Cambridgeshire, and Stow Bedon and between Thetford and Scoulton 

 in Norfolk), and generally regarded as introduced from France and 

 Belgium, belongs to the Italian form, R. esculenta lessonce; and 

 concluded by expressing the hope that descendants of the typical 

 R. esculenta, which was introduced in great numbers into Norfolk 

 by Mr. G. Berney forty years ago, would be discovered. Through 

 the kindness of Lord Walsingham, W. Amhurst Amherst, Esq., M.P., 

 and Geo. E. Mason, Esq., who took an interest in the question, I 

 have received much information and additional material this summer; 

 and, what is more important, the typical R. esculenta has been 

 found in or near some of the places where specimens were turned 

 out by Mr. Berney, but where they remained unnoticed, or were 

 confounded with the form lessonce, the introduction of which is 

 clearly of a much older date. The result is the addition to the 

 British fauna of a new form of Frog. If I say " form," and not 

 "species," it is because the limits of these forms are difficult to esta- 

 blish when the whole Palsearctic range is taken into consideration ; 

 but so far as England is concerned, the two forms are as distinct as 

 many generally accepted " species." I may even add that, according 

 to the definition of the genera Rana and Pyxicephalus (Hoploba- 

 traclius) admitted by many authors, Rana esculenta lessonce would 

 fall into the latter ; but I have elsewhere expressed my objections 

 to the validity of the genus Pyxicephalus. 



Soon after the publication of my note in the ' Zoologist,' I re- 

 ceived from Lord Walsingham seven specimens from Stow Bedon ; 

 and on July 29 I had the pleasure of accompanying his Lordship on 

 an excursion to that place, on which occasion twelve more specimens 

 were captured. The Frogs were very abundant at Stow Bedon, in 

 small pools and pits, which, owing to the excessive drought, contained 

 but little water. They did not indulge in their sonorous croaking 

 on the occasion of our visit, and no tadpoles or spawn were to be 

 seen. However, one full-grown tadpole was dredged from the 

 bottom of a pit, but was so much injured that I could not preserve it. 

 I was rather surprised to find that none of the specimens presented 

 that beautiful green colour which is usual in R. esculenta ; all were 

 olive-brown, spotted and marbled with black, and provided with a 

 pale yellow or pale green vertebral line ; all had the enormous meta- 

 tarsal tubercle. This accounts for the fact for which I always was at a 

 loss to find an explanation, viz. the silence of the first discoverers 

 of the Edible Frog in Cambridgeshire as to the green colour which, 

 among other characters, so well distinguishes that species from the 

 Common Frog. R. esculenta lessonce, as occurring in England, is never 

 green. Lord Walsingham informed me that he was making inquiries 

 among the people of that neighbourhood as to how long the Frogs 

 had lived there, and that he had been assured that their existence 

 could be traced as far as sixty years back. Lord Walsingham also 

 inquired of Mr. G. Berney whether the Edible Frog had maintained 

 its existence in Hockering, and was informed that for years past not 

 one had been seen anywhere in that neighbourhood. 



On a request made by Lord Walsingham to Mr. Amhurst Am- 

 herst, I received from that gentleman on August 9 two fine living 



