TAILLESS BATRACHIANS 203 



The Edible Frog, R. esculenta, has also a very wide 

 distribution, occurring throughout the greater part of 

 Europe, Western Asia, and North-West Africa. In 

 England it used to be common in Cambridgeshire, and at 

 the present day it still exists in fairly large numbers in 

 certain parts of Norfolk. As the British specimens agree 

 with a variety common in Italy, the frog is, perhaps, not 



-"^^c^..v-. 



j« I •..X 



f4^' . ^^^'^ 



Fig. 15. — Eggs of Common Frog. 



(^After Boulcnger.) 



indigenous in this country, and it has been suggested that 

 it may have been originally introduced by the monks. 



The snout in this frog is obtusely pointed and projecting 

 considerably beyond the mouth ; the tympanum is one- 

 half to three-fourths the diameter of the eye. The toes 

 are fully webbed. The skin is smooth, but for a few smdl 

 granules on the sides and on the hind limbs ; a lateral 

 glandular fold is constant. The upper parts are usually 

 green, but sometimes brown, olive, uniform or spotted 

 with dark olive or black, and sometimes with a light 

 yellow, green, or blue vertebral stripe ; the hind limbs 

 are usually barred with darker. Blue specimens are 

 occasionally found, but are rare, and are mere individual 

 abnormalities due to the absence of yellow pigment. 



