238 REPTILES AND BATRACHIANS 



churia to Northern China, while the fourth is restricted 

 to Southern China. The processes of the sacral vertebra 

 are still more strongly dilated than in Discoglossus. The 

 pupil is roundish, triangular, or heart-shaped. The 

 tympanum is absent. The fingers are free, the toes 

 webbed. 



The two European forms, the Fire-bellied Toad, 

 B. igneus, and the Yellow-bellied Toad, B. pachypus, 

 which for so many years were confounded under the 

 specific name of the former, are easily distinguished, apart 

 from the coloration of their under-surfaces, by the length 

 of tibia, which is shorter than the foot in B. igneus, as long 

 as, or longer, in B. pachypus. Males of the former species 

 may be further distinguished by possessing internal vocal 

 sacs, which are absent in the latter. Both toads are quite 

 small, attaining a maximum length of only two inches. 



The Fire-bellied Toad is dark olive or blackish above, 

 while the lower parts are marbled with orange or ver- 

 milion, and black ; a few white spots are sometimes 

 present ; it inhabits the low-lying parts of Russia, west of 

 the Volga, Southern Sweden, Denmark, North Germany, 

 and Austria Hungary, and is never found in hilly districts, 

 where it is replaced by the Yellow-belHed Toad of Central 

 and South-Eastern Europe, from North Brittany to 

 Southern Greece ; in the latter species the lower parts are 

 marbled black and bright yellow. 



Both forms spend the greater part of their existence in 

 the water, but whereas B. igneus is always found in small 

 ponds or pools of clear water, B. pachypus will frequent any 

 sort of pool, clear or dirty, and the writer has frequently 

 caught specimens in small rain puddles in cart-ruts of 

 roads. 



