THE DISC-TONGUED FROGS 2651 



described, the tadpoles, after shedding the external gills, differ in having the 

 breathing pore situated in the middle of the under surface of the body, instead of 

 on the left side. 



From the painted frog {Discoglossus picttts) of Southern Europe and 

 Northwestern Africa, which alone represents the typical genus of the 

 family, the fire-bellied frog (Bombinator igneus), represented in the 

 figure on p. 2622, is distinguished by the absence of an external tympanic mem- 

 brane to the ear; while it is further characterized by the adherent tongue, the 

 triangular form of the pupil of the eye, and the great expansion of the extremities 

 of the transverse processes of the sacral vertebra. This frog, which inhabits 

 Europe and Asia, although unknown in the British Islands, has the skin very warty 

 on the upper parts, while beneath it is nearly smooth. In color it is olive above,, 

 with or without black marblings; beneath it is orange or yellow, marbled with 

 black. The males are devoid of a vocal sac, but during the breeding season they 

 develop black rugosities on the inner side of the fore-arm, as well as on the inner 

 tubercle of the metacarpus, and on the two innermost front-toes. There are two 

 varieties of this frog (reckoned by some as distinct species) of which the one with 

 orange colored under parts is to be found in streams or marshes in the lowlands, 

 while the yellow-bellied form lives at considerable elevations in the mountains. 

 They are essentially aquatic frogs, only leaving the water for a short time in the 

 spring, when they may be seen hopping on the land on their long hind-legs. In 

 the w 7 ater they generally take up their position at some distance from the bank, 

 sitting with their heads slightly raised above the surface, and disappearing with 

 lightning-like speed at the slightest noise, to seek safety in the mud at the bottom. 

 The tadpoles grow to an unusually large size, and are especially characterized by 

 the great development of the tail fin. 



The third European representative of the family is the so-called 

 s midwife frog (Alytes obstetricans} of which the typical form inhabits 

 France, Switzerland, Belgium, and Western Germany, while a variety occurs in 

 Spain and Portugal; Spain being also the home of the second member of the genus 

 {A. dsternasit). From the fire-bellied frog these two species are distinguished by 

 the distinct external tympanic membrane to the ear, the elliptical andvertical pupil 

 of the eye, and the moderate expansion of the transverse processes of the 

 sacral vertebra. The common species has the skin of the upper parts warty, 

 while that of the under surface is granular; the glands near the head are 

 small or indistinct, but there are large ones on the limbs; and the males have no 

 vocal sac. The color of the upper parts is olive gray, with darker dots and irregu- 

 lar spots. Essentially an aquatic species, this frog derives its name from the cir- 

 cumstance that the male takes charge of the eggs during their development. The 

 breeding season lasts for upward of six months, namely, from March to August, 

 although the eggs are laid only from March till June. These are deposited by the 

 female in the form of long chains, which may be upward of a yard and a half in 

 length. These chains are taken by the male, and wound round his legs and thighs; 

 and when thus loaded he retires to some burrow or convenient hollow near the 

 bank, where, at least during the daytime, he remains in concealment until the tad- 



