198 VERTEBRATE ZOOLOGY 



firmly adherent." The eggs then sink into pockets in the skin. Each 

 pocket develops a sort of hinged lid, which the young toad pushes 

 open from time to time, as in Fig. 1 14, A. The habits of the African 

 Aglossa are less specialized and have no features of especial interest 

 for the general student. 



SUB-ORDER 2. PHANEROGLOSSA (TONGUED ANURA) 



There are seven families of these frogs and toads and only the most 

 general distinguishing characters of these groups can be given. As in 

 any other group that has undergone pronounced adaptive radiation, 

 the chief points that interest the student are the special structural 

 adaptations and peculiar habits. Under each family only the best 

 known and most interesting species will be described. 



Family 1. Discoglossidce. The tongue is disk-shaped and non- 

 protrusible; the vertebrae opisthocoelous; the upper jaw and vomers 

 have teeth; and the male has no vocal sac. 



Bombinator igneus, the "fire-bellied toad," is a poisonous form with 

 pronounced warning coloration and a special method of displaying it. 

 The under surface is colored a purplish black with conspicuous orange- 

 red patches. They are decidedly aquatic, floating at the surface with 

 legs extended so that the conspicuous color is well displayed to all 

 aquatic enemies. They also rest on land and when surprised there 

 they make a strong effort to bring the under surface to view 

 by turning the legs over the back and throwing back the head as in 

 Fig. 114, B. Besides their coloration they are interesting because of 

 the weird noises they make. The voice is described as like "hoonk, 

 hoonk" or "ooh, ooh," and the males join in a mournful concert of 

 sound during the breeding season. 



Alytes obstetricans (Fig. 114, C), the "midwife-toad," is in general 

 appearance quite ordinary. It occurs in France and Switzerland. 

 The interesting feature of the species is the method of caring for the 

 eggs by the males and the latter ? s odd habit of relieving the female of 

 her eggs. The male assiduously massages the cloaca of the female 

 with the paws. After a considerable time the female suddenly and 

 with great apparent effort expels the eggs all in a bunch. The male 

 then clings to the female 's head and fecundates the eggs, after which 

 he carries the bunch of eggs off with him, attached to the hind legs, 

 to a hole in the ground. He moistens the eggs with dew and occasion- 

 ally takes them into the water with him. When the eggs are nearly 



