518 COLLEGE ZOOLOGY 



Suborder i. AGLOSSA. There are only a few toads in this 

 suborder; all of them are tongueless and belong to the family 

 AGLOSSID^E. Pipa americana inhabits the northern portion 

 of South America; Hymenochirus bcettgeri and Xenopus lewis 

 are confined to Africa. 



The Surinam toad, Pipa americana (Fig. 434), has a peculiar 

 method of carrying its eggs. They are placed on the back of 

 the female during copulation, are held there by a sticky secre- 

 tion, and are gradually enveloped by the skin. Within the 



FIG. 434. The Surinam toad, Pipa americana. (From Mivart.) 



epidermal pouches thus formed the eggs develop and the tadpole 

 stage is passed ; then the young toad escapes as an air-breathing 

 terrestrial animal. 



Suborder 2. LINGUATA. Most of the frogs and toads are 

 included in the six families of this suborder. 



Family i. PELOBATID.E. There are about twenty species, 

 called spade-foot toads, in this family. One genus, Scaphiopus, 

 with four species, occurs in North America. The spade-foot 

 toads are burrowing AMPHIBIA, and usually have thick hind feet 

 provided with a sharp spur for digging. The spade-foots of 



