TAILLESS BATRACHIANS. 



Fig. 27 



39 



Ceratoph-ya cornuta (Horned Frog), 



British Isles. The largest species is the Agua Toad {Bu/o marinus) 

 of South America, which attains to a length of 8 inches, the limbs 

 not included, and which possesses enormous parotoid glands. 



The Hylida, or true Tree-Frogs, resemble very closely the 

 arboreal Ranidce as regards form and habits j but the structure of 

 their skeleton proves their affinity to the Toads, from which they 

 are distinguished by the presence of teeth in the upper jaw. The 

 large Tree-Frog exhibited, Hyla doUchopsis, from New Guinea, and 

 the common European species, Hyla arborea, are examples. Closely 

 allied to Hyla is Nototrema (fig. 28), a marsupial Frog provided 

 with a dorsal pouch, into which the ova are introduced (probably 

 by the male) immediately after they are laid, and preserved from 

 injury until hatched. The commonest species, N. marsupiatum, 

 is a native of the Andes of Ecuador, The species of Phyllo- 

 medusa, or " quadrumanous " Frogs, are still more strongly 

 adapted to arboreal life, the first digit of both hands and feet 

 being opposable to the others, like the thumb of the hand. 

 Several species are known from tropical America. 



