BATRACHIA. 



341 



these genera have the digital dilatations apparently like those of tree frogs, but they 

 are supported by T-shaped phalanges, as in Hylodes. In Prostlierapis they are divided 

 into two lateral lobes by a longitudinal fissure on the upper side^ 



The Asiatic and African types of arboreal Ranidae' have the dilatations of the toes 

 supported by Y-shaped phalanges, with the sole exception of the African genus 

 Ilylambates, which have the ball and claw form of the Hylidse. The largest and most 

 brilliantly colored of the old-world tree-frogs belong to the genus Mhacophorus. In 

 some of the species of the Malaysian islands the webs connecting the fingers and 

 toes are so large as to form, when extended, parachute-like supports to the animal 

 when leaping from tree to tree in the air. A related genus is the African Chiro- 



Fig, 204. — Hhacophorus reinhardtU. 



mantis, where the toes of the hand are opposable, two against two. Ixalus is a genus 

 widely distributed in Asia, which includes generally small species, all Avithout teeth 

 on the roof of the mouth. Myperolius is a somewhat similar genus, also without 

 vomerine teeth, which is distributed everywhere in Africa where there is vegetation. 

 Many of the sjaecies are brilliantly colored. 



There are over one hundred and ten species of the genus Rana. Some of them 

 have digital dilatations, and are arboreal in their habits. Others have smaller dila- 

 tations and are terrestrial. The typical species are aquatic, or live on the edge of the 

 water, in which they take refuge on the approach of danger. Most of the species are 

 remarkable for the length of the leaps they can make, and the aquatic forms are equally 

 expert swimmers. The largest species is the North American bull-frog, Eana cates- 



