520 



COLLEGE ZOOLOGY 



Hyla verslcolor is the common tree-frog. It is about two 

 inches long and has the power of slowly changing its color from 

 white to stone-gray or brown and from white to green. These 

 changes usually produce such a perfect harmony between the 

 frog and its surroundings that the animal becomes practically 

 invisible. The eggs are laid in May. They are attached in 

 groups to plants at the surface of the water. 



Hyla pickeringii, the spring peeper, has the discs on the 

 fingers and toes so small that they are scarcely discernible. 



FIG. 435. Brooding tree-frog, Nototrema, female, from Venezuela. In posterior 

 part of trunk is opening of brood-pouch. (From Davenport's Zoology.) 



Acris gryllus is called the cricket-frog. Chorophilus nigritus, the 

 swamp tree-frog, has fingers and toes with minute discs. The 

 brooding tree-frog, Nototrema (Fig. 435), of Venezuela, has a 

 pouch with an opening in the hinder part of the trunk in which 

 the eggs are placed and the young are reared. 



Family 4. CYSTIGNATHID^E. - - This family contains almost 

 as many species (over one hundred and fifty) as the family 

 HYLID^:, but only three species occur in North America. 

 Litliodvtes latrans and Syrrophus marnockii have been recorded 



