178 



FIRST LESSONS IN ZOOLOGY. 



In the spade-footed toad (Figs. 185, 18G) the feet are 

 provided with a horny, spade-like process, which aids the 



FIG. 185. Spade-foot Toad (Scaphiopus). (Natural size.) 



creature in digging, as this species is usually subterranean 

 in its habits, rarely appearing above ground, except in 

 spring to lay its eggs. 



Of the true frogs (Rana) 

 there are numerous species ; 

 of these, the largest is the 

 bull-frog, which makes a 

 deep, hoarse, grunting noise. 

 Smaller and more common 

 species are the pickerel-frog 

 and the marsh-frog. The 

 frogs lay their eggs in round- 

 ish masses in ponds and 

 pools from April to June, 

 according to the latitude. 



Miss Hinckley has de- 

 scribed the habits of the 

 larger tree-toad (Hyla ver si- 

 color, Fig. 187). The eggs 

 are attached from early May till July, singly and in small 



FiG.186. A. inside of adult left foot of 

 spade-foot toad. (Natural size.) B. left 

 foot of young spade at earlier stage 

 of growth. 



