560 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



Usually they are more abundant in temporary ponds and marshy 

 fields than about the larger bodies of water. At Mitchell I found 

 them most abundant during March and April about a temporary 

 pond not more than GO feet in diameter. At this place the noise of 

 their shrill cries was so deafening that it rang in the ears like the 

 clatter of an iron foundry. One night I captured 40 of the frogs at 

 this place in a short time, and after noting the position and abun- 

 dance of the remainder rather carefully, I estimated that there were 

 not less than 200 in the pond. Another pond frequented by them was 

 not more than 200 yards away, and there were many others at short 

 distances. 



They sit about the edge of the water or on a stick or weed or a 

 bit of bark and devote their whole energy to the love song. The 

 gular sac is distended with all the power the frog can command until 

 it almost equals the body of the animal in size. Then, the effort of 

 the animal exhausted, it suddenly collapses, producing a shrill, ear- 

 piercing whistle, which is repeated three or four times in succession 

 as rapidly as the animal can gather the force of its muscles for the 

 act. During this effort the frog seems oblivious to all else. You 

 can throw the brilliant glare of an acetylene reflector upon him, and 

 he does not even turn his head to stare at it. Approach closer and 

 place your hand over him, yet he must give expression to that cry, 

 even though he feels your hand inclosing him in its grasp. 



During the breeding season the Pickering frogs may be heard at 

 all hours of the day, although larger numbers join the chorus in the 

 early evening. At thisseason they may also be seen during the day- 

 time. Later in the summer I did not succeed in finding a single 

 specimen, so thoroughly do they hide when the mating instinct is 

 dormant. 



They have many enemies, who are doubtless attracted, both by the 

 volume of the chorus when the frogs gather in such numbers, and by 

 its excellent carrying power. 1 found the tracks of opossums, rac- 

 coons, minks, and weasels about the pond above mentioned. Larger 

 frogs and also snakes cat them. 



It is difficult to understand how their eggs develop in the tempo- 

 rary puddles which they seem to frequent most. Small masses of 

 eggs, presumably of this species, were found in the pond previously 

 mentioned about the last of March. Some of these hatched, hut two 

 weeks later there was no water, and not even soft mud, in the pond, 

 and the larva' must have been dried up. 



Width of head over tympanum of largest individuals, 10 mm.: 

 tip of snoui to anterior border of tympanum, T; snout to vent, 28; 

 vent to heel. '21 ; vent to tip of longest toe, 42. 



