72 U. S. NATIONAL MUSEUM BULLETIN 206 



wider and turn to heliotrope, with the interstices of the postfemoral 

 ground color deep ochre yellow; forearm and tibia banded also with 

 drab-gray; a black line down the outside of tibia; a plumbeous anal 

 spot edged anteriorly with a narrow black and a white line; heel with a 

 plumbeous black-edged spot, and a lighter one on the elbow; outer 

 surface of tarsus olive-buff faintly mottled with gray, inner surface of 

 tarsus ochre, the webs Ughter, the disks of toes and fingers olive-gray; 

 chin and chest pale olive-buff, belly and lower limb surfaces im- 

 maculate yellow ochre. Iris silvery cream color, the transversely 

 elliptic pupil black. 



A sketch of a very young specimen from Santa Alexandrina shows the 

 upper head, back, forearm, and tibial surfaces to be pale olive-buff, 

 with minute gray dots covering them, and a narrow sepia dorsal line 

 and a few irregular sepia dots on the back; femur salmon-buff, with 

 faint indications of darker crossbars; outer surface of tibia with a 

 sepia line; a sepia patch on elbow, heel, and postanal region; feet and 

 hands suffused with yellow ochre; chin, chest, and belly lilac-gray. 

 Iris cream color. The adult male has a black or gray chin and throat. 



Variations. — In a fine series of 21 grown individuals, there is not a 

 great deal of variation as to structure. The tympanum at its greatest 

 (vertical) diameter is between three-fifths and three-fourths the eye 

 diameter and always appears very distinct. The eye diameter meas- 

 m-es between five-eighths and three-fourths the distance from the eye 

 to tip of snout, and the interorbital width is 1 to 1}^ times that of the 

 upper eyelid. The fingers are webbed from one-half to slightly more 

 than one-third their length, while the toes are one-half to three- 

 fourths webbed. The pattern is quite constant when present but 

 the median dorsal sepia stripe is absent in about one out of five speci- 

 mens. The glandules besetting the dorsal skin are microscopic, so 

 that the back presents a very smooth appearance. The heel some- 

 times has a rather weak dermal ridge, and a tubercle is rarely present. 



Remarks. — The chorus of singing males gives a booming metallic 

 sound which seems at times to come with a regular clanging, like that 

 of a blacksmith beating on an anvil. It begins early in the evening. 

 The nests were seen in Santa Alexandrina, in the city of Rio de Janeiro, 

 and at Covanca, near Jacar^pagud, not far from the city, as well as in 

 Bello Horizonte, Minas Gerais. They were craterlike mud structures, 

 roimd in shape, and perhaps 20 to 30 cm. in diameter, rising 5 to 10 

 cm. from the hoUowed-out center where the eggs are laid. One adult 

 was seen clinging to the edge of a nest, but whether it had just come to 

 breed or was in the habit of "guarding" that particular nesting site 

 I could not tell. In a very small area covered by an artificial pond in 

 the florist's garden at Santa Alexandrina there were almost a dozen 

 nests containing eggs at all the early stages. The nests were appar- 



