262 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



They have a variety of sputtering, scolding calls that they utter on 

 occasion of alarm or interest, and in the spring and summer sing a 

 pleasing little song. A male taken September 15 at Puerto Pinasco. 

 Paraguay, was approaching breeding condition, while near Rio 

 Negro, Uruguay, fully grown young were common during the middle 

 of February. Young in ju venal plumage lack the rufous crown cap 

 of adults but gain it at the post-juvenal molt. In first dress they are 

 browner both above and below and have the wing coverts less bright 

 than after the first molt. In an adult male the maxilla was dull 

 black; mandible gray number 6; iris pecan brown; tarsus and toes, 

 grayish olive. Another differed in that the maxilla and tip of the 

 mandible were blackish slate and the iris cinnamon rufous. 



SYNALLAXIS ALBESCENS ALBESCENS Temminck 



Sijnallaxis albescens Temminck, Nouv. Rec. Planch. Col. Ois., vol. 3, 1838, 

 pi. 227, fig. 2. (Province of Sao Paulo, Brazil.'') 



Birds of this species were recorded at the following points: Re- 

 sistencia, Chaco, July 10, 1920 (immature female taken) ; Las Pal- 

 mas, Chaco, July 16 to 31 (males, July 17 and 31, females on July 

 16, 17, and 28) ; Formosa, Formosa, August 24; Puerto Pinasco, 

 Paraguay, September 3 (adult male) ; Victorica, Pampa, December 

 24 to 29 (males on December 24, 27, and 29, female, December 29). 



The specimens secured are allocated to the typical form without 

 direct comparison with skins from southern Brazil. The small 

 series from Victorica, Pampa, in somewhat worn breeding plumage 

 is slightly grayer than skins secured during winter in the Chaco, 

 but seems otherwise similar. The remainder of the skins taken are 

 quite uniform. Specimens in fresh winter plumage have the rufous 

 color of the crown slightly obscured by brownish tips. 



During the winter months, in the Chaco, this spine tail was 

 abundant in saw grass and bunch grass at the borders of thickets, 

 or in little openings among scattered trees and bushes on the savan- 

 nas. On sharp frosty mornings comparatively few were encountered 

 until about 11, when as the day became warmer these small birds 

 appeared in numbers in brushy pastures where none had been visible 

 two hours before. They flew out with quick, tilting flight to new 

 cover or dodged in and out among the clumps of grass or low 

 branches with quick scolding notes, but seldom paused to perch in 

 the open. Their choice of haunt in fairly open savanna regions 

 was in decided contrast to the habitat of Synallaxis a. frontalis that 

 frequented the spiny growths of caraguata amid denser, darker 



^ Designated by Berlepscb and Hartert, Nov. Zool., vol. 9, April, 1902, p. 59. 



