BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 263 



thickets. In a way the areas inhabited by the two are reflected in 

 their tone of plumage, the bird of the grass ckimps being paler than 

 the one that frequents the darker forest border. S. a. albescens was 

 gregarious, so that a number w^ere found together, often in mixed 

 flocks with little groups of finches. It w^as not unusual to find them 

 in tall grass in wet localities rather distant from protecting shrub- 

 bery. 



At Victorica, Pampa, albescens was of different habit, as here it fre- 

 quented the bushes and low trees that formed a heavy ground cover 

 in the open, scrubby forest. Toward the end of December the birds 

 had completed breeding and were encountered in little parties that 

 comprised adults and young. They were social and searched rather 

 quietly through the limbs, often in close proximity to one another. 

 Though quiet and deliberate in movement they clambered rather 

 actively through the thorny twigs, always under cover. They ranged 

 here from 1 to 10 meters from the earth, and were not found feeding 

 on the ground. This difference in habit from what I had observed 

 in the Chaco led me to suppose that the birds from Pampa were dif- 

 ferent, but such does not seem to be the case. 



In a female, taken July 10, the maxilla was blackish brown number 

 1 ; mandible mineral gray ; iris honey yellow around pupillar open- 

 ing, becoming lighter toward outer margin; tarsus and toes deep 

 grayish olive. 



SYNALLAXIS ALBILORA Pelzcln 



Synallaxis alMora Pelzeln, Sitzungsb. Math.-Nat. CI. Kais. Akad. Wiss. 

 (Wien), vol. 20, 1856, p. 160. (Cuyaba.) 



Near Kilometer 80, west of Puerto Pinasco, Paraguay, on Sep- 

 tember 16, 1920, I found one of these birds in heavy, low forest 

 perched on a stick nest as large as a hat, while its mate hopped about 

 in heavy brush near by. Attention was drawn to the pair by the 

 curious song of the bird at the nest tas pit taho we^ a peculiar suc- 

 cession of notes with rather slow nasal cadence. Both birds were 

 slow and deliberate in their actions. 



In the adult female the maxilla was black ; mandible gray number 

 6 ; iris liver brown ; tarsus neutral gray and toes storm gray. These 

 birds may represent a new form, as the skin preserved is somewhat 

 paler, less rufescent below than the average of a small series in the 

 American Museum of Natural History from Matto Grosso, Brazil. 

 The species is known from Brazil and Bolivia, but does not appear 

 to have been recorded previously from Paraguay. Measurements 

 of the bird secured are as follows: Wing, 58; tail, 74.5; culmen from 

 base, 12.8; tarsus, 21.3 mm. 



