BIKDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 357 



the Rio Negro, below General Roca, Rio Negro, where an adult male 

 was shot November 27 and others were seen November 30. It re- 

 sembled other related species in actions and in high-pitched call 

 notes, but was shy and retiring. A fully grown young in spotted 

 plumage was recorded November 27. 



The present species, in addition to the black crown, is distinguished 

 from T. rufiventris by the pale color of tarsi and feet. 



TURDUS ALBICOLLIS Vieillot 



Turdus albicolUs Vieillot, Nouv. Diet. Hist. Nat., vol. 20, 1818, p. 227. 

 (Brazil.) 



An adult male was taken September 30, 1920, opposite Puerto 

 Pinasco on the eastern bank of the Rio Paraguay, where the birds 

 were fairly common on the wooded slopes of the Cerro Lorito. At 

 any alarm they flew in to view the cause, and perched with jerking 

 wings and tail, while they called with a robinlike pinip. When one 

 chanced to spy me, however, it dropped in the dense, low cover at 

 once and was lost to view. The one taken had the maxilla and tip 

 of mandible dull black; base of mandible primuline yellow; iris 

 bone brown ; bare eyelid and gape yellow ocher ; tarsus and toes fus- 

 cous. The wing measures 105.2 mm. 



Chubb ^^ has described a Paraguayan form of this thrush as Mervla 

 albicolUs faraguayemis^ from slrins secured at Sapucay, Paraguay, 

 which is said to " differ from the true M. alhicoUis Vieill. in being 

 olive brown above instead of rufous brown, while the gray band 

 across the throat is paler and narrower, and the white on the middle 

 of the abdomen more extended, imparting a whiter appearance." 

 My specimen when compared with a single skin from Brazil of un- 

 certain locality does not bear out these alleged differences, though 

 they may prove evident when suitable material is examined. 



TURDUS AMAUROCHAUNUS Cabanis 



Turdus amaurochalinus Cabanis, Mus. Hein., pt. 1, 1850, p. 5. (Brazil.) 



This robin was recorded and collected as follows: Resistencia, 

 Chaco, July 10 (two males) ; Las Palmas, Chaco, July 13 to 31 

 (adult female, July 30) ; Riacho Pilaga, Formosa, August 6 to 18 

 (adult female, Augu.st 18) ; Formosa, Formosa, August 23 and 24; 

 Cerro Lorito, opposite Puerto Pinasco, Paraguay, September 30 

 (adult female) ; San Vicente, Uruguay, January 30, 1921 (juvenile 

 male) ; Lazcano, Uruguay, February 3 to 8 (juvenile male, February 

 3) ; Rio Negro, L^ruguay, February 17 (adult female) ; Tapia, Tucu- 

 man, April 13 (immature male and adult female). Specimens in 

 juvenal plumage resemble adults in general appearance, but are 



^Ibis, 1910, p. 608. 

 54207—26 24 



