BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 353 

 MIMUS PATAGONICUS PATAGONICUS (d'Orbigmy and Lafresnaye) 



Orpheus patagonicus d'OEBiGNY and Lafresnaye, Mag. Zool., 1837, cl. 2, 

 p. 19. (Patagonia.) 



Two males and a female of the Patagonian mocking bird, in 

 slightly worn breeding dress, secured at General Roca, Rio Negro, 

 November 24 and 29, 1920, show the normal development of grayish- 

 brown ventral surface and cinnamon-buff flanks that characterize 

 the species. One when first killed bad the bill and tarsus black; 

 iris buffy brown. 



This mocker was common in growths of atriplex {Atriplex lampa 

 and A. crenatifoNa) , creosote bush, and greasewoods on the flood 

 plain of the Rio Negro, near General Roca, and proved to be a true 

 desert form since it spread out through the arid, gravel hills north 

 of the railroad, where water was wholly lacking. On December 

 6 it was recorded from the train near Challaco, Neuquen (approxi- 

 mately 100 kilometers west of the town of Neuquen), but was not 

 found at Zapala. 



These mockers watched alertly from the tops of bushes, or flew 

 ahead of me, showing a band of white, interrupted in the middle, 

 at the end of the tail. Their song, mockerli^'e in type, delivered 

 from some low perch, consisting of many broken phrases interspersed 

 with frequent imitations of the notes of other brush birds, was 

 similar to that of 31. triianis, though the performers were less flam- 

 boyant in actions during delivery. 



MIMUS PATAGONICUS TRICOSUS Wetmore and Peters 



Mimus patagonicus tricosns Wetmore and Peters, Proc. Biol. Soc. Wash- 

 ington, vol. 36, May 1, 1923, p. 145. (Lujan de Cuyo, Province of 

 Mendoza, Mendoza.) 



The present form is separated from typical patagonicus by its 

 grayer dorsal surface, a difference most evident in birds in fall and 

 winter plumage. 



Two were observed near an old puesto above the city of Mendoza, 

 on March 15; and in the foothills of the Andes near Potrerillos, 

 Mendoza, the birds were common from March 15 to 19. An imma- 

 ture male, taken at El Salto, at an elevation of 1,800 meters, on 

 March 19, is in post -ju venal molt. 



MIMUS THENCA (Molina) 



Turdus Thenca Molina, Sagg. Stor. Nat. Chili, 1782, p. 250. (Chile.) 



Near Concon, Chile, M. thenca Vv'as common from April 24 to 28, 

 1921, and two specimens were taken. This species seems closely 

 allied to M. longicaudatus Tschudi ** of Peru, which may prove sub- 



"Arch. fur Naturg., 1844, p. 280. (Peru.) 



