304 BULKETIN 133, UNITED STATES NATIONAL, MUSEUM 



These flycatchers run about freely on the ground, stopping ab- 

 ruptly to throw up the head, so that they frequently suggest small 

 thrushes. At other times they rest on clods of earth, bushes, or 

 fence posts, from which they dart out at passing insects. Like 

 T aenioytera irwpero^ they suggest in many of their mannerisms the 

 bluebirds {Sialia) of North America. The crenulated lobe encir- 

 cling the eye is easily seen in females, while in males, in which it is 

 larger, its extent and light color produce an effect that is almost 

 uncanny. During the breeding season males frequently rise 3 or 4 

 meters in the air, to whirl over and descend head first, with rapidly 

 vibrating wings that produce a white halo about the body. Occa- 

 sionally one in the same display describes erratic parabolas in the 

 air, that reveal its contrasted colors to the utmost. Not content 

 with these conspicuous displays, it attempts song, a squeaky effort 

 barely audible at 50 meters. At other seasons the birds are wholly 

 silent. 



On November 24 a female was seen near Roca carrying material 

 for nest lining, while at Ingeniero White, the port of Bahia Blanca, 

 two or three broods of fully grown young were seen December 13. 

 These last uttered low, squeaky calls. 



The species is known locally as pico plato^ or more rarely ojo plato, 

 misnomers both since bill and eye are yellow. An adult male, taken 

 July 10, had the bill straw yellow, tipped faintly with duslcy ; rosette 

 about eye baryta yellow; iris barium yellow; tarsus and toes black. 

 A female, shot July 23, had the maxilla and tip of mandible bone 

 brown, becoming blackish at extreme tip; sides of maxilla, behind 

 and below nostril, and base of mandible chartreuse yellow; iris 

 vinaceous buff, with spots and mottlings of a darker color; rosette 

 about eye deep olive-buff; tarsus and toes black. 



LICHENOPS PERSPICILLATA ANDINA Ridgway 



Lichenops perspicillatus andinus Ridgway, Proc. U. S. Nat. Mus., vol. 2, 

 May 22, 1879, p. 483. (Santiago, Chile.) 



An adult male silverbill shot at Zapala, Neuquen, on December 9, 

 1920, is representative of the present race, as the white wing patch 

 is restricted by encroachment of black, especially on the outer webs 

 of the primaries, and the wing has a measurement of 96.2 mm. 

 Females of the two races of Lichenops appear indistinguishable in 

 color, though in andina they average somewhat larger than in true 

 perspicillata. The difference is slight and measurements overlap, so 

 that many specimens of this sex, taken alone, may not be certainly 

 identified. 



On December 8 and 9, 1920, these birds were fairly common in 

 areas where water offered them a suitable haunt. Extensive tracts 



