BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 203 



sus, 15.2 mm. Specimens of griseus from the type locality are not 

 at hand, but a bird from the Para River is assumed to represent the 

 typical form. The bird from Paraguay is very similar to it in size, 

 and in color pattern differs only in having slightly heavier black 

 streaks on the under tail coverts. For the present, therefore, Capri- 

 mulgus cornutus Vieillot must be considered as a synonym of Nycti- 

 hius g. griseus. Examination of a small series of potoos seem to show 

 that, like many of the Caprimulgidae, they have two types of colora- 

 tion, one dark and more or less rufescent, and the other pale and 

 gray, a fact that makes the proper designation of geographic races 

 difficult. Skins from Peru and Ecuador referred doubtfully by Mr. 

 Ridgway to cornutus^- are larger and darker than the specimens 

 mentioned from Brazil and Paraguay. Whether they represent an 

 unnamed form or whether they should be referred to the bird from 

 Panama, which they resemble closely, it is not possible at present to 

 decide. 



The female shot September 30 in Paraguay had the bill black; 

 margin of mandible vinaceous buff; iris deep chrome; tarsus and 

 toes drab. 



Family CAPRIMULGIDAE 



THERMOCHALCIS LONGIROSTRIS (Bonaparte) 



Caprimulgus longirostrls Bonaparte, Journ. Acad. Nat. Sci. Philadelphia, 

 ^ vol. 4, pt. 2, no. 12, 1825, p. 384. (Brazil.") 



South of Tunuyan, Mendoza, on March 27, 1921, a male of this 

 species flushed with a chattering, whistling call among low bushes 

 on a sandy hill slope, and darted swiftly and erratically away to 

 drop to fresh cover. As it rose a second time it was secured. The 

 large white wing patches give a resemblance to Chordeiles when the 

 bird is on the wing. Another was seen April 8, near Tapia, Tucu- 

 man, in dry forest on a steep rocky slope. 



On an evening in mid-October one of these birds flew from tree 

 to tree along the Avenida de Mayo, in the heart of the business 

 district of Buenos Aires, an individual that had become bewildered 

 during migration. At Lavalle on November 12, 1920, I was taken 

 to view a curious bird, described as " possessing a moustache like 

 a Christian," that had been captured in a garden about three weeks 

 ago, to find that it was the present species. According to popular belief 

 a feather of this bird was a potent love charm, and the fortunate 

 owner of the bird had been charging 10 centavos for a view of the bird 

 to those of the populace whose curiosity regarding the anomalous 

 creature was uncontrollable, while feathers retailed at a peso each, 



^ Birds North and Middle America, vol. 6, 1914, p. 587. 



8» Bonaparte described his bird as from South America without knowu locality, but 

 Brabourne and Chubb, Birds of South America, 1912, p. 101, cite " Brazil " without 

 comment. 



