BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 227 



fallax Boiircier, as not applicable to T, chionogaster Tschudi, which 

 he says should probably be placed in T alo phoriis ]Mulsant. 



The two or three individuals of this species seen were observed at 

 the flowers of a common red-flowered epiphyte {Psittacanthns cunei- 

 folius) that was attractive to other hummers in the region. They 

 hovered with humming wings in order to probe the long tubed 

 blossoms, and at short intervals paused to rest on some convenient 

 perch. Their call note was a low chit chit suggestive of that of 

 SappJiO. 



One of the birds when taken had the base of the mandible deep 

 Corinthian red, and the remainder of the bill and the feet black. In 

 the other the base of the mandible was vinaceous fawn ; maxilla and 

 tip of mandible black ; tarsus and toes aniline black. 



The plate in Tschudi's work on which the species is depicted was 

 made previous to the writing of the text as it is lettered Trochilus 

 leucogaster^ a name proposed for another hummer, so that in the text 

 change was made to chio nog aster. No definite type locality is given 

 by Tschudi so that Peru is assumed. 



HYLOCHARIS CHRYSURA (Shaw) 



Trochilus clirysxirus Shaw, Gen. Zool., vol. S, pt. 1, 1812, p. 335. (Para- 

 guay.) 



Four specimens of this interesting hummer were taken as follows : 

 A female at the Kiacho Pilaga on August 14, 1920, a female at Kilo- 

 meter 25, a male at Kilometer 80, and a second male on the Rio 

 Paraguay near Puerto Pinasco, Paragiia} , on Sej)tfmber 1. 1."), and 

 30. These four specimens present a puzzling combination of differ- 

 ences that with available material may not be treated satisfactorily. 

 The two females from Formosa and Paraguay, with a culmen 

 measurement of 20 and 21.5 mm., respectively, and a wing 52.5 mm. 

 long, agree fairly well with birds from Buenos Aires and offer noth- 

 ing M orthy of comment. A male taken on the Cerro Lorito on the 

 eastern bank of the Paraguay River opposite Puerto Pinasco has 

 the culmen 20.2 mm. and the wing 50 mm. It differs from any others 

 in the small series examined in having the entire maxilla dull black, 

 as well as the distal half of the mandible. In skinning this bird 

 I marked it as sexually fully adult, but it may be that the black bill 

 is still an indication of an immature condition. The last specimen, 

 a fully adult male, from the Chaco at Kilometer 80, with the culmeji 

 18.6 mm. and the wing 51.4 mm., in its small bill suggests the form 

 named mcLxiuelli by Hartert ^^ from the plains near Reyes on the Rio 

 Beni in northern Bolivia. Hartert records that specimens from 

 Matto Grosso seem intermediate between his form and the typical 



^ Hylocharis ruficolUs maxwelli Hartert, Nov. Zool., vol. 5, December, 1898, p. 519. 



