BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 389 



in Gacicus as it was antedated by Tanagra alMrostris Linnaeus, 

 1764, a s3'nonym of Gacicus cela (Linnaeus), 1758. 



Vieillot's description of this small cacique was based on Azara 

 who gave no locality in connection with his notes on the yaqyu negro 

 y amarillo. The type-locality may be assumed to be Paraguay. 



The small, yellow-rumped cacique was common in the Chaco, but 

 was not recorded elsewhere. It was seen frequently at Resistencia, 

 Chaco, from July 8 to 10 (adult female, taken July 8), and at Las 

 Palmas, July 13 to 31. Near the Riacho Pilaga, Formosa, it was 

 found from August 7 to 18, and was seen near Formosa, Formosa, 

 August 23. In the vicinity of Puerto Pinasco it was noted from 

 September 1 to 30, from the Rio Paraguay, west for 200 kilometers. 



This cacique frequented forest trees in much the same manner 

 as orioles, though occasionally it came into bushes growing among 

 saw grass at the borders of savannas. Though oriolelike in form 

 and color in habits these birds differed, as, in addition to searching 

 the smaller branches, they crept about on the larger limbs or ex- 

 amined dead stubs by pushing and prying in crevices or bark with 

 the pointed mandibles separated at the tip. This was done force- 

 fully while the birds clung with their feet or braced with their tails. 

 On September 9 they were in pairs but were not breeding, and nest- 

 ing was not noted until September 30, when new nests under con- 

 struction were found. These were woven of a black rootlet and 

 hung as pendant bags from the tips of slender limbs. Some were 

 2 or 3 feet long, with a globular bag at the end to contain the nest 

 proper. 



The song was a sweet, broken warble and the note a mewing call 

 that may be represented as char. They were known commonly as 

 pajaro sergente from the yellow shoulder epaulettes, while the Toba 

 Indians designated them as ve da Ua koh. 



A female, shot July 8, had the bill sky gray ; iris pale ochraceous 

 salmon; tarsus and toes blackish brown. There was variation, 

 among them as to color of bill, from light to dark. One taken has 

 the crown and nape mottled with yellow. 



ARCHIPLANUS SOLITARIUS (Vieillot) 



Cassicus solitarius Vieillot, Nouv. Diet. Hist. Nat., vol. 5, 1816, p. 364. 



(Paraguay.) 



Hellmayr *^ has considered Cassicus nigerHmus of Spix ®* distinct 



from Cassicus solitarius Vieillot, but reference to Azara's original 



description of the yapu negro ^^ indicates that the two are identical. 



Azara remarks of the bill "' del color y materia que en el precedente." 



83 Abh. Kon. Bayerischen Akad. Wiss., Kl. 2, vol. 23, Abt. 3, May 20, 1906, p. 613. 

 8*Av. Spec. Nov. Brasiliam, vol. 7, 1824, p. 66, pi. 63, flg. 1. (Banks of the 

 Amazon.) 



s^Apunt. Hist. Nat. Pax. Paraguay, vol. 1, 1802, pp. 268-269. 

 54207—26 26 



