230 Mr. J. G. Kerr on the Birds 



patch on the wing-coverts, apparently belonging to this 

 species, but it was unfortunately lost and I am unable now 

 to identify it with certainty. 



72. BOLBOKHYNCHUS MONACHUS (Bodd.). 



W., Oct. 31. 



73. Chrysotis estiva (Linn.). 



Numerous, S. Pedro, Sept. 25. Villa Concepcion. W. ; 

 common. 



74. PlONUS MAXIMILIANI (Kuhl). 



Near W., Feb. 23. 



Fani. XXI. B u b o n i d ^e. 



75. Speotyto cunicularia (MoL). 



I obtained a specimen at Waikthlatingmayalwa, the only 

 one I have ever seen so far north on the Chaco side of the 

 River Paraguay, though this species is quite common on the 

 eastern or Paraguayan side. 



76. Bubo virginianus (Gm.). 



W., Nov. 13. Occasional. Favourite food grasshoppers. 



Fam. XXII. FALcoNiDiE. 



77. Geranoabtus melanoleucus (Vieili.). 

 W., Jan. 1897. Occasionally seen soaring. 



78. Busarellus nigricollis (Lath.). 



Villa Concepcion, on Riacho Negro, Oct. 9, 1896. 



79. POLYBORUS tharus (Mol.). 



Villa Concepcion ; Caraya Vuelta, Oct. 23. W. Very 

 common. 



Fam. XXIII. Cathartid^e. 



80. Cathartes aura (Linn.). 

 Villa Concepcion. 



W. Less common than C. atratus and much more solitary 

 in habits. Large numbers seen on Feb. 28th. 



