122 Mr. J. Graham Kerr on the Avifauna 



banks are higher and less exposed to inundation — the palmar 

 disappears and the dicotyledonous forests increase greatly in 

 luxuriance and extent. The borders of the Chaco both on 

 the west and east appear to possess a very much richer 

 fauna and flora than its interior. 



The list which follows may, I think, be taken as giving 

 a fairly good idea of the general facies of the avifauna of 

 the interior of the Chaco, but by no means of the richly 

 forest-clad regions upon its borders. 



In concluding these remarks, I must record my great 

 indebtedness to Mr. Sclater for his invaluable advice and 

 assistance. 



11. List of Birds collected upon the Lower Pilcomayo. 

 The numbers enclosed in parentheses refer to skins which 

 I have brought home, and of which I have been able to con- 

 firm the identification by comparison with marked specimens 

 in the British Museum. 



The following are the principal localities mentioned : — 

 " Estancia Gil," situated upon the left bank of the Pilco- 

 mayo, close to its mouth. 

 "Las Juntas;' lat. 2J.° 56' S., long. 58° 15' W. {Storm.) 

 '' Fortin Nueve," lat. 24° 53' S., long. 58° 30' W. {Paye.) 

 '' Fortin Donovan/' lat. 24° 52' S., long. 58° 40' W. {Paffe.) 

 ''Fortin Page," lat. 24° 47' S., long. 58° 45' W. {Page.) 

 These positions can only be regarded as approximate. 

 The nomenclature and arrangement are those of Sclater 

 and Hudson^s 'Argentine Ornithology,^ to which work a 

 reference is given after the name of every species that is 

 mentioned in it. 



1. TURDUS LEUCOMELAS. {Op. cit. i. p. 1.) 



(No. 116, ? .) Near Fortin Page. May 26th, 1890. 

 Observed only once. The specimen was feeding on low 

 open ground near the river in company with T. rujiventris. 



2. TuRDUS RUFIVENTRIS. {Op. Ctt . i. p. 3.) 



(No. 89, S ') ^ovt\\\ Donovan. May 3rd, 1890. 

 Abundant on the Pilcomayo, where it frequents the open 

 woods and brush. Its favourite feeding-grounds are the 



