leaving the chin and upper throat, breast, abdomen, and under tail-coverts white. One immature 

 specimen in the Museum, from Bahia, has a yellowish tinge on the abdomen. 



The ovate drops of dark brown colour on the breast are developed to a greater extent during 

 the breeding-season, if indeed they are not the principal evidences of nuptial plumage. They are 

 never seen in young birds, and there are many specimens in the British Museum which have no 

 trace whatever of these spots on the breast, being, moreover, almost entirely uniform hoary 

 white underneath, excepting for a brownish shade on the fore neck and chest. The irregularity 

 which characterizes the brown spots on the chest in these hoary specimens confirms our opinion 

 that they are only developed when the nesting-season approaches. 



At first we were inclined to think that the absence of these brown spots on the breast was only 

 noticeable in specimens from northern localities, and certainly in a series from some places, such 

 as Bahia, whence there are several specimens in the British Museum, not a single one has a trace 

 of spots on the breast, whereas every one from the neighbourhood of Buenos Ayres (where the 

 bird breeds) has these spots extremely well developed and the entire plumage very dark. All 

 these specimens, however, are adult, and it is much to be desired that the young from the nest 

 should be examined by a competent observer and the first plumage carefully described. 



Hub. The greater part of South America. 



The habits of this species, as detailed below, and the totally different style of plumage, 

 present such a variation from the purple appearance of the ordinary members of the 

 genus Progne, that there is a good deal to be said in favour of its separation under the 

 subgeneric heading of Plneoprogne. 



Our chief knowledge of the Tree-Martin is derived from observers in the Argentine 

 Republic, and excellent notes on the species will be found below. The late Mr. Henry 

 Durnford states that it arrives in the neighbourhood of Buenos Ayres in September, 

 nests, and leaves about the first week in April. Mr. Hudson has collected many speci- 

 mens near Conchitas, and Mr. E. W. White sent some from Oran in the Salta district, 

 Monte Grande, and Pacheco. Prof. Burmeister met with it in the eastern La Plata dis- 

 tricts, and states that it was not rare near Parana. In Uruguay, Mr. Barrows notices 

 its arrival about the same time as Progne purpurea, viz. about the middle of September. 

 The Smithsonian Institution possesses examples from the Bio Vermejo. 



It extends to Bolivia, where d'Orbigny met with it in the province of Chiquitos, 

 and a specimen obtained in that country by Mr. Bridges is in the British Museum. - In 

 Brazil, writes Prof. Burmeister, it is an inhabitant of the Campos districts in the interior, 

 but is nowhere very common. It does not live m the woods there, but frequents the 

 scattered bushes on the Campos, hunting for insects, nesting in old trees, and avoiding 

 the neighbourhood of man. The localities where Natterer observed the species were the 

 following : — Porte do Bio Araguay (October) ; Engenho do Cap. Ant. Correia (December) ; 

 Cuyaba (July, September) ; Caicara (January, October, and November) ; Maribatanas, 

 (April); Barra do Rio Negro (February). He states that it was common in Cuyaba, 

 living in the deserted nests of Purnarius rufus, and that it goes away at the beginning of 



