1919-] Ecuador, Peru, Bolivia, and Argentina. 49 



some being much paler than others. I notice, too, that 

 Nos. 5216 and 5218 are somewhat darker thau those from 

 Cordoba. 



The immature female of P. r. ritijrhynchus is earth- 

 brown in its first plumage^ with a dull white throat. This 

 specimen was collected by C. H. B. Grant at Cape San 

 Antonio, Prov. Buenos Aires, on 21 December,1908: another 

 young bird, which is a male, was collected on the 28th of 

 the same month and has still got the dull white throat, but 

 is darker on the breast, abdomen, and flanks ; while a third 

 young bird collected at Ajo on 27 January, 1909, though 

 larger in size, differs but very little from the young female 

 mentioned above. A young female obtained on 4 February 

 at Los Ynglases has lost the white on the throat, which is 

 replaced by grey, and the breast and abdomen are becoming 

 slate- blue; yet another young male collected at the same 

 place on 10 February is still in the earth-brown plumage, 

 although it is larger in size. 



The young of P. r. sanguinolentus appears, from a specimen 

 collected at the Rio Cauta on"8 March, 1891, to pass through 

 a much darker phase of plumage, being coffee-brown in this 

 particular bird. 



After examining the series of Pardirallus rityrhynchus and 

 P. sanguinolentus in the British Museum, I have come to 

 the conclusion that the difference between the two can 

 only be regarded as snbspecific. P. rityrhynchus was 

 described by Vieillot from Paraguay, and ranges from there 

 to southern Brazil, Uruguay, and Argentina, and is not, 

 so far as I can gather, found on the western side of the 

 Andes ; wdiile P. sanguinolentus, which was described by 

 Swainson from Chile, does not occur on the eastern side of 

 the Andes. The character given for the separation of these 

 two species — namely, the greater amount of black on the 

 upper parts in P. rityrhynchus — is a variable one, and in 

 consequence of this the eastern bird has been said to occur 

 in western Peru, from the fact that the individuals from 

 north-western Peru show an increased amount of black on the 

 upper surface, compared with those of P. sanguinolentus from 



SEK. XI. VOL. I. B 



