-268 Sharpe oti the Genus Prague. [October 



which formed part of the studies of Professor Baird in his 

 celebrated 'Review,' I have the pleasure to forward to 'The Auk' 

 my first contribution (out of many, let us hope) to that Journal, 

 on the subject of these interesting specimens. 



I do not propose to treat of P. dominicensts, P. chalybea^ or 

 P. tafera^ which are easily distinguished, but of the unicolorous 

 blue species, P. purpurea {P. subts^i auct. Amer.), P. furcata, 

 and P. concolor. I have found, as 1 believe, a new and easy 

 way of distinguishing these whole-colored species, one which, 

 at least, I have not seen mentioned in any work with which I 

 am acquainted, and this is, by the number and position of the 

 ^ilky-white tufts of feathers on the lower back and flanks. Of 

 these tufts, P. purpurea has two., one on the side of the lower 

 back, and a second one on the flanks. P. furcata has only a 

 single white tuft on the lower back, and P. concolor has none 

 at all. 



The geographical distribution of these three species is also 

 interesting, for we find that the Brazilian Purple Martin is true 

 P. purpurea^ and the adult male of Baii'd's Progne elegans is 

 only P. ptirpurea shot in its winter quarters, which, be it 

 noted, it shares with two other North American Swallows, 

 Petrochelidon pyrrJionota and Hiru?ido erythrogastra. The 

 female and young birds of P. elegans are of the same species as 

 P. furcata., as we have satisfied ourselves by an examination of 

 a large series in the British Museum, and in the collections of 

 Dr. Sclater and Messrs. Salvin and Godman. Female birds from 

 Mendoza are identical with the types of P. elegans from Para- 

 guay, and these two localities doubtless mark the horizontal 

 range of P. furcata., which De Philippi does not allow to be a 

 Chilian species. 



I propose to ornithologists to adopt the name of P. ftircata., 

 Baird, for the southern Purple Martins, as the Progne elegans 

 of the same author is now seen to be founded on examples of 

 two different species. In conclusion I wish to acknowledge the 

 obligation which I owe to Professor Baird and my friends at the 

 U. S. National Museum for the privilege of examining these 

 interesting types, although, thanks to the excellence of Professor 

 Baird's descriptions, I had come to the conclusion here recorded 

 without even seeing the specimens, the loan of which came 

 upon me as a most agreeable surprise. 



