WHITE-TAILED HAWK. 23i 



celata, were shown to us, the error was immediately perceived. We 

 therefore hasten to correct this mistake, which would be otherwise of 

 more consequence, inasmuch as no one else could for a long time detect 

 it. This species resembles, it is true, *S'. celata (whose range must 

 remain limited to the Rocky Mountains), and perhaps still more, *S'. ruhri- 

 capilla, Wilson, but it is not of the same subgenus, Dacnis, and it may 

 readily be known by the white spots of the tail-feathers. 



When the genus Sylvia, containing upwards of two hundred and fifty 

 species, shall have been properly studied, it will be found practicable to 

 divide it into several more sections, subgenera, and even perhaps genera. 

 This bird, along with many other North American species, will consti- 

 tute a highly natural group, very distinct from the true Sylvia, of which 

 S. atricapilla may be considered as the type. We presume that it is 

 the group we have in view, to which Mr. Swainson has given the name 

 of Syluicola, in his Synopsis of Mexican Birds. Our species is errone- 

 ously placed by BuiTon among his Demi-fins, corresponding to our Dac- 

 nis, and Wilson's Worm-eate7-s. 



FALCO DISPAR. 



WHITE-TAILED HAWK. 



[Plate XI. Fig. 1.] 



Falco dispar, Temm. et Laug. PI. col. 319, young Female. Nob. App. 'to Synopsis 

 of N. A. Birds in Ann. Lye, New York, p. iZo.—Mllvus {now Elanoides) leucurus, 

 ViEiLL. {Alcon bianco^ d'Azara) Nuuv. Diet. d'Hist. Nat. xx., p. 556. — Falco 

 melanoptertis, Nob. Jour. Ac. Ph. v. p. 28. Id. Cat. Birds U. S. Sp. 16, in Conir. 

 Mad. Lye. i.. p. 11. Id. Synopsis of N. A. Birds, Sp. IT), in Ann. Lye. N. Y. — 

 Le Faueon blanc, Sonnini's d'Azara, iii., p. 96, Sp. 3G. 



This beautiful Hawk, which we recently discovered to be an inhabit- 

 ant of North America, is so strikingly similar to the Black-winged 

 Hawk [Falco melanopterus*) of the old continent, that we have hitherto 



* Falco melaiiopterus, Daud. Orn. 2, p. 152, Sp. 124. Lath. Ind. Suppl. p. vi., 

 Sp. 16. — Falco sonninensis, Lath. Ind. Suppl. p. xii., Sp. 38. — Elanus coesivs, 

 Savigny, Oi.«. d'Egyp. p. 98, pi. ii., f. 2. Yicill. Nouv. Diet, d'llist. Nat. viii., p. 

 240 (now Elanoides). — Elanus melanopierus, Leach Zool. Misc. iii., p. 4, pi. 122. 

 Vigors Descr. Austral. Birds in Tr. Lis. See. xv., p. 185. — Le Blac, Le Vaillant, 

 Oia. d'Afr. i., p. 147, pi. 36, Male, 37, young Male. — Black-winged Falcon, Lath. 

 Syn. Supfil. J I., p. 28, Sp. 23. — Sonnini's Falcon, Lath. Syn. Suppl. ii., p. 52, 

 Sp. 59. 



The inspection of original drawings, in a collection that Mr. Gray, of the British 

 Museum, was kind enough to show me lately in London, has enabled me to add to 



