BLUE HAWK, OR HEN-HARRIER. 239 



■will find that the chief difiference between the sexes consists in the 

 female being green instead of blue, in her wanting the black streaks, 

 and in being tinged with yellow beneath. 



We have to regret our inability to add much to Wilson's short and 

 imperfect account of the species. It is by no means more common at 

 this time, than it was when he wrote ; which may account for the diffi- 

 culty of ascertaining the period of its migrations, and for the circum- 

 stance of our having never met with the nest, and our want of acquaint- 

 ance with its habits. We can only add to its history, that it is found in 

 the Trans-Mississippian territory ; for the Sylvia hifagciata of Say, ac- 

 curately described in Long's first expedition, is no other than the male. 

 We have examined the specimen shot at Engineer Cantonment. 



Although the- undisputed merit of first making known this species 

 belongs to Wilson, yet the scientific name that he applied to it cannot 

 be retained, inasmuch as it is preoccupied by the Blue-gray Warbler, a 

 Linnean species, which Wilson placed in Muscicapa, but which we con- 

 sider a Sylvia, notwithstanding that it does in some degree aberrate 

 from the typical species of that genus.* Under such circumstances, we 

 cannot hesitate in adopting the name substituted by Mr. Stephens, the 

 continuator of Shaw's compilation. 



FALCO CYANEUS. 



BLUE HAWK, or HEN-HARRIEK.f 



[Plate XII.] 



Falco cyaneus, Linn. Sijsi. i., p. 126, Sp. 10. Gmel. Sysi. i., p. 276, Sp. 10. Iter 

 Poseg. p. 27, adolescent Male. Lath. Ind. Orn. i., p. 39, Sp. 94. Montague, in 

 Trans. Lin. Soc. ix., p. 182. Meyer,- Tasch. Deutschl. Vog. i., p. 145. Temm. 

 Man. Orn. i., p. 72. Ranz. El. Zool. in., PI. 7, p. 137, Sp. 28. Brehm, Lehrb. 

 Eur. Vog. i., p. 59, Selby, III. Brit. Orn. i., p. 26, PI. 10, fig. 1, Male, fig, 2, 

 Female. Savi, Orn. Tosc. i., p. 63. Nob. Cat. and Sxjn. Birds U. S. Sp. 22. — 

 Falm pygargus, Linn. Byst. i., p. 126, Sp. 11. Gmel. Syst. i., p. 277, Sp. 11, 

 Female and young. — Falco Hudsonius, Linn. Syst. i., p. 128, Sp. 19. Gmel. 

 Syst. I., p. 277, Sp. 19, young American. — Falco bohemicus, Gmel. Syxt. i., p. 

 276, Sp. 107. Lath. Ind. p. 38, Sp. 93, adult Male. — Falco albicans, Gmel. Syst. 

 I., p. 276, Sp. 102. Lath. Ind. p. 38, Sp. 93, adult Male. — Falco griseus, Gmel. 

 Syst. I., p. 275, Sp. 100. Lath. Ind. p. 37, Sp. 86. Gerard. Tabl. Elem. p. 37, 

 adolescent Male. — Falco montanus, var. B. Gmel. Syst. i., p. 278, Sp. 106. 



* See my Observations on the Nomenclature of Wilson's Ornithology. 

 \ See Wilson's American Ornithology, Vol. i., p. 79, PI. 51, fig. 1, for the young 

 (under the name of Marsh-Hawk, Falco uliginosus). 



