70 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



hallux decidedly less than twice as long as that of outer toe) their 

 under surface smooth and rounded; a very slight web between basal 

 phalanges of outer and middle toes.^^ 



Plumage and coloration. — Plumage soft and blended, but feathers 

 of "mantle" distinctly outlined. Adults with underparts wholly 

 immaculate white, the under wing coverts, however, sometimes with 

 a patch of black; upperparts bluish gray, paler on head and tail, the 

 lesser wing coverts black. Young similar to adults but more or less 

 tinged or suffused with rusty, the tail v/ith a more or less distinct 

 terminal band of dusky. 



Range. — Occurs throughout most of the world from southern United 

 States, southern Europe and Asia south of the Himalayas, to all South 

 America, Africa, and Australia. Four species with several races, 

 only one of which occm-s in our limits. 



KEY TO THE SPECIES AND SUBSPECIES OF ELANUS " 



a. Axillars and a broad band across the under wing coverts black. 



E. scriptus ^> (extralimital) 



aa. Axillars white. 



b. Under wing coverts pure white with no black patch. 



E. caeruleus ^^ (extralimital) 

 hh. Under wing coverts white with a distinct patch of black near outer margin 

 of wing. 

 c. Greater under wing coverts, other than the black ones, dark ashy gray 



like under surface of remiges E. notatus « (extralimital) 



cc. Greater under wing coverts, other than the black ones, whitish tinged 

 with pale gull gray, distinctly lighter than under surface of remiges. 



d. Tail under 175 mm E. leucurus leucurus " (extralimital) 



(Id. Tail usually 175 mm. or longer (southern United States to Guatemala). 



E. leucurus niajusculus (p. 71) 



»» Pterylographical characters, according to Nitzsch (Pterylographia) are as 

 follows: "Remiges 25. Gular portion of the inferior tract very narrow, its inner 

 branch remarkably long. Outer branch of the pectoral stem connected for three- 

 fourths its length with the main stem, and then separated very perceptibly from 

 it. Dorsal portion of the spinal tract not reaching the fork of the scapular por- 

 tion, though two rows of single feathers which run parallel to it attain the fork. 

 Immediately outside these rows, commence two elliptical (inguinal) powder-down 

 tracts, pointed behind; these reach the lumbar tracts, which consist of only one 

 row of small feathers." 



Elanus is said to have one pair of inguinal powder-down patches. 



4" This key is based on adults only in the absence of adequate young material, 

 but from what I have seen it probably will work for young birds as well. 



" Elanus scriptus Gould, Proc. Zool. Soc. London, 1842, 80 (s. Australia). 



<2 Elanus caeruleus Desfontaines, Hist. (Mem.) Acad. Paris, 1787 (1789), 

 503, pi. 15 (Algiers). 



« Elanus notatus Gould, Syn. Birds Australia, pt. 4, 1838, app., i (New South 

 Wales). 



"Elanus leucurus leucurus {YiQiWoi) .^ Milv us leucurus Vieillot, Nouv. Diet. 

 Hist. Nat., XX, 1818, 5G3 (wrongly printed as 55G) (Paraguay). 



