334 Mr. J. H. Gurney's Notes on 



somewhat darker than is usual in Australian specimens^ with 

 which, however, it appears to agree in all other respects. 



The two Australian Elani {E. axillaris and E. scriptus) 

 are both remarkable for the great paleness of the grey tints 

 of the upper surface ; and this circumstance appears to mc to 

 constitute the most marked and constant distinction between 

 E. axillaris and the American E. leucurus, which (as the 

 later-described species) should, I think, be considered a 

 a subspecies of E. axillaris. It ought, however, to be ob- 

 served that some slight individual variations in the tint of 

 grey on the back occur in both E. axillaris and E. leucurus, 

 sometimes producing a greater approximation between the 

 two in such examples than exists between the bulk of average 

 specimens of the two races. 



Messrs. Baird, Brewer, and Ridgway, in their ' History of 

 North- American Birds,' vol. iii. p. 196, devote an article to 

 the different " species and races " of the genus Elanus, in 

 which, under the head of "E. leucurus," the following dia- 

 gnosis is given : — 



^' Above deep bluish ash, with the inner webs of the secon- 

 daries appreciably paler, sometimes abruptly white ; wing 

 11-60-12-65, tail 6-80-7'80, culmen -GS-'SO, tarsus 1-20-1-50, 

 middle toe •9Ji-l'20. Hab. Tropical and Subtropical Ame- 

 rica. — Var. leucurus. Above, pale ash, with the inner webs 

 of the secondaries hardly, or not at all appreciably paler than 

 the outer; wing 11-00-12-50, tail 6-20-7-00, culmen ■7Q-'77, 

 tarsus 1-10-1 -66, middle toe 1-05-1-08. Hab. Western Aus- 

 tralia. — Var. axillaris .... Occasional specimens of E. leu- 

 curus occur, however, in which there is little difference in 

 tint between the two webs of the secondaries." 



Mr. Sharpe, in his " Key to the Species " of the genus 

 Elanus, gives a somewhat different diagnosis between E. ax- 

 illaris and E. leucurus, which I will also quote. 



''Black patch on under wing-coverts very large, tlie 



greater series dark ashy grey, like the wing-lining. . axillaris. 

 Black patch on under wing-coverts less, and confined to 

 a small patch on the outermost greater coverts, the 

 rest of the series white slightly tinged with grey . . leucurus. 



