BEAN-GEESE OF ASIA. 559 



Key to Bean-Geese (Melauonyx). 



I. Secondary coverts lavender-grey ; exposed culmen 

 plainly less than 1*95 in. long ; maximum depth of 

 lower mandible in closed bill 0-20—0-22 in., depth 

 of the whole bill at the forehead feathering about 1 

 in. ; legs and pale parts of bill pinkish-fleshy ; (wing 



15-7 — 17-5 in. long) brachyrhynchus BailL 



II. Secondary coverts dark greyish brown ; exposed 

 culmen plainly more than 1*95 in. long ; depth of 

 lower mandible in adult birds 0-23 in. and more ; 

 depth of bill l'l in. and more. 



A. Length of nail of upper mandible as seen from 

 above included in total length of exposed culmen 

 from 4 to about 4 J times -, depth of bill at the 

 limit of forehead feathering generally less or else 

 equal to half of length of exposed culmen ; 

 depth of lower mandible included in the length of 

 exposed culmen about 10 to 7 A times, rarely 7j 

 and quite exceptionally about 7 times ; number of 

 " teeth " on every side of upper mandible 25 — 30, 

 rarely 24 or 23 ; 



a. Depth of lower mandible 0-23 — 0-25 in. in 

 adults, 0-22 in. in young ones ; pale parts of 

 bill and legs flesh-coloured or rosy- pink ; 

 culmen about 2-16— 2-72 in. long ; (wing 



16-2—19-0 in. long) neglectus Sushkin. 



b. lower mandible 0'27 in. and more deep in 

 adults, not less than 0-23 in. in young ones ; 

 legs and pale parts of bill yellow or orange- 

 yellow ; 



a 1 , bill with yellow more or less prevailing 



over black in quite adulc birds or — in 



young and some old ones — at any rate 



yellow colouring stretches back on sides 



of bill some way under the nostrils ; 



depth of lower mandible 0'27 — 0-32 in., 



in young ones sometimes down to 0-23 in., 



in some big-billed old ones up to 0-36 



in. ; depth of bill 1*1 — 1-32 in. ; exposed 



culmen 2-42 — 2*83 in. ; along the base of 



upper mandible ordinarily (not always) 



a more or less distinct band of white 



feathers ; (wing 16-10 — 19-60 in. long) ... ar vensis Brhm. 

 6 1 . bill with black greatly prevailing even 



