BRITISH BEAN-GEESE. 45 



two species, included in the total length of culmen three and a 

 half times ; colour black, with only an orange band between the 

 nail and nostrils in typical specimens, but the orange, as I have 

 remarked, is subject to variation in distribution in a more or less 

 degree, sometimes extending below the nostril, but this varies 

 according to age. 



Fig. 2, side view of same. — Culmen considerably curved, 

 lower mandible deep and swollen about the basal third ; average 

 number of laminae along each edge of upper mandible from 20 

 to 21 ; colour black, with orange band encircling bill in front of 

 nostrils ; nail and corresponding portion of under mandible 

 black. As a rule, no white feathers at the base of bill, excepting 

 in old birds, when a small frontal patch of greyish white may 

 occur. 



Fig. 3, Anser arvensis, $ . — Bill (upper view) : length of 

 culmen rather over %\ in. ; nail proportionately small and 

 rounded, included in the total length of culmen four and a half 

 times. Orange colour extending nearly over the whole of the 

 upper mandible, having only a black bar commencing in front of 

 the nostrils, and running along the culmen to the base, where it 

 becomes paler. 



Fig. 4, side view of same. — Straighter than that of segetum, 

 and the lower mandible less swollen ; average number of laminae 

 about 28 along each edge of the upper mandible ; a few at each 

 end are very small, and hidden from view by the overlapping edge 

 when seen from the side only. Upper mandible almost wholly 

 orange, excepting the black nail on bar and along the culmen, 

 and one or two irregular blackish streaks on the sides. Lower 

 mandible : end black, anterior two-fifths orange, remainder black ; 

 conspicuous band of white feathers extending along the whole 

 basal edge of upper mandible. 



