THE SNOW-GEESE. 
225 
are now very properly dropped out of the list, viz., the Spur- 
winged Goose {Plectropterus gambensis), the Canada Goose 
(Bernicla canadensis), and the Bar-headed Goose indicus). 
All these birds are kept in confinement in this country, and 
there can scarcely be a doubt that the specimens which have 
been shot were simply escaped birds. 
THE SNOW-GEESE. GENUS CHEN. 
Chen, Boie, Isis, 1829, p. 563. 
Type, C. hyperboreus (Pall.). 
The genera of the Geese are separated by Count Salvadori 
according to the character of the serrations on the cutting-edge 
of the upper mandible, and the outline of this tomium, or 
cutting-edge, 'lluis the genera Chen and Anser have the latter 
decidedly sinuated, or concave, with the serrations visible from 
the outside for the greater part of its length. The species of 
the genus Chen are remarkable for a very stout bill, and for 
their snow-white or bluish colour, with black wings. The genus 
is arctic in its habitat. 
I. THE SNOW-GOOSE. CHEN HYPERBOREUS. 
Anser hyperboreus, Pall. Spiz. Zool. vi. p. 25 (1767); Seeb. Br. 
B. iii. p. 490 (1885). 
Anser alhatus, Cass. ; Saunders, P. Z. S. 1871, p. 519. 
Chenalbatus (Cass.), Dresser, B. Eur. vi. p. 409, pi. 417, fig. 2 
(1873); B. O. U. List Br. B. p. 117 (1883). 
Chen hyperboreus, Saunders, ed. Yarn Br. B. iv. p. 275 (1885); 
id. Man. Br. B. 393 (1889); Lilford, Col. Fig. Br. B. part 
xxvi. (1893). 
Adult Male.— General colour above and below snowy-white, 
the bird being everywhere pure white except on the wings ; 
primary-coverts ashy-grey ; primaries black, slightly washed 
with ashy at the base; “bill purplish-red, the nail whitish, and 
the intertomial space black; feet purple or orange-red, the 
soles dingy-yellow ; iris dark brown, eyelids whitish ” {R. 
Ridgway). Total length, 26-0 inches; culmen, 2-1 ; wing, 
i6-6 ; tail, 5 '5 ; tarsus, 2-8. 
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