THE SNOW-GEESE. 225 



are now very pro|)erly dropped out of the list, viz., the Spur- 

 winged Goose {Pledroptenis gambensis), the Canada Goose 

 {Bernicia canadensis), and the Bar-headed Goose (A. indicus). 

 All these birds are kept in conHnement in this country, and 

 there can scarcely be a doubt that the specimens which have 

 been shut were simply escaped birds. 



THE SNOW-GEESE. GENUS CHEN. 



Chen, Boie, Isis, 1829, p. 563. 



Type, C. hyperbo7'eus (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. Thus the genera Chen and Anscr\\d.-wQ 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 HYPEREOREUS. 



Anser Jiyperboreus, Pall. Spiz. Zool. vi. p. 25 (1767); Seeb. Br. 



B. iii. p. 490 (1885). 

 Anser albatus, Cass. ; Saunders, P. Z. S. 1871, p. 519. 

 Chen albatus (Cass.), Dresser, B. Eur. vi. p. 409, pi. 417, fig. 2 



(1873); B. O. U. List Br. B. p. 117 (1883). 

 Che7i hyperboreus, Saunders, ed. Yarr. Br. B. iv. p. 275 (1885); 



id. Man. Br. B. 393 (1889); Lilford, Col. Pig. 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. 



8 o 



