454 
LAME LLIROSTRAL SWIMMERS — ANSERES, 
The eggs of this species, in shape and general appearance, are undistinguishable 
from those of the Snow Goose. They are of a uniform dull-white color, and measure 
about 2.80 by 2.00 inches. 
Genus BERNICLA, Stephens. 
Bernicla, Stephens, Gen. Zool. XII. ii. 1824, 45 (type, Anas bernicla, Linn.). 
Leucopareia, Reich. Syst. Av. 1853, pi. ix. (type, Anser leucopsis, Bechst. ). 
Leucoblcpharon, Baird, B. N. Am. 1858, 763 (type, Anas canadensis, Linn.). 
With much the same form throughout as the species of Anser, those belonging to the genus 
Bernicla are distinguished by the darker plumage, with the head and neck chiefly black, and 
the bill and feet entirely deep black, at all ages. All the known species of Bernicla (as properly 
restricted) occur in North America, and may be defined as follows : — 
B. canadensis. 
A. Head and neck black, with a somewhat triangular patch of white on each cheek, usually con- 
fluent underneath the head, but sometimes separated by a black stripe or “isthmus” 
along the throat ; in some specimens a white collar around the lower neck. 
1. B. canadensis. Tail-feathers 14 to 20 inches ; wing, 13.60-21.00 ; culmen, .95-2.70 ; tar- 
sus, 2.10-3.70 ; middle toe, 1.80-3.40. Tail, rump, and primaries brownish black ; upper 
tail-coverts, crissum, and anal region white ; rest of the plumage grayish brown, lighter 
below, the feathers tipped with paler Hab. Whole of North America, south to Mexico. 
B. Head, neck, and jugulum black, the middle of the neck with a white patch on each side, or a 
wide collar of the same, interrupted behind. 
