454 



LAMELLIROSTRAL 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. 



Bemiela, Stephens, Gen. Zool. XII. ii. 1824, 45 (type, A)ias hernida, Linn.). 

 Leucopareia, Reich. Syst. Av. 1853, pi. ix. (type, Anser leucopsis, Bechst. ). 

 Leiicoblepharm, Baiud, B. N. Am. 1858, 7G3 (type, Anas canadensis, Linn.). 



With much the same form throughout as the species of A7iser, 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 : — 





-^ * ^i f 



B. canadensis. 



A. Head and neck black, with a somewhat triangular patch of Avhite 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, tlie fi'atlu is tipjied with paler Hah. AVhole of North America, south to Mexico. 



B. Head, neck, and jiiniilum black, the middle of the neck with a white patch on each side, or a 



wide coll.ir (if llie same, iiitcvrnpted ln'biiid. 



