436 LAMELLIROSTRAL SWIMMERS — ANSERES. 



it by Mr. D. G. Elliot, since the difference in the character of the bill from that of the typical 

 species of the genus is hardly of generic value. The species may be distinguished as follows : — 



Synopsis of Species. 



A. Plumage never chiefly white ; the adult mainly grayish brown, with bluish-gray rump and 



win"-coverts, the head and part of the neck white. Young almost wholly grayish brown, 

 including head and neck. 



1. C. ccerulesceus. liill very robust, the posterior lateral outline of the maxilla decidedly 



concave ; commissure widely gaping, and lower outline of the mandible decidedly convex. 

 Win'% about 15.00-17.00 inches; culmen, 2.10-2.30 ; tarsus, 3.00-3.30 ; middle toe, 2.15 

 -2.50. Hub. Interior of North America ; Mississippi Valley, chiefly in winter. 



B. Plumage of the adult pure white, the primaries black, more grayish toward the base ; young 



grayish white, the centres of the feathers darker gray. 



2. C. hyperboreus. I'ill robust, and shaped like that of G. ccerulescens. Wing, 15.00-18.50 



inches ; culmen, 1.95-2.80 ; depth of maxilla at base, 1.15-1.50 ; tarsus, 2.80-3.50 ; 

 middle toe, 2.10-2.90. Hab. The whole of North America. 



3. C. Rossi. Bill small, the posterior lateral outline of tlie maxilla almost perfectly straight, 



the tomia closely approximated, and the lower outline of the mandible scarcely convex ; 

 in older specimens tlie base of the maxilla corrugated or warty. Wing, 13.75-15.50 

 inches ; culmen, 1.50-1.70 ; depth of maxilla at base, .85-.95 ; tarsus, 2.30-3.00 ; middle 

 toe, 1.80-2.05. Hab. Northwestern North America. 



Chen caerulescens. 



THE BLUE- WINGED GOOSE. 



Anas ccerulescens, Linn. S. N. ed. 10, I. 1758, 124 ; ed. 12, I. 1766, 198. — Gmel. S. N. I. 1788, 



513. — Lath. Ind. Orn. II. 1790, 836. 

 Anser ccerulescens, Vieill. Enc. Meth. I. 1823, 115. — Bahid, Cat. N. Am. B. 18.^9, no. 564.— 



CouES, Key, 1872, 282 ; Check List, 1873, no. 479 ; Birds N. W. 1874, 553. 

 Chen ccerulescens, Ridgw. Proc. U. S. Nat. Mus. Vol. 3, 1880, 202 ; Norn. N. Am. B. 1881, no. 



590. — CouES, Check List, 2d ed. 1882, no. 694. 

 Anser hypcrhorcus (suppos(^d young), Stephens, Shaw's Gen. Zool. XII. ii. 1824, 33. — Baird, 



B. N. Am. 1858, 760. 



Hab. North America in general, but chiefly the interior. 



Sp. Char. Adult : Head and upper half of the neck white, or mostly white, the former fre- 

 quently washed with orange-rufous anteriorly ; lower neck and body grayish brown, the feathers 

 bordered terminally with ])aler, these pale edgings, however, nearly obsolete on the neck, where 

 the tint is darker, inclining to plumbeous-umber, which joins irregularly against the white above 

 it. Rump and wings plain pearl-gray or bluish cinereous (the former sometimes wlute), in strik- 

 ing contrast to the deep grayish brown of the scapulars, sides, etc. ; that of the rump fading into 

 white on the upper tail-coverts, and that of the greater coverts edged externally with the same. 

 Primaries Idack, fading basally into hoarj'- gray ; secondaries deep black, narrowly skirted with 

 white ; tail deep cinereous, the feathers distinctly bordered with white. Bill reddish, the com- 

 missural space black ; feet reddish. Young: Very siniilar. but tlie chin, only, white, the rest of 

 the head and neck being uniform plumbeous-umber or brownish plumbeous, like the breast, only 

 darker in shade ; body more cinereous than in the adult, the pale tips to the nearly truncated 

 contour-feathers being obsolete. Rump, wings, and tail as in the adult. Bill and feet blackish. 

 Downy young, not seen. 



Total length, about 30.00 inches ; wing, 15.00-17.00 ; culmen, 2.10-2.30 ; tarsus, 3.00-3.30 ; 

 middle toe, 2.15-2.50. 



The cliief variati(jn in tlie plumage of adults of tliis .species consists in the extent and continuity 

 of the white of the neck. This is usually more or less broken, the dusky of the lower portion 

 running upwards in irregular spots or projections ; it extends highest on the nape, where it some- 



