436 LAMELLIEOSTEAL SWIMMERS — ANSEEES. 



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

 species of the gemis is hardly of generic ^•alue. The species may ht distinguished as follows : — 



Synopsis of Species. 



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



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

 including head and neck. 



1. C. caerulescens. Bill very robu.st, the posterior lateral outline of the maxilla decidedly 



couca\ e : commissure widel}' gaping, and lower outline of the mandible decidedly convex. 

 Wing, about 1.5.00-17.00 inches; culmen, 2.10-2.30 ; tarsus, 3.00-3.30 ; middle toe, 2.15 

 -2.50. Hah. 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 \\liitc, the centres of the feathers darker gray. 



2. C. hyperboreus. Bill robust, and shaped like that of G. cccrulesccns. Wing, 15.00-18.50 



inches ; culmen, 1.93-2.80 ; depth of maxilla at base, 1.15-1.50 ; tarsus, 2.80-3.50 ; 

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



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



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

 in older specimens the 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 cmrulescens, Linn. S. N. ed. 10, I. 1758, 124 ; ed. 12, 1. 1706, 198. — Gmel. S. N. I. 1788, 



513. — Lath. Ind. Orn. II. 1790, 830. 

 Anser ccerulescens, Vieill. Euc. Meth. 1. 1823, 115. — B.\tRD, Cat. N. Am. B. 1859, no. 564. — 



COUES, Key, 1872, 282 ; Check Li.st, 1873, no. 479 ; Birds N. W. 1874, 553. 

 C'licn ccerulescens, Ridgw. Proc. U. S. Nat. Mus. Vol. 3, 1S80, 202 ; Nom. N. Am. B. 1881, no. 



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

 Anser hyperboreus (.supposed young), Stepuen.s, Shaw's Gen. Zool. XII. ii. 1824, 33.- — Baird, 



B. N. Am. 1858, 700. 



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



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

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

 bordered terminally with jxiler, these pale edgings, however, nearly obsolete on the neck, where 

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

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

 ing contrast to the deej) 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 black, fading basally into hoary gray ; secondaries deep black, narrowly skirted with 

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

 missural space black ; feet reddish. Youny : Very similar, Ijut the chin, oidy, white, the rest of 

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

 darker in shade ; boily 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. 

 Doiony yimng, 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 chief variation in the 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 ujiwards in iiivgular spots or projections ; it extends highest on the nape, wdiere it some- 



