THE SURF-SCOTER. 379 



difficult to estimate, whilst white wing-bar, which would at once 

 denote Velvet -Scoter, is not always visible in that bird. Under 

 such circumstances it would be no easy matter, even for one 

 familiar with these three species, to identify females at distance. 

 Chief cause of confusion with Scaup is explained under that species. 

 Keeps well away from shore and feeds both by day and night, 

 usually in 3-5 fathoms. In flocks of 20-40 individuals, but some- 

 times in many hundreds. (C. E. Alford.) 



Breeding-habits. — Little recorded. Nest. — Of dead vegetation, 

 lined dry grass and down in tussock on marsh, or on small island. 

 Eggs. — Usually 5 to 7, occasionally 8, variously described as creamy 

 and greenish-buff. Material scanty: one set averages 64.4x43.9 

 mm. Others are smaller, averaging (5) 58.7x41.1. Breeding- 

 season. — June. Incubation. — Apparently by female. Period un- 

 known. Single brooded. 



Food. — Chiefly marine mollusca especially mussels, but also razor- 

 shells (Solen), scallops (Pecten), sea-clams (Spisula), Nucula, etc. 

 Fish also said to be taken. 



Distribution. — British Isles. — Rare vagrant. Most frequent 

 Orkneys, where occasional examples, usually young, not infre- 

 quently seen and six recorded obtained. Several recorded seen 

 elsewhere, including one Kent, Jan., 1914, and following obtained : 

 O. Hebrides (one), Firth of Forth (one or two), Cumberland (one), 

 Lanes, (one), Scilly Isles (two), Cornwall (two), Devon (three), 

 Dorset (two). Six Ireland. 



Distribution. — Abroad. — Breeds in northern North America ; 

 non-breeding birds in summer on coast of Lower California, in 

 Greenland and on northern coasts of United States ; in winter 

 south to Lower California, Carolina, Florida. Casual in Bermudas 

 and Jamaica. Also (apparently breeding) on shores of Bering Sea, 

 and (according to Palmen) in extreme north-east of Siberia. A 

 number of occurrences on record from Fseroes, Lapland, Finland, 

 Scandinavia, Heligoland, Belgium, France. 



Genus MERGUS (L.) 



Mergtjs Linnaeus, Syst. Nat., ed. x, i, p. 129 (1758 — Type by subse- 

 quent designation, Gray, 1840, M. merganser). 



Differ from Ducks, Geese, and Swans by the narrow, slenderer 

 bill, in which the upper mandible does not overlap the lower. 

 There are no lamellae, but on the edges of both mandibles are saw- 

 like sharp teeth, directed slightly backwards. Nail large, occupying 

 whole tip, sharply decurved. Nostrils large and open slightly 

 beyond middle of mandible. Feet large, hind-toe broadly lobed, outer 

 toe weaker than inner. Both sexes with more or less elongated 

 head- or neck-feathers, forming more or less crests. Tail rounded 

 to almost cuneiform. Rectrices 16-18. Sexes different. 7 species, 



