THE COMMON EIDER. 361 



moulted. Only one examined. Second winter and summer. — Like 

 that of adult but white tips to secondaries and greater coverts 

 narrower. Moult as adult. Second eclipse not examined but in 

 third winter is not to be distinguished with certainty from adult. 



Measurements and structure. — <$ wing 280-298 mm., tail 84-95, 

 tarsus 45-52, bill from point of feathers on culmen 49-56, from 

 point of frontal angle 68-77 (12 measured). ? wing 266-295, bill 

 from point of feathers on culmen 44-56. Primaries : 1st narrow, 

 pointed and about two-thirds longest primary-covert, 3rd longest, 

 2nd 2-8 mm. shorter, 4th 8-11 shorter, 5th 20-26 shorter, 6th 35-42 

 shorter ; 2nd emarginated inner, 3rd outer webs. Innermost second- 

 aries falcate, moderately long, tapering to a point, longest shorter 

 than 6th or 7th primaries. Long lower scapulars stiff, tips of outer 

 webs emarginated in ad. $ and in some ad. ?, rest of scapulars softish 

 more or less pointed at tip, in eclipse square. Tail short, rounded 

 with 14 stiff, pointed feathers. Bill nearly as long as head, higher 

 than broad at base, depressed towards end where considerably 

 narrowed but rounded, nail large, elliptical, convex and moderately 

 decurved, with a thick grooved edge ; maxillary tomium regular 

 and nearly straight ; lamella? completely concealed. Feathers of 

 fore -head continued to a narrow point on culmen about half-way 

 between base of frontal angle and nostril separating the backward 

 processes or frontal angles of maxilla ; loral feathering extending 

 to about middle of nostril opening. 



Soft parts. — Bill (ad. $) basal part of upper mandible oil-green, 

 rest bluish-grey tinged green, nail greyish -yellow, nail and tip of 

 lower mandible pale greenish-grey, rest bluish-grey tinged green, 

 (ad. §) greenish -dusky, nail of upper mandible bluish-horn, that of 

 lower purplish ; legs and feet (ad. $) oil-green, membranes and soles 

 pale greenish -brown, claws pale brown, (ad. $) greenish -dusky, (juv. 

 <$) lead-grey ; iris rich brown. 



Characters and allied forms. — S. m. norvegica (Norway east to 

 Russian Lapland) has steeper and less sloping fore -head, in adult 

 male frontal angles usually narrower and more pointed, adult 

 females less brilliant in colour ; S. m. fceroeensis (Faeroes) is smaller 

 with much smaller bill ; S. m. borealis (Greenland (possibly Iceland), 

 Ellesmere-land, to north-west Hudson Bay and S. Ungava) has bill 

 in adult male smaller and in spring bright orange -yellow, sickle- 

 shaped innermost secondaries as a rule longer ; S. m. dresseri 

 (S. Ungava to south-east Maine and southern half Hudson Bay) has 

 frontal angles broader than in S. m. mollissima and green of head 

 usually extending below black almost to bill, an indistinct black 

 V on chin (but this also occurs sometimes in S. m. mollissima), 

 colour of bill as in S. m. borealis ; S. m. v-nigrum (N.E. Siberia, 

 Alaska) has always in adult male a large black V-shaped mark on 

 chin. S. m. mollissima is distinguished in all plumages from other 

 British ducks by its large size and characteristic frontal angles of 

 bill. For distinctions of S. spectabilis see under that species. 



