58 THE TERNS 



dress. (PL 99.) Length 14-25 in. [361-94 mm.]. The forehead, crown, and nape 

 are black, the interscapulars, scapulars, and wings are of a dark pearl-grey, the 

 rump and tail feathers white, the latter tinged with grey along the outer webs, 

 darkest on the " streamers." The outermost primary has the outer web dark 

 slate colour, the inner with a band of dark grey along the shaft, the rest of 

 the web being white except towards the tip, which is dark ash-grey ; inner 

 primaries paler grey with white " wedges." The secondaries are tipped with 

 white. The throat is white, the rest of the under parts pale lavender-grey. 

 The beak is orange-red, dusky at the tip ; the legs and toes coral-red. After the 

 autumn moult the fore-part of the crown becomes largely intermixed with white, 

 and the under parts are almost pure white. In the juvenile plumage the pearl- 

 grey of the upper parts is darker than in the adult, and obscured by broad terminal 

 fringes of deep buff and subterminal bars of slaty black. The forehead and fore- 

 part of the crown are buff coloured, and the hind-crown and nape dull black ; 

 the lores are also black. The inner secondaries are tipped white, and have 

 subterminal loops of dark brown. Primaries much darker than in the adult, and 

 with subterminal bars of dull slate-black, and a strongly marked white line along 

 the free edge of the inner web. Tail much darker grey than adult. In some 

 individuals the mantle is marked with wavy lines of black and brown, and the 

 hindmost scapulars and inner secondaries have conspicuous loops of dull slate- 

 black alternating with loops of white. In such birds the white of the forehead 

 is thickly spotted with dark grey obscuring the white. The inner wing-coverts 

 are powdered with black and buff. In other individuals the black is conspicuous 

 by its absence and the pearl-grey clouded with brown, as also are the forehead 

 and fore-part of the crown, but the lores, hind-crown, and nape are dull black. 

 After the autumn moult the only sign of immaturity is a band of dark grey 

 across the upper wing-coverts. The young in down (protoptyle) are of a pale 

 smoke-grey, tinged with buff, except the cheeks, which are pure grey. This 

 ground-colour is relieved by black markings, which on the back may form two 

 indistinct longitudinal stripes. In some chicks the ground-colour of the upper 

 parts is much deeper. A live specimen noted at Romney was dusky buff with an 

 unusual number of black irregular markings (F. B. Kirkman). The same varia- 

 tion has been noted at Ravenglass (H. W. Robinson, British Birds, iii. 169). Both 

 at the latter colony (loc. cit,) and at Muskeget, off the New England coast, the 

 chicks have been noted to vary in the coloration of the legs, some having them 

 reddish, others flesh-coloured or yellowish (G. H. Mackay, Auk, xiii. 52). The 



