18 COLLETT AND NANSEN. ACCOUNT OF THE BIRDS, [norw. pol. exp. 



have narrow, faint, and indistinctly defined, brownish black borders. Some 

 specimens, moreover, have traces of a brownish Idack shading ak>ng the sides 

 of the abdomen. 



The feathers of the lower part of the back are white, with broad, brownish 

 black borders, of which the external margin shows a tinge of pinkish grey. 

 The rump and the upper tail-coverts are white, some feathers, however, having 

 very faint indications of a dark border at the tip. 



The outer half of the shoulder-feathers and the upper wing-coverts is 

 broAvnish black, with narrow blackish grey borders ; the upper row of the 

 secondary wing-coverts (overlying the secondaries and tertiaries), however, 

 are already white in most of the specimens; while in two or three of them 

 they are dark like the rest of the coverts. 



Of the wing-feathers, all the primaries have black tips (about 20 mm. 

 broad); in the 1st, 2nd and 3rd, the outer web, shaft and adjoining portion 

 of the inner web is quite black, the rest of the inner web white. In the 

 4th and 5th, the white extends also to part of the outer web. The fea- 

 thers from the 6th to the 10th are chiefly white (above the black tip). In 

 most of the specimens, the black is sharply defined against the white; in a 

 few (possibly the youngest), the line of demarcation is less distinct, and the 

 colours less pure. 



The secondaries are white, the innermost, however, with increasingly 

 dark outer web. The tertiaries, which, when at rest, lie along the back, are 

 chiefly brownish black with narrow pinkish grey borders, like the rest of the 

 upper surface of the back. 



The primary coverts are brownish black, the secondary coverts white, 

 thus forming an oblong, white speculum upon the folded wing. 



The lower surface of the wing is white, though brownish black near the 

 outer margin: the shafts are white. 



Of the tail-feathers, only the two lateral ones, as a rule, are entirely white ; 

 Ihc rest have brownish black tips. In two or three of the specimens, the 

 3rd is also pure white, and in one of the eight, the 4th also. The brownish 

 black tip is broadest in the elongated 6lh (middle) tail-feather, where the 

 breadth is sometimes as much as 42 mm. (in most of them rather less, in 

 one only 26 mm.); in the long 6th rectrix, the dark terminal band runs in 



