2158 The Zoologist — June, 1870. 



of the rami, there is a small pit or fossa between them, just at their 

 junction, which is unfeathered. Wings and tail of the usual length 

 and shape; the length of the latter contained about three and two- 

 thirds times in the length of the former from the carpal joint to the 

 end of the longest feather. Tarsus shorter than the middle loe 

 without its claw. 



Adult: Without a crest. A series of elongated very slender 

 filamentous white feathers from the eye backwards and downwards, 

 white. Entire upper parts, with chin, throat, breast, and flanks, 

 fuliginous or brownish-black, lighter or grayer below than above; 

 other under parts pure white, pretty trenchantly defined against the 

 darker colour of the breast. Bill orange or coral-red, becoming 

 enamel yellow at the tip, and along the cutting edges. Legs and 

 feet dull greenish, darker posteriorly (in the dried state). 



The above is the state of plumage of apparently most mature birds; 

 but is much more rarely met with than the succeeding:— Upper parts 

 as just described, but no whitish feathers below and behind eye. 

 Entire under parts white, marbled on the throat, breast and sides with 

 dusky or blackish ; this colour usually occupying chiefly or wholly 

 the tips of the feathers, whose bases are white. The mottling is 

 thickest on the breast, most sparse on the abdomen ; but it varies in 

 degree with almost every specimen. A state of plumage is described 

 as that of the young, in which the white occupies nearly the whole 

 under parts, and is scarcely mixed with dusky, even on the throat and 

 breast. This slage is not represented in American Museums. The 

 tendency of the mottling, as the bird grows older, seems to be to 

 increase on the throat, breast, perhaps on the sides and flanks, and to 

 disappear from the other under parts, leaving the latter pure white, in 

 marked contrast. The under wing-coverts are always dark ashy 

 brown ; the short tibial feathers the same. 



Length about 900; wing 5-40 to 575; tail I'SO to 160 ; tarsus 

 (average) I'OO; middle toe MO. Bill: chord of culmen '60, chord 

 of gonys just about the same; depth opposite posterior end of 

 nostrils -45; width at same point -30; rictus nearly or about TOO. 



This very curious species may be instantly recognized, in whatever 

 stale of plumage, by the remarkable configuration of the bill ; the 

 rictus being strongly curved upwards, the upper mandible oval, obtuse, 

 the lower falciform, acute. It is one of the longest and best known 

 of the North Pacific representatives of the family, and is apparently a 

 very common bird, though specimens do not occur in collections so 



