326 STERCOKARIID^. 



whitish ; abdomen umber ; breast dull white ; flaoks and under 

 wing-coverts umber : bill horn-brown ; tarsi and toes reddish black. 

 Total length 21 inches, culmen 1-7, wing 14-25, tail about 5-25 

 (without the central rectrices, which sometimes project 4 inches), 

 tarsus 2-1, middle toe with claw 2. 



The sexes appear to be alike externally. 



In less mature birds the dark pectoral band is more extensive, 

 while the underparts, especially the flanks, are somewhat striated ; 

 the yellow on the neck is less pronounced. 



Adult in ivinter. Similar, but for some years after the attainment 

 of adult — though not mature — plumage there is a tendency, after 

 the autumnal moult, to show striated feathers on the flanks, upper 

 and under tail-coverts. 



Immature. Like the above, but with less yellow on the neck ; 

 the underparts more barred, but the upper and under tail-coverts 

 barred with black and white, and the under wing similarly mottled ; 

 central rectrices seldom projecting more than 2 in., and not twisted 

 terminally. 



Melanotic individuals — considered to be adults from the fact that 

 they show more or less yellow on the neck^ — sometimes occur, but 

 I do not think that any of these are really mature birds. One of 

 these originally dark individuals was kept alive by the late Mr. 

 Booth for some years, during which time its underparts became 

 gradually white. 



Birds of all ages occasionally exhibit spots of white on the carpal 

 joints. 



Yoimr/. Head and neck varying from clove-brown to sooty brown ; 

 feathers of the mantle dark brown, tipped with rufous in varying 

 degrees ; tail-coverts barred with black and rufous buff ; under 

 surface varying, from numerous bold striations of brown and rufous 

 to an ashy brown with faint striations, and again to an almost 

 uniform dull brown : bill brown with a greenish tinge ; tarsus often 

 blue or grey in patches : bases of the toes yellowish. 



Nestlhuf. Pale sooty brown, with a tinge of rufous. 



JJab. Arctic regions north of 70°: chiefly on tundras during the 

 breeding-season ; in winter southward, as far as Cape York in 

 Australia, Walvisch Bay in S. Africa, and Callao Bay in Peru. 

 Mr. L. Kumlien's statement that this species nests "in large 

 numbers on an inaccessible cliff " on Disco Island may be correct, 

 but it is opposed to the experience of every other observer. 



a. Juv. st. Hm'st Castle, Hants. R. B. Sharpe, Esq, 



[P.]. 



b. 2 juv. sk. Near Beccles, Suffolk, Oct. H. Saunders Coll. 



(W. M. Croufoot). 



c. $ juv. sk. yarraouth, Norfolk, Nov. {J. H. Saunders Coll. 



E. Harting). 



d. Ad.; e,f. Flamborough, Yorks (/. H. Hume Coll. 

 Juv. sk. Gjimey). 



g. $ inmi. sk. Scarborough, Oct. H. Saunders Coll. 



h. Juv. sk. North Britain. Old Coll. 



