OYSTEK-CATCHEK 251 



In many districts of the British Isles this is a common 

 breeding-species. Thus the numerous islands which stud 

 the Atlantic-facing coasts of Scotland and Ireland, are 

 annually tenanted by numbers. On the mainland, espe- 

 cially that of Scotland, the bird is also a common nesting- 

 species, but along the southern coasts it breeds much more 

 sparingly. 



Geographical distribution. Abroad, it breeds over a vast 

 area of Temperate and Northern Europe and Asia, includ- 

 ing large inland waters. In winter, great numbers push 

 southward, reaching Southern and Western Asia, and North 

 Africa. 



DESCRIPTIVE CHARACTERS. 



PLUMAGE. Adult male nuptial. Middle and lower back, 

 breast, abdomen, and a small spot under the eye, white ; 

 elongated patch on the wing, white ; rest of plumage, black. 



Adult female nuptial. Similar to male plumage. 



Adult winter, male and female. Similar to nuptial 

 plumage except that a portion of the throat is white and 

 there is a broad white crescent on the side of the neck. 



Immature, male and female. The feathers of the back 

 and wings are edged with brown ; middle of throat banded 

 with white. 



BEAK. Reddish, becoming lighter in shade towards 

 the tip ; compressed from side to side and blunted at the 

 extremity. 



FEET. Deep pink ; thick and fleshy. 



IRIDES. Crimson. 



AVERAGE MEASUREMENTS. 



TOTAL LENGTH 16'5 in. 



WING 9'75 ,, 



BEAK 2'5 



TARSOMETATARSUS 1/8 ,, 



EGG 2*2 x 1-5 in. 



Note. "A Sheathbill, Chionis alba, of Antarctic America, 

 obtained in Carlingford Lough, co. Down, on December 2nd, 

 1892, is in the collection of Mr. E. M. Barrington. Living 

 examples have often been sent from the Falkland Islands " 

 (Saunders). (Vide ' Irish Naturalist,' 1893, pp. 151-155, pi. 4.) 



