i4i British Birds with their Nests and Eggs. 



The adult in breeding dress has the bill black, inside of bill yellow, of mouth 

 flesh colour ; iris dark brown ; head and neck, all round, chocolate-brown, slightly 

 daiker on the top of the head, terminating on the lower neck in front in a 

 rounded arch; rest of the upper parts and the wings blackish-brown; primaries 

 with the inner part of the inner web light coloured, and the shafts of most of 

 them light or whitish horn colour ; secondaries tipped with white ; neck below 

 the brown breast, and under parts generally, white, streaked on the sides of the 

 body and flanks with dusk}-, the feathers being parti- coloured ; legs and feet 

 blackish. 



In winter the bill is horn colour, darker towards the tip. The chin, throat 

 and front of the neck become white, as well as the sides of the face, but the 

 feathers below the eye remain dark, and a dark patch behind and below the eye 

 is prolonged backwards and downwards, in a line along the furrow or groove in 

 the feathers, covering the orifice of the ear, and dividing a white or slightly 

 mottled patch on the sides of the head (extending to sides of nape) from the white 

 of the lower face and sides of the throat ; a band, more or less dusk}% across the 

 throat appears very early in spring ; the upper parts are rather darker and more 

 slaty than in summer ; legs and toes pale brown on the upper or inner sides 

 (with a faint tinge of purple in some cases), joints and webs dusky; under- or 

 out- side dusky ; claws dark horn ; the inside and upper- side of the tarsus and 

 toes is sometimes yellowish-brown. 



Young birds have the throat and the sides of the head mottled with dusky, 

 and their bills are smaller and lighter coloured. 



The summer dress is in some cases assumed very early in the year. Examples 

 in this dress have been recorded as occurring in the latter part of December and 

 in January. 



The change to winter dress also occurs at an early date, and soon after the 

 birds leave the rocks and go to sea. At this season they are said to be incapable 

 of flight for a short time, from shedding many of their quill feathers at once. 



The sexes are similar in plumage. 



The total length varies somewhat, but is usually about 17*5 inches; wing 7*5 

 inches. I have weighed a Guillemot in winter which turned the scale at a fraction 

 under 30 ounces, and another, in good condition, which weighed only 22*5 ounces. 

 But the finest Guillemot I ever handled measured i8'6o inches in total length, 

 and weighed 39/5 ounces. Its vigour was manifested by two partly black (party- 

 coloured) feathers on different parts of its belly. 



The culmen varies in length from i"j6 to i"45 inches; the height of the 

 bill at the angle of the under mandibles from '55 to "40 inch, and the thickness 



