534 DIVING BIRDS. 
wings and its relatively shorter beak, in which there are but two or three grooves 
on the lower mandible, and these indistinctly marked. Lacking the large white 
spot in front of the eye characterising the great auk, the adult razorbill in summer 
has a narrow white line extending from the beak to the eye. While in summer 
the chin and throat of the adult are brown, and the head, hind-neck, and upper- 
parts black, with the under-parts white, in the winter dress the white extends 
upwards to the throat, chin, and sides of the head, and the plumage of the upper- 
parts is browner. The razorbill is common to the coasts and islands of both sides 
of the North Atlantic, ranging as far north as latitude 70° in Greenland, while 
in winter it reaches Gibraltar, from whence it wanders a considerable distance up 
the Mediterranean. Resident throughout the year in the British seas, it breeds on 
all suitable rocky coasts, from the north of France to the North Cape, generally in 
large colonies. Concerning its breeding-habits, we find it stated in the third 
edition of Yarrell’s British Birds that “about the middle or latter part of March 
in the South of England, and early in April in the northern portions of our islands, 
the razorbills, guillemots, and puffins converge to particular points, where, from 
the numbers that congregate, and the bustle apparent among them, confusion of 
interests might be expected. It will, however, be found that, as a rule, the 
guillemots occupy one station or line of ledges on the rock; the razorbills another ; 
the puffins a third; the kittiwake-gulls a fourth; whilst the most inaccessible crags 
seem to be left for the use of the herring-gulls. The razorbills generally select 
the higher and rougher ledges, and they are partial to crevices, their eggs being 
sometimes deposited so far in that it is no easy matter to get at them; at other 
times they lay their eggs on the broader shelves along with the guillemots, but 
not so closely together.” 
Closely allied, both as regards structure, the colour, and seasonal 
chance of their plumage, and habits, to the razorbills, the guillemots 
differ by their more slender and straighter beak, in which there are no oblique 
transverse grooves, while the upper mandible is slightly curved near the point, 
and has a small notch on the side. The basal nostrils are partially closed by a 
membrane, which is itself partly feathered. There is still some degree of 
uncertainty as to the number of species of the typical guillemots, some writers, 
like Mr. Seebohm, recognising but one, while others, like Dr. Sharpe, admit 
several. Whether, however, we regard them as species or varieties, all the forms 
are characterised by the white plumage of the under-parts; this white area in 
the summer dress stopping short at the base of the throat, but in winter extending 
upwards, as in the razorbill, to the throat, chin, and sides of the head. In the 
typical form of the common guillemot (Uria troile) which inhabits both sides of 
the North Atlantic, the beak is of considerable length, and the head is of a 
uniform smoky brown. It is replaced in the Pacific by a somewhat larger form, 
known as the Californian guillemot. Both in the Atlantic and Pacific there are 
also certain guillemots, like the one in the foreground of the cut, characterised 
by the presence of a white streak extending backwards from the eye, and a white 
ring round the eye itself. Formerly regarded as indicating a distinct species, 
these ringed guillemots, as they are commonly ealled, are now generally con- 
sidered to be merely sports. Pallas’s guillemot, of Behring Sea and other parts 
Guillemots. 
