120 
allen’s naturalist’s library. 
writes; “So far as is known, wherever one form occurs, both 
in the Atlantic and Pacific, the other is found with it, the 
proportion of Ringed Guillemots varying from one in five to 
one in twelve of the Common Guillemot.” He also states that 
the two forms have been seen paired together, “and the white 
line behind the eye is said to vary in length, leading to the 
supposition that intermediate forms are found.” In all the 
specimens as yet examined by me, I have found no trace of 
such intermediate forms, and the inter-breeding, if such there 
be, between the Bridled and the Common Guillemot, is no 
more than one might expect to occur lietween two species alike 
in size and habits. Such instances are known to occur in other 
groups of birds, as is evidenced by the Crows, Dippers, and 
Wagtails. I confess, however, that I should like to have in- 
disputable evidence that the two Guillemots inter-breed. It 
seems to me that such satisfactory evidence must be very 
difficult to obtain. 
'I'here is no recorded difference in the habits or nidification 
of the Bridled Guillemot to those of the Common Guillemot. 
III. brunnich’s guille.mot. uria bruennichi. 
Uria brunnkhii, Sabine, Trans. Linn. Soc. xii. p. 538 (1818); 
Macgill. Brit. B. v. p. 314 (1852); Saunders, ed. Yarrell’s 
Brit. B. iv. p. 76 (1884) ; id. Man. Brit. B. p. 685 (1889) ; 
Lilford, Col. P’ig. Brit. B. part xxxii. (1896). 
Aka bruennkhii, Dresser, B. Etir. viii. p. 575, pi. 622 (1877). 
Lomvia bruennichi, B. O. U. List Brit. B. p. 207 (1883). 
Aka troile brunnkhi, Seebohm, Hist. Brit. B. iii. p. 388 (1885). 
Adult Male in Breeding Plumag-e. — General colour above glossy 
black ; the head like the back ; the lores, feathers above the 
eye, sides of face, throat and sides of neck rich chocolate- 
brown, contrasting with the black of the upper parts ; wings 
black, the secondaries tipped with white, forming a wing-bar ; 
the outer primaries with white bases to the shafts ; tail black ; 
under surface pure white, from the lower throat dowmwards, a 
sharp line of demarc.ation crossing to the sides of the chest, 
and forming a blunt triangle on the lower throat ; under wing- 
coverts white, those near the edge of the wing light brown 7 
