18 The Bird Rock Group. 
haunts of the birds during the egg-laying season. It is stated 
that some twenty years ago 30,000 dozen Murres’ eggs were gath- 
ered annually on the Farallone Islands and sold in the San Fran- 
cisco markets. Asa result of this wholesale robbing, the birds 
decreased in numbers so rapidly that the United States Govern- 
ment forbade their further molestation. It is greatly to be hoped 
that the Canadian Government will soon take steps to afford simi- 
lar protection to the Murres of Bird Rock. 
Two species of Murres inhabit Bird Rock, the Common Murre 
(Uria troile) and Briinnich’s Murre (Uria lomvia). To the 
casual observer the differences distinguishing them are not at 
once apparent, and the presence of two such closely related 
birds, of similar habits, in the same place, is an interesting illus- 
tration of the retention of specific differences under circumstances 
unusually favorable for interbreeding. 
The Common Murre has a longer, more slender bill and 
browner head than Briinnich’s Murre, which has a relatively 
short and thick bill with the basal edges of the lower mandible 
grayish and swollen, and the head dark. The downy young of 
the Common Murre are sooty black, sprinkled with white; those 
of Briinnich’s Murre are decidedly browner. The Common 
Murre breeds in the North Atlantic from Bird Rock and the 
British Islands northward. In winter it ranges southward to 
the coasts of Massachusetts and northern Africa. 
Briinnich’s Murre breeds from Bird Rock northward, but is 
rare in the eastern Atlantic. In winter it is found occasionally 
as far south as New Jersey, and, sometimes it reaches the interior 
states as far west as Michigan, by way of the St. Lawrence River 
and the Great Lakes. 
Some Murres have a white ring around the eye extending 
backward in a white stripe behind it. They are known as 
‘“Spectacled Murres,’’ but whether they constitute a distinct 
species, or are merely an individual variation, is as yet unknown. 
One individual of this kind is shown in the group. 
Razor-billed Auk (Ala torda). The Razor-bill is the nearest 
existing relative of the extinct Great Auk, which it resembles in 
general appearance, but from which it differs in possessing the 
power of flight. This species lays its single egg, which is more 
elliptical than that of the Murres, in natural cavities or other- 
