Diomedea melanophrys in the Ferde Islands. Lt} 
Why has this family no representatives at all in the northern 
part of the Atlantic? There are species of it in the Northern 
Pacific (even sometimes as far north as lat. 644° N.), and in 
the southern part of this ocean, as well as in the South 
Atlantic; only in the northern part of this ocean they are 
entirely wanting, at all events at present.! There are, 
however, many examples on this kind of inequality of 
geovraphical distribution. I shall just note one: Why are 
Hypolais icterina and Alauda cristata common breeding 
birds on this side of the Channel, but only rare and 
accidental visitors in Great Britain? .The cause of this 
“vagary” in distribution that is found among birds as well 
as among other vertebrates, in families as in genera and 
species, is very difficult to find, whether looked upon from 
a biological or a geological point of view; the time when 
these zoo-geographical riddles will be solved is surely far off 
still. As for the Albatrosses, Professor Milne-Edwards (36) 
thinks to find the cause in the distribution of the pelagic 
animals, their food. The Myggenaes Albatross has, however, 
picked up a living for a considerable number of years in the 
north latitudes of the Atlantic, and would scarcely have 
returned constantly if it had experienced a want of food; 
nor does the distribution of the aquatic Mammalia (or of 
certain fishes, eg., Selachus maximus), that essentially feed 
on the same organisms, speak for their being found in less 
abundance there than elsewhere. Perhaps the cause is 
rather the want of really good breeding-places for the 
Albatrosses. The northern part of the Atlantic does not 
abound in high, uninhabited, rocky islets, sufficiently 
isolated, and situated at such a distance from the Continent, 
that these birds might select them for their colonies; the 
Myggenaes Albatross has only proved that a single bird 
can live and breed there, but not that the Ferdées are 
10f Lydekker’s Diomedea anglica (Quart. Journ. Geol. Soc., vol. xlii., 
1886, pp. 366, 367, fig. 2; and Cat. Foss. Birds Brit. Mus., 1891, pp. 189, 
190, fig. 42) from the Upper Pliocene (Red Crag) at Foxhall, Suffolk, only one 
tarso-metatarsus with the associated proximal phalangeal of the fourth digit 
is known. The history of the Myggenaes Albatross shows how careful it is 
necessary to be in drawing inferences from a single discovery. 
