_T is a well-known fact, which moreover impresses 
y itself upon every naturalist during his passage north 
along the coast of Norway, that the number of 
species of birds decreases to an extraordinary extent 
towards the north, while on the other hand the 
number of individuals increases so considerably, 
that hardly anywhere else in our continent do we see bird-life 
more richly displayed, than just when we stand on the furthest 
point of North Europe facing the Arctic Ocean. 
It is especially in the great colonies, ‘‘The Bird Rocks,” 
where this swarming bird-life exists. 
Such bird rocks make their appearance at intervals along the 
whole of the coast of Norway from Stavanger, off and on, up to 
Varangerfjord and the Russian frontier, exactly as we know them 
on the coasts of Scotland and of the Faroe Isles. But while the 
bird-rocks of these districts, the west-European on the one side, 
and the Norwegian on the other, have of course, most of their 
breeding species in common, as for instance the Guillemot and 
Razorbill, the Puffin, the Cormorant and Shag, besides some 
gulls, especially the Kittiwake (or ‘‘ Three-toed Gull,” Fissa 
tvidactyla): it is remarkable that the Norwegian bird-rocks 
wholly lack several species, which form to some extent their chief 
occupants in the west-European district. 
This is not only the case with the more pelagic species, which 
belong to the more open parts of the Atlantic, as for instance the 
two Petrels (Procellaria pelagica, and P. leucorrhoa), the Gannet 
(Sula bassana), and the characteristic Shearwaters (Pu/ffinus anglorum 
and P. majov), which certainly occur occasionally on the Nor- 
I 
