In disposition and mode of life these gulls differ much from each other. The glaucous gull is sufficiently strong to be able to defend its eggs and young against the attack of the mountain fox. It therefore breeds commonly on the summits of easily accessible small cliffs, hillocks or heaps of stones, preferably in the neighbourhood of "loomeries" or on fowl-islands, where the young of the neighbouring birds offer an opportunity for prey and hunting during the season when its own young are being fed. Sometimes, as for instance at Brandywine Bay on Spitzbergen, the glaucous gull breeds in great flocks on the ledges of steep fell-sides, right in the midst of Bruennich's guillemots. On Bear Island I have seen it hatch on the very beach, at a place, for instance, under the arch of a waterfall leaping down from a precipitous cliff. The nests, which, to judge from the quantity of birds' dung in their neighbourhood, are used for a long succession of years, are placed in a depression in the rock or the ground, and lined with a little straw or a feather or two. The number of the eggs is three or four. After boiling they show a jellylike, half transparent white, and a reddish yellow, and are exceedingly delicious. The young birds have white flesh, resembling chicken. The burgomaster is common everywhere along the coasts of Novaya Zemlya and Spitzbergen. Yet I have not seen the nest of this gull on the north coast of North East Land or on the Seven Islands. [Illustration: A. THE KITTIWAKE B. THE IVORY GULL. Swedish, Kryckia. (Larus tridactylus, L.) Swedish, Ismaos (Larus eburneus, L.) ]