One of the nests containing three eggs had also a stone about the size of an egg placed in the middle of it. A clutch of three averaged 1·61 in. by 1·16 in.; but measurements of two isolated clutches are not much on which to base arguments. I did not notice any nestling Terns.
Lesser Tern (S. minuta).—Walney Island. I found one colony of these birds on a part of the beach. I examined two nests containing two and three eggs respectively. Both nests were on the shingle, just above high-water line; and the clutch of two eggs was amongst some large pebbles, really only just lying in the depression caused by the shape of the stones, without any attempt at scratching out a hollow. There was no kind of lining in either case, the eggs being laid on the bare stones.
Ravenglass. Here there was also a colony of Lesser Terns breeding on a shingly piece of beach to the north of the estuary of the Esk. I did not search for nests, but I accidentally found a single egg laid on the pebbles in a small hollow just above high-water mark.
I saw no nestlings of this species.
Black-headed Gull (Larus ridibundus).—Walney Island. There are large colonies of these birds at each end of the island, both on the sand-hills and on the moss. The coarse grass growing on the sand-hills forms little ridges and steps on the sides of the hummocks, and make a favourite resting-place for the Gulls' nests, which are thus built, as it were, in terraces. The dead blades of the grass give the bulk of the building material that the birds require, and with it they make, as a rule, a fairly substantial but shallow cup-shaped nest, resting directly on the sand. Amongst the colonies on the moss there will often be nests with a considerable foundation of rubbish and dead sticks, varying from a few inches to a foot in height. The biggest I noticed measured fully two feet across the base, and was a good twelve inches high. The rule with the nests on the moss was to have a foundation of sticks under the cup of grass, while the method in the sand-hills was for the cup of grass to be laid right on the sand without any materials underneath it. The inside measurements of the nests varied from 6–7 in. diameter by 1½–2 in. deep. Most of them had clutches of three eggs.
