of June, each pair lays two, three, or four eggs; these are of a pale olive or yellowish colour, spotted

with grey, reddish brown, and brownish black. Both sexes incubate by turns, keeping the eggs constantly covered. If disturbed during the breeding season, these Terns are as noisy as any of their congeners, but unlike them remain close over the nest and only go in search of food at regular intervals. After the lapse of fourteen or sixteen days the young make their appearance, and about a fortnight later quit the nest. Even after they are fully fledged they accompany their parents, who tend them with great devotion, and feed them while on the wing, after the manner of Swallows. This species subsists chiefly on shell-fish, beetles, and dragon-flies. The flesh of the Black Terns is tolerably good.

THE WHITE-WINGED TERN.

The White-winged Tern (Hydrochelidon leucoptera) has the body-feathers of a rich deep black; the upper part of the wing is blueish grey; the shoulders and points of the secondary quills are whitish grey, and the rump and tail-feathers white. This species, which closely resembles the Black Tern in size, manners, and habits, is very rare upon the coasts of Great Britain. Temminck states that it frequents the shores of the Mediterranean, and the lakes, rivers, and marshes beyond the Alps, being common about Gibraltar, and Lakes Como, Lugano, and Lucerne, but that it never visits Holland, or North Europe. Nilsson, on the contrary, includes it amongst the birds of Germany and Scandinavia. The food of the White-winged Tern consists of winged and aquatic insects, worms, and sometimes small fishes.

THE WHITE-BEARDED TERN.

The White-bearded Tern (Hydrochelidon leucopareja) has the black upon the head and nape divided from the dark grey lower neck by a broad white stripe; the breast is dark grey, mantle light grey, and belly greyish white. This rare bird was first discovered by M. Natterer, in the marshes of South Hungary, and is but very seldom seen in Great Britain. We are little acquainted with its habits beyond that it subsists upon worms, snails, and winged insects. Yarrell describes the egg as being one inch and a half long, by one and one-eighth broad, with an asparagus-green shell, spotted with brownish black and blueish grey.

THE WHITE OR SILKY TERN.

The White or Silky Tern (Gygis Candida) is a beautiful bird, with slender body, long thin beak, which curves perceptibly upwards, long wings, and deeply excised tail. The feet are small, and the toes furnished with a narrow web; the plumage is of silky softness and pure white; the eye is black, the beak dark blue towards its base and black at the point; the foot is saffron-yellow.

The White Tern inhabits the Pacific Ocean, and is to be met with from Moreton Bay to Cape York. Gould was informed by Mr. Cumming, that on visiting Elizabeth Island, in the South Seas, which is entirely destitute of inhabitants and fresh water, he found this, or an allied species, breeding on a kind of Pandanus, its single egg being deposited on the horizontal branches in a depression, which, although slight, was sufficient to retain it in position, despite the high winds and consequent oscillation to which it was subjected. Mr. Cumming added that the old birds were flying about in thousands, like swarms of bees, and that he noticed several breeding on the same tree. Some of the young birds were hatched and covered with down, and being within reach, he took a few of them in his hand, and after examining, replaced them on their dangerous resting-place, from which it appeared they occasionally fell down and were destroyed, as he observed several lying dead on the ground. Gould also refers to a bird of this genus, and perhaps the same species noticed by Darwin in the Journal of Researches in Geology and Natural History, who, speaking of Keeling Island,