The BLACK-HEADED GULLS (_Chroicocephalus_) constitute a group whose most conspicuous character is that, when in their nuptial dress, their head is covered, as it were, with a black cap. We can hardly, from this circumstance, regard them as a distinct sub-family; nevertheless, they present certain peculiarities not common to the race. All these birds inhabit temperate climates, and seldom or never appear in the northern regions visited by so many other species. The food of the Black-headed Gulls consists principally of insects and small fishes; however, they by no means despise small quadrupeds or carrion. Insects they generally catch in the water and pick from the surface of the ground, but occasionally they take them while on the wing. The young are fed almost exclusively on insects. THE LAUGHING GULL. The LAUGHING GULL (_Chroicocephalus ridibundus_). The adult in summer has the head, occiput, and upper part of the neck of a dark brown, the colour being most intense when first assumed, and becoming lighter by time and wear; the sides and back of the neck are pure white; the back, wing-covers, secondaries, and tertials, uniform French grey; the first three quill primaries white on the shafts and webs, but margined with black; the fourth white on the outer web, grey on the inner web, and edged with black; the fifth and sixth grey on both webs, the edge of the inner or broader web and the point black; tail-covers and tail-feathers white; front of the neck, breast, and all the under surface of the body and tail pure white; legs and feet, like the beak, are vermilion-red; irides hazel; eyelids orange. The adult bird in winter has the head only slightly marked with a dusky patch at the ear-covers. The young are brownish on the upper parts of the body. This species is sixteen inches long, and thirty-six inches broad; the wing measures twelve and tail five inches. With regard to the change in colour of the head according to the season of the year, Mr. Yarrell observes: "A Gull in the collection at the Gardens of the Zoological Society began to change colour on the head, from white to dark brown, on the 11th of March; it was a change of colour, and not an act of moulting; no feather was shed, and the change was completed in five days." The Laughing Gull is plentiful from 30° to 60° north latitude, and within this zone it rears its young. It is met with pretty nearly in equal numbers upon suitable inland waters in Europe, Asia, and America. In the South of Europe it is seen throughout the year; in Central Europe and Great Britain it is only a visitor, leaving us in October and November to take up its quarters upon the shores of the Mediterranean. It is, however, said to be a constant resident in Ireland. [Illustration: THE LAUGHING GULL (_Chroicocephalus ridibundus_).]