Page:Natural History, Birds.djvu/327

314 even in the form of the beak, straight, slender, and swelling towards the tip, as well as in their internal anatomy, they shew a manifest approach. The typical Gulls are much more land-birds than any others of their Order: those of the subgenus Xema in particular roam much inland, feed on insects and worms, build their nests among herbage in low meadows near the sea, lay eggs of an olive colour marked with large brown spots, and undergo seasonal changes of plumage; all of which might be predicated of the Charadriadæ.

The characters of the Family may be thus summed up: the beak is slender, compressed, gradually, not abruptly bent; the nostrils pierced in the middle of the mandible: the wings are very long and pointed; the hind toe elevated, very small, and not united by a membrane. The prevailing colour of the plumage is white, often varied on the upper parts by a pearly grey, or black.

These birds are found in all parts of the world, feeding greedily on all kinds of animal substances; others, as already remarked, seek their food in the interior of the land, which consists of slugs, worms, and the larvæ of insects. Some few are bold and cunning, attacking other marine birds, and forcing them to disgorge the fish they have swallowed, which these then snap up before it reaches the sea. In this genus the beak is strong, hard, compressed, cutting, slightly curved towards the point; the lower mandible with a strong angle: the nostrils lateral, near the middle of the beak,