The present species of Diver (much smaller than the preceding), the _Colymbus arcticus_ of Linnæus and most other writers, is the rarest of the three that visit the British Islands regularly, and perhaps we might also say the most beautiful in nuptial dress. All its showy colours and patterns, however, are on the head, neck, and upper parts, the under surface being white. The head is gray, the throat patch black, above which is a semi-collar of white striped vertically with black; the sides of the neck are also striped with black and white; whilst the black upper parts of the body are conspicuously marked with a regular series of nearly square white spots, becoming oval in shape on the wing coverts: the bill is black, the irides crimson. After the autumn moult all this finery is lost, and the upper parts become a nearly uniform blackish-brown. This Diver breeds sparingly in various parts of the Hebrides and the Highlands, from Argyll to Caithness; elsewhere it is only known as a winter visitor. In many of its habits it closely resembles the preceding species. It is exclusively aquatic, only seeking the land during the breeding season, but is, perhaps, not quite so oceanic as that bird in the winter, when it not unfrequently haunts inland waters. It dives with equal skill, flies with the same powerful rapidity, and utters during the nesting season very similar unearthly cries. Fish form the chief food of this Diver, but it is said also to capture frogs. Most of the examples of this Diver that are seen close in-shore (on our eastern and southern coasts principally) during winter are immature, the older birds as a rule keeping further out to sea. The Black-throated Diver indulges in the same peculiar habit of gradually sinking its body in the sea when alarmed, and will frequently seek to escape pursuit by diving outright, and swimming under water for a considerable distance.