On the whole they have a very great resemblance to some of the smaller terns both in flight and habits.

Nothing is more certain, however, than that these birds are closely allied to the plovers, as also to members of the foregoing super-family, especially the Chionis, with which they agree in lacking occipital foramina and basipterygoid processes.

That Linnaeus placed the common pratin- cole ( Glareola pratincola) in his genus Hirundo, on account of its forked tail and deeply split mouth, is perhaps not so strange.

But that Sundevall, as late as 1874, denied the Charadriine affinities entirely, giving it place in the family Caprimul- ginae as an aberrant group of goat-suckers, referring, as he did, to the large size of the eyes, the form of the bill, the pectination of the long middle claw, and the somewhat sideways position of the hind toe, shows how unsafe it is to rely upon external char- acters alone in cases of intricate relationship.

The species represented in the accom- panying cut, Fig 41, is the common pratincole, which is a regular summer visitor to the Mediterranean sub-region and the valley of the lower Danube, sometimes stragglino- northwards as far as Denmark and the British Islands.