ALCIDAE 315 



and feet red, and a white streak marking each cheek. In the 

 winter and immature plumage the under parts are entirely, and 

 the head partially white, throughout the genus. 



Of fossil Laridae Halctjornis occurs in the Lower Eocene of 

 England, Aegialornis ^ in the Upper Eocene of France ; while 

 the Lower Miocene of the latter country, the Middle Miocene 

 of Germany, and the Pliocene of Oregon furnish Larus. 



Fam. VIII. Alcidae. The Sub-order Alcae contains only 

 this Family, or the Auks, wherein the body is heavy and compact, 

 the head large, the plumage close and elastic. The stout bill 

 varies extraordinarily, as will be seen under the various species. 

 The abbreviated metatarsus is reticulated, usually with a row of 

 scutellae in front ; the long anterior toes are fully webbed, the 

 hallux is absent or rudimentary, the claws are stout, acute, and 

 slightly curved. The wings are very short,. and the Great Auk 

 was absolutely flightless ; but most species fly strongly and rapidly 

 to varying distances, the pinions not being flipper-like as in the 

 Penguins, to which these birds have no affinity; like them, however, 

 they commonly sit upright upon the metatarsus, and walk awk- 

 wardly from the feet being placed so far back, while they swim and 

 dive to perfection. The primaries are eleven, the secondaries from 

 fifteen to nineteen. The short tail may be rounded as in Uria, 

 or graduated with pointed rectrices as in Alca ; the quills num- 

 bering twelve, except in A. impennis, which has eighteen. The 

 fureula is U-shaped, the syrinx tracheo-bronchial, the tongue 

 lanceolate ; the nostrils covered with feathers in Aha, Uria and 

 Mcrgulus, and with a horny membrane elsewhere are pervious. 

 An aftershaft is present, and down is plentiful on both adults and 

 nestlings, being in the latter fluffy, and of a black, grey, or 

 brown colour, sometimes relieved by white. Elongated feathers, 

 crests, and horny outgrowths are common, as described below. 



Auks are entirely pelagic birds, breeding from the Polar Seas 

 southwards to Japan, Lower California, Maine, and the Berlengas 

 off the Tagus, while wandering further in winter ; but the North 

 Pacific may certainly be considered their headquarters. In the 

 case of the British species a small proportion remain near shore 

 after the autumn, but it seems to be quite uncertain where the 

 jnajority spend the colder months. The members of this Family 

 can hardly be called gregarious, except in the breeding time, 

 ^ Since referred hy Milne-Edwards to the Cypselidae as Tacliyornis. 



