ALCIDjE: auks. 



799 



excavated for the purpose. Auks 

 are all altrices, and are believed 

 to be chiefly monogamous. The 

 young are at first covered with 

 long soft woolly down ; rarely 

 stiffish hairs appear on some parts. 

 The moult is double. The young 

 of tlie year usually difibr from the 

 adults ; the latter usually differ in 

 their summer and winter plumages. 

 A very prevalent feature is the 

 possession of crests or plumes, or 

 elongated feathers of a peculiar 

 shape on the sides of the head. 

 All the species walk badly ; 

 some scarcely walk at all. 

 The position of the legs willi 

 reference to the axis of the 

 body necessitates an Tipright 

 position when standing. The 

 birds appear to rest on their 

 rumps, with the feet extended 

 horizontally before them, most 

 of the tarsus touching the 

 ground. The Puffins, how- 

 ever, and a few others, stand 

 well on their feet. All the 

 species but one fly well, with 

 rapid vigorous motion of the 

 wings, in a straight, firm, 

 well - sustained course. All 

 progress on or under tli«^ 

 water with the utmost focility. 

 They are very silent birds: 

 the voice is rough and harsh ; 

 the notes are monotoned. 

 They feed exclusively upon 

 Fig. 532. — A needle rock tenanted by Cormorants (p. 728, No. 757), Auks, animal substances procured 

 etc. (Designed by H. W. Elliott. From Harper Brothers.) ^,^^^^ ^1^^ water. 



The family is divisible into two subfamilies according to the feathering of the nostrils- 

 and other characters. 



Analysis of Subfamilies and Genera 

 Phalkridin^. Nostrils naked, remote from feathers. Bill of variable shape, always compressed, 

 higher than wide, as far as known appendaged with deciduous elenients. Head nearly always crested. 

 Xo great seasonal changes of plumage. 



Kyelids with deciduous appendages. No crests. Bill extremely high and thin; culmen witli one 

 curve; l)oth mandililes grooved. A rosette at angle ot mouth. Covering of bill moulted in 7-9 



pieces. Inner lateral claw enlarged. Tarsus scutellate in front Fratercula 337 



Eyelids simple Long lateral crests. Bill extremely high and thin; culmen with two curves; upper 

 manililile crooveil, under smooth. A rosette at angle of mouth. Covering of bill moulted in 7 pieces. 



Inner lateral claw enlarged. Tarsus scutellate in front Lunda 338 



Eyelids simple. Lateral crests. Bill with a deciduous horn at l>aso of upper mandible. No rosette. 



