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Genus MERGULUS. 



Una apud Brisson, Orri. vi. p. 73 (1760). 



Alca apud Linnaeus, Syst. Nat. i. p. 211 (1766). 



Mergulus, Vieillot, Analyse, p. 67 (1816). 



Cephus apud Lesson, Traite d'Orn. p. 639 (1831). 



Arctica apud G. E. Gray, List of Gen. of B. p. 98 (1841). 



This genus contains a single species, which inhabits the northern portions of the Paleearctic and 

 Nearctic Regions, its exact range being given in the following article. In its habits it closely 

 resembles the species included in the genus Alca, being essentially a marine bird ; and, except in 

 the breeding-season, it is seldom seen near or on land, unless driven in by stress of weather. It 

 is said to be seen more often near or amongst drift ice than in the open clear sea ; and numbers 

 will often collect on a piece of floating ice. It feeds on small Crustacea and fish, and appears to 

 obtain its food chiefly by diving ; and though it walks badly, like its allies it flies swiftly and 

 with tolerable ease. It breeds in rocky places, and deposits a single pale greenish-blue egg in a 

 cleft in the rock or amongst the stones and boulders, in such places that the foxes cannot 

 get at it. 



Mergulus alle, the type of the gerius, has the bill much shorter than the head, as broad as 

 high at the base, moderately compressed and decurved towards the end, the tip narrow, blunt, 

 with a slight sinus, the nasal sinus broad, basal, angular, the nostrils basal, oblong, with a horny 

 operculum ; wings short, narrow, pointed, the first quill longest ; tail very short, slightly rounded ; 

 legs very short, rather slender, placed far behind ; tibia bare for a short distance ; tarsus com- 

 pressed, anteriorly scutellate ; hind toe wanting ; anterior toes moderate, connected by webs, the 

 inner much shorter than the outer one, which is very little shorter than the middle one; claws 

 moderate, curved, compressed, acute. 



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