Genus URINATOR Clvier. (Page 6, pi. II., fig. 1.) 

 /Species. 

 Common Ch.4RActers. — Above blackish or slaty, beneath wbito. In summer, 

 upper parts spotted or speckled with white, the tiiroat and fore-neck blackish or 

 chestnut. In winter, and in young, U])per parts without white markings, and throat 

 and fore-neck white like rest of lower parts. Downy young uniform soot)' grayish, 

 the belly white. J}^est built on ground at edge of marsh or lake. Eggs 2, elongate- 

 ovate, deep brown or olive, rather sparsely speckled or spotted with dai-k brown 

 and blackish. 



a'. Tarsus shorter than inner toe with claw ; fore-neck blackish in summer. 



b'. Distance from base of culmen to anterior point of loral feathers, above 

 nostrils, greater than the distance from the latter point to anterior bor- 

 der of nostrils. Summer plumage with head and neck black all round, 

 the middle of the fore-neck and sides of lower neck each crossed by a 

 bar or transverse series of white streaks, 

 c". Basal depth of bill' not less than one-third exposed culmen ; bill in adult 

 blackish (almost whollj* deep black in summer) ; head and neck 

 glossed with velvet)' green ; white spots on scapulars broad as long ; 

 length 2S.00-36.00; wing 13.00-15.25 (14.00); culmen 2.75-3.50 

 (3.07) ; depth of bill through base .90-1.05 (.96). Eggs 3.52 X 

 2.27. Htib. Northern part of northern hemisphere, breeding from 



northern United States northward 7. U. imber (Gcnn). Loon. 



c'. Basal depth of bill less than one-third exposed culmen ; bill in adult 

 whitish (almost wholly yellowish \vhite iu summer) ; head and 

 neck glossed with velvety violet-blue ; white spots on scapulars de- 

 cidedly longer than broad ; length about 35.00-38.00 ; wing 14.85- 

 15.45 (15.11) ; culmen 3.50-3.G5 (3.59) ; depth of bill through ba.'se 

 1.00-1.20 (1.09). Hal. Western Arctic America and northeastern 



Asia 8. U. adamsii (Gray). Yellow-billed Loon. 



6'. Distance from base of culmen to anterior point of loral feathers, not greater 

 than distance from the latter point to anterior extremity of nostril. 

 Summer plumage with upper part of head and hind part of neck graj'- 

 ish ; throat and fore-neck black, without white streaks, but several lon- 

 gitudinal series of the latter down the side of the neck, between the 

 black and the gray. 

 c*. Fore-neck and under side of neck glossed with velvety purple ; occi- 

 put and hind-neck deep graj*, almost plumbeous. Length 26.00- 

 29.00; wing 12.15-13.20 (12.55); culmen 2.50-2.85 (2.60),^ depth of 

 bill at base, .75-.80 (.78). Eggs 3.09 X 1-96. Hah. Northern por- 

 tions of northern hemisphere, breeding in Arctic regions ; in North 

 America, south, in winter, to extreme northern United States, east 

 of the Eocky Mountains. 



9. U. arcticus (Lixx.). Black-throated Loon. 



1 At base of esposeU culmen. 



