216 AVES : PYGOPODES. — XXXI. 



bluish, with dark band; youn^ and winter phimafj^c difForent, the 

 bill unniarkod, but the bird rescuibles nothing; els*-. L. 14. W. T). 

 B. 1 . Whole of America, abundant. {Lat., podex, rump ; pes, foot.) 



Family CXXV. GAVIID^. (The Loons.) 



Bill lonj;, stronnj, taperin<r, acute, wholly hard ; nostrils linear. 

 Head densely and evenly feathered, without ruffs or naked s[)!u;es; 

 eye lar^'e. Feet 4-toed, palmate ; tarsus reticulate, strongly com- 

 pressed. Winjjs comparatively long and stronj^ ; tail short but 

 well developed. Precocial. (lenus 1 ; species 5. Birds (tf lar^e 

 size, with strong powers of llight, and pre-eminent in swimminir and 

 divinix, but scarcely able to walk ; they are mi'^ratory, breedin^r north- 

 ward, but coming 8. in winter; the voice is singularly sharp and wild. 



321. GAVIA Forster. 



o. Tarsus shorter than middle toe, without claw. 



631. G. imber (Gunner). Common Loon. Diver. Black; 

 breast and below chiefly white ; head and neck iridescent, black in 

 summer ; a patch of white streaks on each side of neck and on the 

 throat ; back with many white spots ; 9 duller, brownish above, 

 without the head markings. L. 28 to 36. W. 14. Ts. 3. B. 3. 

 Northern Hemisphere; whole U. S. in winter. (Eu.) (Norwegian 

 name.) 



632. O. arctica (L.) Black-tiiuoated Loon. Similar, but 

 liead and neck behind i)luish or hoary gray ; foreneck purplish 

 l)lack, with a crescent of white streaks; 9 duller. L. 2.S. W. 12^. 

 B. 2|. Northern Hemisphere, not common in L'. S. (Eu.) 



aa. Tarsus loiifrer than middle toe witii claw. 



633. G. lumme ((junner). Rkd-turoated Loon. Blackish, 

 streaked on neck, chiefly white below; head and neck mostly bluish 

 gray; throat with a large chestnut patch in siiininer; 9 duller. 

 L. 27. W. 11. B. 2. Northern regions, U. S. in winter. (Eu.) 

 (Norwegian name.) 



Family CXXVL AL,CID^. (Tin: Aiks.) 

 Feet palmate, thn-e-toed; tarsus relictilate or partly scutcllato; 

 sulTrago naked; claws ordinary ; bill and nostrils various; tail pcr- 

 fi'ct. of few fcatlu-rs; lores feathered; legs variable, set far back; 

 color variable, the hea<l often with curly crests; altricial; eggs few. 

 (Jencra 12; species about 35, living al)out rocks on rugged shores 

 in Xorthern regions. Most of them fly well and all swim on or 

 under water with eijual ea.se. They feed chiefly on fishis. 



a. Inner claw much lar^jcrand more cnrvcfl than the others; corner of month 

 with a " rosette " of tliick naked skin; billf^rettlly comi)res8ed, almost as 

 deep as long. {yKtliiciilimr.) 



