FAMILY ALCID.E. AUKS, PUFFINS, AND MURKES. 29 



Back, with white spots ; throat, white or whitish (Immiiture or winter). 



Gacia Inmme. Red=throated Loon. 



See No. 7. 



Back, without distinct white spots ; tiie feathers, edged with asliy; tlnoat, wliite or 

 iisky (^iiuniauire or winter). Gavia arctirus. Black=throated Loon. 



See No. 6. 



* Group 3. Wing, over 15 inches long. 



Feet, webbed; head, black, in adult; liead, j,a-a\' ; throat, wliitlsli, in inunature. 



Ufi)uttur imbcr. Loon. 

 See No. 5. 



FAMILY ALCID/E. 

 Auks, Puffins, and Murres. 



Toes, three; no hind toe (hallux); toes, palmate (full 

 webbed) ; nostrils, separate, and not tubular. 



* Group 1. Wing, less than 5 inches long. 



Winter pi umaije : Upper parts, ])lack : underi)arts, white. In siDiimrr : The 

 areast, throat, and sides of the head and neck, sooty brown. 



AUe (die. Dovekie. Little Auk. 



See No. 17. 



^§^^: 



* Group 2. Wing, 5.50 to 6.50 inches long. 



^ 



Bill, parrot like; underparts, wliite; back, black; usually a black 

 •o'.jar. Fraten-uhx nrctica. Puffin. Sea Parrot. 



See No. 9. 



Adult in sHinmer : General plumage, black, a white patch on 

 ;he shoulder; basal half of the greater wing coverts (feathers 

 tormina; the wliite patch on the wiiii^), black. Winter birds have 

 the underparts white, and the upper ])arts, black and white. 



Cepphus ijrijllc. Black Guillemot. Sea Pigeon. 



Sec No, n. 



Similar to Black Guillemot, but has the wing coverts (feathers forming the white wing 

 patch ) entirely white and not with basal half black. 



Immature and winter birds (except wing coverts), resembling tlie Black (iuillemot. 



Cepphus niandtii. Mandt's Guillemot. 

 See No. 12. 



* For directions for measurement, see page 0. 



