518 



THE DIVING BIRDS — PYGOI'ODES. 



IIab. AVhole Pucific coast of North Aiiierica, I'rom the Aleutian Islands south to Sail Diego, 

 Cal. ; bruwUng as I'ar south as the Faralloiie.s. 



Sp. Chak. Adult : Above, entirely unilbrni iiluinbeous black ; under i)art and sides of the 

 head, with fore ptu't and sides of the neck, plumbeous, blending gradually into the blackish of 



/'. aleuticm. 



the pileum and nape ; a white spot on the lower eyelid. Lower i)arts, from the juguluiu Viack, 

 immaculate white, the sides, beneath the winjjts, and the femoral re^;ion plumbeous. Bill black, 

 the basal third of the mandible yellowish or pale colored ; iris white ; legs and feet bluish and 

 dusky in life, brownish dusky in the dried skin. Young : A)>parently similar to the adult. 



Total length, 8.lK)-9.50 inches ; extent, 1G.(H)-I8.r)() ; wing, 4.75-5.25 ; tail, 1.50-1.75 ; 

 culmen, .75; depth of bill at base, .40; tarsus, 1.00; middle toe, with claw, 1.40. 



%^ 



The only seasonol changes in this very ])lainly colored sjiecies consist apparently in the wrink- 

 ling or covTUgation of the nasal shield, especially on top, in the breeding-season. 



The Aleutian Auk was not met with by Mr. Dall among the Aknitian Islands, nor 

 by Mr. Elliott among the Prybilof Islands. It is an oceanic species, and is presumed 

 to be an inhabitant of both siiores of the Pacific Ocean. 



Dr. Cooper informs me that all the specimens of this bird which he has (d)tained 

 are considerably larger than the measurements given by Mr. Cassin. He f(t\iml twct 



