486 



THE DIVING I3IKDS — rYGOPODEri. 



hmi 



i,\\ 



northward. On the Pacific side the typical form replaced by the nrra (Prybilof Islands, Kadiak, 

 Aleutians, Kaintschatka, etc.). 



a. Lomvia. 



Sp. Char. Adult, hncdhuj-idnmafje : Entire upper parts, including pileum and nape, glossy 

 fuliginous-black, the secondaries narrowly tipped with white ; sides and under part of head and 

 neck rich velvety dark snuff-brown, shading gradually into the black above it. Lower parts con- 

 tinuous white, ending anteriorly, on the juguluni, in an obtuse angle, extending a greater or less 



distance into the dark brown of the fore- 

 neck ; outer webs of exterior feathers of the 

 sides and flanks broadly edged with sooty 

 black. Bill uniform deep black, the basal 

 half of the maxillary tomium plumbeous, 

 sometimes conspicuously light colored ; iris 

 brown ; legs and feet dusky brown in the 

 dried skin. JVinter plumage : Whole throat, 

 foreneck, auricular region, and sides of the 

 occiput white, the upper border of the iui- 

 riculars cro.ssed by a narrow blackish stripe ; 

 white latero-occipital space and lower i)art 

 of foreneck, faintly mottled transversely 

 with dusky. Upper parts as in the summer 

 plumage. Young: Similar to the winter 

 plumage, but without white on the sides of 

 the occiput. Downy young : Fuliginous- 

 dusky, the lower parts white ceTitrally, 

 shading exteriorly into smoky grayish ; head and neck variegated with irregular pale smoky buff 

 streaks and filamentous downy tufts of the same color. 



Total length, about 18.50 inches; extent, 30,00 to 32.00; wing, 7.45-8 80 (average, i 8.24); 

 culmen, 1.40-1.50 (1.45); gonys, .75-.90 (.83); depth of bill, through angle, .52-.58 (.55); tarsus, 

 1.40-1.55 (1.45); middle toe, without claw, 1.65-1.75 (1.70). 



b. Arra. 



Sp. Char. Precisely similar in colors, in all stages of jdumage, to typical lomvia, l)ut decidedly 

 larger in all its measurements, and with the maxillary tomium less distinctly light colored toward 

 the base. 



U. lomvia, summer plumage. 



U. lomvia arra. 



Wing, 8.15-9.25 inches (average, 8.71); culmen, 1.45-1.75 (1.65); gonys, .85-1.00 (.92); depth 

 of bill through angle, .55-.60 (.58); tarsus, 1.45-1.60 (1.51); middle toe, without claw, 1.70-1.90 

 (1.81). 



Though by many the Briinnich's Guillenict has been regarded as merely a local 

 race of the common species, it has of late become generally regarded as having good 

 claims to be considered a distinct species. It appears to have to a large degree the 

 same distribution as lias the trollc, and so far as it has been observed, the same liabits. 



1 Of cij^'lit adult uxaniiiles. 



