URINATORID/E — THE LOONS — UEINATOR. 



451 



the plumage also slightly diflcreut. Bill very large, much compressed, the terminal half tapering 

 rapitlly from the well-defined or even prominent angle at the base of the gonys ; culmen almost 

 perfectly straight ; feathering on sides of maxilla reaching nearly to anterior end of the nostrils. 

 Adult : Upper half of the head (including loral, orbital, and auricular regions), with nape, dull black, 

 with slight brownish green reflections ; lower half of head (including malar region, chin, and throat), 

 with foreneck and lower neck, all round, blue-l)lack, with violet-blue reflections ; foreneck crossed 

 by a bar of white longitudinal spots, these much broader than in U. immer ; sides of the neck, 

 below this bar, with a transverse broad patch of similar markings. Upper parts black, variegated 

 by white dots, as in U. immer, but those of the scapulars much longer than broad, instead of 

 nearly square ; lower parts white, the sides of the jugulum streaked with black ; sides and flanks 



U. Adamsi. 



blue-black, variegated by small round dots of white. Bill dull yellowish, dusky basally, inclining 

 to ivory-white terminally ; iris " light reddish brown ; legs and feet olivaceous." Younrj : Similar 

 to that of U. immer, but larger, the bill larger, deeper, more compressed, and with a decided 

 gonydeal angle ; under side of head and neck gi-ayish white, clouded \vith sooty grayish brown. 



Wing, 14.85-15.45 inches (average, 15.11); culmen, 3.50-3.65 (3.59); depth of bill through 

 base, 1.00-1.20 (1.09); tarsus, 3.25-3.55 (3.41); outer toe, 4.15-4.65 (4.34). (Six adults.) 



So far as American specimens are concerned, this species appears to be perfectly distinct from 

 U. immer, no examples at all intermediate occurring in large series of the two. It is a much 

 larger bird in all its measurements, the bill is very differently shaped, and the plumage quite 

 distinct in the points referred to above. 



In "Birds of America," Vol. VII. p. 291, Audubon proposes a name, Cohjmbus Richardsoni, 

 which some writers have considered as belonging to the present bird ; but although specimens of 

 what were unquestionably U. Adamsii, collected by Captain Ross, are mentioned in the same 

 paragraph, the name Cohjmbus Richardsoni was clearly based upon " a very large and handsomely 

 crested. Diver" which Dr. Richardson saw during one of his northern journeys, and which, "although 

 somewhat prematurely," Audubon proposed " honoring with the name of Colymbus Richardsoni." 



Mr. Audubon (" Birds of America," VII. 291) refers to a specimeu of a Loon given 

 to him by Captain James Clark Ross which had been procured in a very high latitude, 

 and which, upon inspection, he found to differ from the common Northern Diver in 

 having the point of the bill slightly recurved, and of a fine yellow tint : and Dr. 

 Richardson also informed him that he had met with a very large and handsomely 

 crested Diver. Regarding the latter as a new and undescribed species, Audubon 

 proposed for it the name of Colymbus Richardsoni. This, however, could scarcely 



