ALASKA. 211 



635. L.omvia arra, (Pall.) Covus.—Thklc-hiUed GuiUemot. "Anie." 

 Cepphus arra, Pall. Zoog. R.-A., ii, 347, (1811.) 

 Uria arra, Cass. Pioc. Pbila. Acad., 324, (1862.) 

 (Also, TJria hriinniclni, &c., of authors refeniug to tbe North Pacific 

 thick-billed bird.) 



It is au iDterestiug fact that these specimeus, luiqnestionably 

 of tbe "thick-billed" guillemot, do uot exhibit the extreme 

 shortness and stoutness of bill showii by those of the North 

 Atlantic, the bill being almost exactly intermediate. With the 

 chord of culmen about 1| inches long, the depth of the bill 

 opposite the nostrils is hardly, or not. -§ of an inch, and thus 

 much less than half as long, instead of about half as long. 

 The gape is about 3 inches. While the bill shows the dilated 

 and denuded basal portion of the maxillary tomium, character- 

 istic of the species, this raised, naked border is uot yellowish, 

 but of a peculiar glaucous bluish-gray color. The tip of the 

 bill is less hooked than in true '■'■hrilnnichii,^^ though more so 

 than in troile. The modification of the bill appears somewhat 

 singularly analogous to that which takes place in var. ealifor- 

 nica as compared with true iro'ile. 



This bird is, of course, the true arra of Pallas, (a name ap- 

 parently derived from the Eussian vernacular,) whatever be its 

 relationship to the Atlantic bird. We should not be surprised 

 if some of the circumpolar forms were to connect the extremes 

 of hrilnnichii and iroile by insensible gradations. 



"The great egg-bird of the North Pacific, frequenting these 

 islands by millions. This Uria aud one other, the var. califor- 

 nica, are the only birds of the genus found here, but the latter 

 is in comparatively no number whatever, not one being seen 

 where a thousand of the former are visible at once. 



" They appear very early in the season, but do not begin to 

 lay until the 18th or 25th of June, and the natives tell me that 

 in open, mild winters these birds are seen in straggling flocks 

 all around the islands. I feel quite well assured that all the 

 individuals do not migrate from this sea and the vicinitv of the 

 Aleutian Islands. 



" They lay their eggs upon the points and narrow .shelves on 

 the faces of the cliff- fronts to the islands, standing over the 

 eggs, side by side, as thickly as they can crowd, making no 

 nests. They quarrel desperately, aud so earnestly, that all along 

 under the high bluffs on the north shore of Saint George's hun- 

 dreds of dead birds are lying, having fallen and dashed them- 



