58 PROCEEDINGS OF THE ACADEMY OF 



The above described differences between the adult and young are very de- 

 cided, and might suggest a distinction of species, were not various means 

 between the extremes forthcoming. Beyond these variations in plumage the 

 species is very constant in characters, with the exception of the bill. This 

 differs a good deal as to its size and shape ; but nevertheless usually preserves 

 the specific characters which distinguish it from that of Wurmizusume. Thus 

 the difference in length between the bills of two perfectly mature examples, 

 absolutely identical in plumage, and in all other respects, save length of bill, 

 amounts to a tenth of an inch along the culmen. This difference being 

 unaccompanied by a corresponding difference in depth and width, gives a 

 readily appreciable difference in shape of the bill. 



The only species to which the present bears any special resemblance is 

 Wurmizusume. The comparative characters of the latter are dwelt upon at 

 length in the article immediately succeeding. 



It is barely possible that two distinct species may be confounded in the 

 synonymy adduced at the head of this article, and that the bird here described 

 is not the veritable Alca nntiqua, Gm., (" Antient auk" of Pennant.) In the 

 description of these authors the upper parts are said to be dusky or sooty 

 black, whereas, as will be seen by the description, the subject of the present 

 article has these parts clear plumbeous. But we have just seen that the young 

 of the present bird has the upper parts decidedly darker and duller than the 

 adult; in fact tending, especially upon the wings and lower back, to dusky. 

 The limits within which the species is known to vary in this respect are suffi- 

 ciently wide to allow its reference to the bird of Pennant, Latham and Gmelin ; 

 especially when it is remembered that the particular descriptive terms used by 

 these authors may not have been criticallj' correct. It seems unnecessary, and it 

 would be, perhaps, unjustifiable to attempt to discriminate the present species 

 from Alca aniigua, upon the grounds just mentioned. They had best be re- 

 garded as the same, at least until suites of specimens may determine the exis- 

 tence of two species, differing in the particulars above mentioned. No indica- 

 tions of a distinction of species can be found in the extensive series of speci- 

 mens at present contained in American collections. 



This species, in the condition here described as that of the adult, is the 

 Uriel senicula, Pallas; and should bear the name of Siftithl iborhamphus seniculus 

 in the event of its not proving the same as Alca antiqua, Gm. Mergulus 

 cirr/iocephahis, Vigors, [Arctica cirrhocephala, Gray,) is the same bird, in the 

 same condition of maturity. The species has no other synonyms of conse- 

 quence, except those resulting from its reference to several different genera. 



In breeding plumage it is a very handsome bird, being in fact — with the ex- 

 ception of Wurmizusume — the handsomest of the Urinse. It is of frequent 

 occurrence along the coast and among the islands of the North Pacific ; extend- 

 ing, on the Asiatic side, to Japan, and on the American, to Washington Terri- 

 tory, U. S. It apparently migrates southward in winter. It breeds in the 

 vicinity of Sitka, R. A. It is well represented bj^ numerous specimens in the 

 collections of the Philadelphia Academy and of the Smithsonian Institution. 

 It has been figured by Temminck and Schlegel, and by Audubon. 



Synthliborhamphus Wurmizdsume, (Temm.) Coues. 



Uria Wurmizusume, Temminck, PI. Color, No. 579. Temminck and Schlegel, 



Fn. Japon, 1845. pi. 79. 

 Anobaptoii {Si/n/hliborhamphus) Wurmizusume, Bonaparte, Tab. Comp. Pelag. 



Comptes Rendus, 1856, xlii, p. 774. 

 Brachyrhamphus [Synthliborlunnphus) Temminckii, Brandt, Bull. Acad. St. Pe- 



tersb. ii, 18:^7, p. 347. Cassin, Baird's B. N. A. 1858, p. 916. 

 Brachyrharnphus Temminckii, Gray, Gen. Birds, iii, 1849, p. 644. Cooper and 



Suckley, Pac. Rr. Rep. xii. p. ii, 1860, p. 287. Elliot, B. N. Am. part vi, 1867. 

 Alca Temminckii, Schlegel, Urinat. Mus. Pays-Bas. livr. ix, 1867, p. 22. (Jajian.) 



[Jan. 



