48 PROCEEDINGS OF THE ACADEMY OF 



ing, or very imperfectly developed; its place on the culmen being occupied 

 by a soft skinay covering like that on the nasal fosste. 



Specimens frequently occur in this condition. An understanding of its 

 precise import is somewhat complicated by the fAct that, although the tuber- 

 cle is entirely vranting, and the bill otherwise obviously undeveloped, the 

 head is well provided with the whitish setaceous feathers. Birds in such 

 condition might be confounded, on casual inspection, with 5. pitsillus. But 

 more careful examination will result in the observation, that the bill is far 

 too large, thick, and heavy to be that of pusillus ; that there is no conspicuous 

 white patch on the scapulars; that the size of the whole bird exceeds that of 

 pusillus; which points, in connection with some others which might be enu- 

 merated, will serve to distinguish the two species. Their relationships are 

 dwelt upon more at length in the succeeding article. 



When old birds of this species are moulting, in the fall, the glossy black 

 of the fresh feathers on the back is interrupted with dull grayish black 

 patches, formed by the old feathers which have not yet been renewed ; and 

 the old worn primaries and secondaries are dull grayish, fading almost into 

 grayish white at their tips and along their edges. A specimen in such a con- 

 dition, (No. 46,563, Smiths. Mus.) though palpably an old bird, has no trace 

 of a caruncle on the bill. 



It may not, perhaps, be exceeding due bounds, to hint at the possibility 

 that the nodule on the bill may be temporary in character, assumed after a 

 certain age, at a certain season, and then lost, wholly or in part, by absorp- 

 tion, to be again resumed at the same period of the following year, probably 

 during the season of reproduction. This suggestion presents itself to the 

 observer without straining on his part, and, in fact, is rather forced upon his 

 attention, after examination of specimens, apparently adult, in which no 

 trace of the tubercle is to be found. The tubercle is in essential character- 

 istics an extrinsic formation upon the bill, differing radically in its structure 

 from the rest of the organ. No good reason appears to forbid the supposi- 

 tion that its growth and subsequent re-absorption, maybe periodical. Argu- 

 ments for such a belief might readily be adduced in the periodical hyper- 

 trophy and atrophy of the combs, wattles, caruncles, and the various other 

 fleshy or cutaneous or semi-corneous growths about the head and bill of very 

 many birds, which enlarge during the breeding season, and afterwards 

 diminish or entirely disappear. It is also within the limits of possibility 

 that caruncles of this species is a sexual characteristic. The specimen above 

 mentioned, (No. 46,563,) is marked female. However close to, or remote 

 from, the truth either or both of the foregoing suggestions may be, it is cer- 

 tain that observed facts relating to the rostral knob of this bird are at vari- 

 ance with generally received doctrines about it, and are explicable by the ap- 

 |)lication of one or the other of the preceding hypotheses. At present we are 

 very much in the dark in the matter. 



Various ages, conditions of plumage and bill, of this species are well 

 represented by the numerous specimens in the Museum of the Philadelphia 

 Academy and of the Smithsonian Institution, from various localities along 

 the coasts and among the islands of the North Pacific. No specimens are 

 contained in any other American collection. 



The only questions of synonymy which arise in this case are connected 

 with the identification of Alca pygmoca, Gm., and are treated of under head 

 of S. pusillus. Prof. Brandt's name has priority over that of the Prince Bona- 

 parte, although the latter has come into more general employ than the former, 



SiMORHYNCHtJS PUSiLLtTs, {Pallas) Coues. 



1 Alca pj/f/mxa, Gmelin. S. N. i, pt. ii, 1788, p. 555, No. 12 ; " rostro nigro, 

 Venice, cervice, dorso, alls, cauda pedibusque obscuris, jugulo et pectore 

 glaucis, abdomine sordide albo. * * alee minor, 7 poll, longa," 



etc.— Based upon Pigmy Auk, Pennant, Arct. Zool. ii, p> 513, No. 431. 



£Jan. 



