212 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



■who knew very well the birds breeding on the rookery, told nie, as a 

 great curiosity, that sometimes a pair of bhick-birds {uria troile) were 

 breeding on the rocks, which were reddish- brown all over; they were 

 described to me as being as large as the young aica torcla, but of the 

 habits of uria Brilnnichii. This was rather remarkable. I did not pay 

 much attention to it, however, before last fall, when, in the collection of 

 Mr. Secretary Benicken, in Sleswick, I was struck at the sight of au 

 uria which he had received from Greenland, and which agreed closely 

 with those described above. It was uniform reddish-brown all over the 

 body, with darker bill and feet, and of the size. of a young alca torda. 

 The bill, differing from that of all known Guillemots, had shape and 

 size intermediate between that of uria BrUnnichii and uria grylle. It 

 sometimes happens that albinistic varieties are found among the 

 northern birds; thus I know of white varieties of tiria grylle, uria alle 

 carbo graculus, anas hisirionica, but I never happened to observe the 

 pure Avhite color varying into the darker, as would here be the case, as 

 the uria presently named can by no means be regarded as a variety of 

 any other species than uria Briinnicliii, which always has the breast 

 and belh' white. The bill and the whole body, however, are too small 

 for an old uria BrUnnichii ; but this uniformily colored uria must be 

 old, as it is said to have bred on the rookery at Drangoe. It may 

 [p. 982] also be remarked that Fabricius (in the faun. Groenl. p. 81, No, 

 3) mentions an uria dorm riihro, for the rest similar to uria BrUnnichii,. 

 and Strom, in his description of Sundmor [I, p. 219), speaks of an alca 

 pectore ruhroJ^ 



This is the original description of Uria unicolor. It will be seen that 

 U. motzfeldi has the priority over Faber's name by one month, conse- 

 quently the one to be adopted if the bird should turn out to be distinct. 



The next time the bird is mentioned is in the same journal for 182G, 

 where Brehm (on p. 988) speaks of " Uria unicolor Benicl-en^^ as being 

 " blackish brown," but too little known to him to be assigned its precise 

 position. 



Brehm, therefore, is the originator of the " [7na imcoZor Benicken," 

 a quotation afterwards to be found in most cases when the bird has been 

 mentioned. 



We have seen that Faber in 1824, in describing Uria unicolor, regarded 

 it as mostly allied to U. briinnich ii. He seems afterwards to have changed 

 his opinion, however, fo? in the continuation of his elaborate monograph 

 (Beytriige zur arctischeu Zoologie, VIII, Isis, 1827, ]). G39) he speaks 

 only of " Variat. extraord. avis tota alba vel tota nigra,''^ under the head- 

 ing of Uria grylle. U. unicolor is not mentioned at all, but it is almost 

 certain that this "variatio extraordinaria" "tota nigra" of grylle is the 

 same thing. 



Brehm, in his "Handbuch der Naturgeschichte aller Vogel Deutsch- 

 lands" (1831, p. 985), does not add anything to what he said in the 

 Isis for 182C. 



