PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 211 



ber of Okeu's Isis, 1824 (pp. 877-891), Mr. Benicken described a new 

 Guillemot in the following words) : 



[p. 888J Uria. 

 " Altliough convinced that great discretion is to be exercised in estab- 

 lishing new species, particularly among the northern water birds, in 

 which the different species of each genus are so very much alike in 

 regard to coloration, while even the different individuals of the same 

 species, according to circumstances, vary greatly in size and shapeof bill, 

 etc., I am inclined to think that, besides the known species of Uria, still 

 a new one occurs in the polar seas, which, although on the whole resem- 

 bling the allied forms, differs distinctly from every one of them. The 

 length of the bird is 16 inches 9 lines, Hamburg measure [=400 "'"^*]. 

 Bill black, much compressed, with very i^rominent edges of the upper 

 mandible, a strongly -marked gonydeal protuberance, bent tip, and 

 feathered as far as above the nostrils. 



"Length of bill from forehead 1 inch, l) lines H. m. [42'"'°] 



_ _ from angle of mouth 2 — 3 — [54*^™] 



_ _ from nostrils 1 — [24'"'°] 



Length of head, from nape to forehead 2 — [48^"™] 



Length of head including the bill 3 — 9 — [90'»m] 



"Tarsus 1 inch 6 lines [36 ™™], yellowish brown. The webs whitish. 

 The entire plumage sooty black, on the abdomen shading somewhat into 

 grayish ; wingfeathers brownish black. 



" From this description it is jilain that the bird in question is distin- 

 guished from U, grylle by being of larger size, from U. troile and Briin- 

 nichii by having a differently shaped bill. The latter is much shorter 

 and more compressed than in U. troile, in shape resembling more that 

 of U. Brihtnichii, but is shorter and only one-third as broad. 



" I am unable to say more about this bird, as I only received one sin- 

 gle skin in 1820. Mr. Faber, who in Iceland had ample opportunities 

 for studying the known Guillemots, declares it to be a new species. 

 Should other ornithologists agree herein and allow me, as the first de- 

 scriber of the species, to apply a name to it [p. 889)] I should wish to 

 have it named Uria Motzfeldi, after a friend of mine to whom I am in- 

 debted for many a northern curiosity." 



In the following, the September, number of the same journal, Faber, 

 in the third part of his excellent "Beytriige zur arctischen Zoologie" 

 (Contributions to Arctic Zoology), treating monographically of the genus 

 Uria { = Cex>phiis -f Uria), on page 981, describes the same specimen 

 as new under the name of 

 [p. 981] "~- C'na unicolor. 



" By this name 1 wish to call theattention of ornithologists to a very 

 rare Guillemot found in the northern bird-rookeries. I will here present 

 my data, leaving it to later experience to decide whether it is a new 

 species or not. The owner of the bird-rookery on Draugoe- [Iceland], 



* One inch Hamburg measure = 0.0239"". 



