The Zoologist— December, 1870. 2399 



Bill of 3'oung, first winter: culmen TSO; rictus 2"25; gonys '90; 

 depth at base "45 ; width at base "25. 



This species is well known to vary to a certain degree in size, and 

 in the precise shape of the bill. The dimensions given above represent 

 very nearly the average of a large suite of specimens measured. In 

 colours, the variations, though considerable, are unimportant, con- 

 sisting in the difference in shade of the colours of the upper parts, and 

 the difference in precise outline of the dark and light colours about 

 the head and neck, in summer as well as in winter specimens. 

 Specimens just before the renewal of the feathers have the upper 

 parts distinctly barred or waved with gray, owing to the fading of the 

 tips of the old feathers ; and the wing and tail feathers light dull gray. 

 The difference in intensity of coloration depends chiefly upon season, 

 though individual peculiarities may be observed. Very high plumaged 

 birds have the upper parts almost uniform in hue. 



The synonymy of this species is very extensive, and somewhat 

 intricate, though it is possible to collate it with much accuracy and 

 certainty, provided more labour be bestowed than the importance of 

 the matter warrants, as seems to the writer to have been the case in 

 the present instance. In consequence of the peculiarly obvious nature 

 of the characters which distinguish the several closely allied species 

 from the present one, even the brief diagnoses of the most antiquated 

 authors may be recognized and identified, in the majority of instances. 

 But it is curious to note that the various names most in vogue for two 

 or three species of this genus have been so frequently interchanged, 

 and so variously applied, not only in a specific, but in a generic 

 sense, that they have really come at last to mean nothing more than 

 simply murre or guillemot. It is absolutely necessary to refer to a 

 writer's description, or his authorities quoted, before we can have any 

 idea to what species he alludes under any given name — certainly 

 a very discouraging state of affairs, and one not placing Ornithology 

 in a very creditable light. 



The present species is Linnaeus' troile of Fn. Suec. 1761, and 

 S. N. 1766, and is so regarded by most writers. It is the lomvia of 

 Briinnich, which name is usually adopted by those writers who date 

 Linnaeus' prerogative of priority at 1766. It is minor of Gmelin, who 

 to a description of this species adds the synonyms of two others. It 

 is not troile of Briinnich, nor lomvia of Linnsus. 



Lomvia ringvia (Briinn.), Brandt.— Habitat : American and Euro- 

 pean coasts and islands of the North Atlantic. On the American 



