xlii NATURAL HISTORY. 



36.— COLYMBUS GLACIALIS {Great Northern Diver). 



COLYMBUS GLACIALIS.— Rich -. Faun. Bor. Amer.— vol ii., p. 474. 



Temm. — vol. ii., p. 910. Fub : Faun. Green. — p. 97. 

 Sub ; Franklin's Journey — p. 703. 

 NORTHERN DIVER.— Penn .- Brit. ZooL— vol. ii., pp. 16.5, 167, pi. 30. Arct. Zoo/.— vol. ii , p. 518. 



Only three specimens of this magnificent bird were obtained, and in each of these a 

 most striking difference was observed in the colour of the bill, from the usual descrip- 

 tions of authors. In our specimens the bill being of a very light horn colour, whilst 

 in the European bird it is described as being black. There are other differences in 

 the relative measurements of our bird, which will be more manifest by comparing the 

 dimensions given by Dr. Richardson, loc. cit., with the mean of the measurements of 

 our three specimens^ 



36 inches. Mean of bur specimens 31.4 inches 



2.7 

 3.65 

 5.42 

 4.2 

 58 

 10 pounds. 



Thus it appears that our bird, though four inches and a half shorter, has a bill eight- 

 tenths of an inch longer, and ten inches greater extent of wing than that described by 

 Dr. Richardson. I should have been disposed to agree with Wilson in supposing that 

 there are two species, and have assigned to the Boothian Divers a new specific name' ; 

 but on communicating with my friend Joseph Sabine, Esq., whose ornithological e.xpe- 

 rience is only exceeded by the ready assistance he affords to whoever may wish 

 to avail themselves of his high authority, I am now induced to concur with him 

 in the belief that the lighter colour of the bill may be occasioned by age, more 

 especially as no ditlerence of any importance could be detected in the colours 

 of the plumage. 



