No. V.] 



ZOOLOGY. 



70S 



Colymbus Glacialis. , Great Northern Diver. 



This bird has been long well known, except that in its immature state it has been 

 called Colymbus Immer, and the Immer Diver. It is found in the northern coun- 

 tries of both worlds, breeding and living on the sides of lakes, and going southwards 

 in severe weather, where it is equally oberved on the sea, and in fresh waters. These 

 birds differ much from each other in size, which has led Wilson to conjecture that there 

 may be two species, the smaller belonging to America; but this cannot be the case, 

 since specimens have been received from Canada, as large as any killed in Europe. 



Colymbus Septentrionalis. Red-throated Diver. 



This- species, though spread over the whole Arctic Regions, is particularly abun- 

 dant in Hudson's Bay, and in the lakes in the interior. It is a more northern 

 bird than the Northern Driver, is found nearer to the Pole, and goes less to the 

 south. The young, are much more plentiful in the temperate counties in the winter 

 than the old birds* It is subject to great variety in size, the length being sometimes 

 twenty-one inches; in other cases, twenty-eight inches. The young have been called 

 Colymbus Stellatus, Striatus, and Borealis ; Speckled Diver and Striped Diver. Buffon 

 mistook it for the female of the Black4hroated Diver ; and did not , therefore, make 

 it distinct. It is not noticed by Wilson in his American Ornithology. 



