87 
of the neck, and the under parts of a pure 
white ; feathers of the back, wings, rump, 
and sides, of a very deep brown in the mid- 
dle, bordered and terminated by bluish ash 
colour; upper mandible ash-coloured grey, 
lower whitish ; irides brown ; legs exter- 
nally of a deep brown, internally as well as 
the webs whitish. In this state of plumage 
it is the Colymbus Jmmer of Gmelin and 
Latham, and the Imber of authors. At the 
age of one year, the individuals of both 
sexes assume about the middle of the neck 
a transverse band of dusky brown, about 
an inch in length, and which forms a kind 
of collar ; the feathers of the back have a 
dusky tint, and the small white spots begin 
to appear. At two years of age the collar 
is more fully formed; this part, the head, 
and neck, are variegated with brown and 
greenish black feathers; the numerous spots 
upon the back and wings appear, and the 
band under the throat as well as the collar 
on the back of the neck is marked out by 
brown and white longitudinal streaks. At 
the age of three years the plumage is com- 
plete. 
