258 
COLYMBUS GLACIALIS. 
a few stripes of the same ; the whole of the upper parts 
are of a deep black, slightly glossed with green, and 
thickly spotted with white, in regular transverse or 
semicircular rows, two spots on the end of each feather, 
— those on the upper part of the back, shoulders, rump, 
and tail-coverts, small and roundish, those on the centre 
of the back, square and larger ; those on the scapulars 
are the largest, and of an oblong square shape ; the wing- 
feathers and tail are plain brown black, the latter 
composed of twenty feathers ; the lower parts are pure 
white, a slight dusky line across the vent ; the scapulars 
descend over the wing when closed, and the belly 
feathers ascend so as to meet them, by which means 
every part of the wing is concealed, except towards the 
tip ; the outside of the legs and feet is black, inside lead 
colour ; the leg is four inches in length, and the foot 
measures, along the exterior toe to the tip of its claw, 
four inches and three quarters ; both legs and feet are 
marked with five-sided polygons; weight of the specimen 
described, eight pounds and a half. 
The female diver is somewhat less than the male ; 
the bill is yellowish ; crown, back part of the neck, and 
whole upper parts, pale brown ; the plumage of part of 
the back and scapulars is tipt with pale ash ; the 
throat, lower side of the neck, and whole under parts, 
are white, but not so pure as that of the male, having a 
yellowish tinge ; the quill feathers dark brown. She 
has no appearance of bands on her neck, or of spots on 
her body. 
The young males do not obtain their perfect plumage 
until the second, or third year. One which we saw, 
and which was conjectured to be a yearling, had 
some resemblance to the female, with the exception of 
its upper parts being of a darker and purer brown or 
mouse colour, and its under parts of a more delicate 
white ; it had likewise a few spots on the back and 
scapulars ; but none of those markings on the neck 
which distinguish the full grown male. 
The conformation of the ribs and bones of this species 
is remarkable, and merits particular examination. 
