154 BRITISH SEA BIRDS. 
not yet agreed upon the degree of their relation- 
ship. United, these three families form Dr. 
Sclater’s order Pycoroprs. In every way the 
Divers are remarkably well fitted for an aquatic 
life. Their strong tarsi are laterally compressed, a 
form best suited for cleaving the water, the hind 
toe is well developed, and on the same plane as the 
rest, the feet are webbed, the bill is long, straight, 
spear-shaped and conical, admirably adapted for 
seizing the finny prey, the wings are comparatively 
short, yet capable of bearing the bird at great 
speed, the tail is short and fairly developed. The 
Divers in nuptial plumage are remarkably hand- 
some birds, the neck being striped or richly marked, 
and the upper plumage beautifully spotted or 
adorned with white bars. They are all more or 
less gregarious birds during winter, and well 
marked social tendencies are displayed in some 
species during the breeding season. Their mi- 
grations, if comparatively short, are pronounced 
and regular. The young are hatched covered 
with down, able to swim with ease almost imme- 
diately. Adults moult in autumn, and assume their 
nuptial plumage in winter—a period doubtless 
when they pair—the winter plumage thus being 
carried for a short time. Young Divers carry their 
first plumage through the winter until the following 
spring (not moulting in December with their 
parents), when they assume their summer plumage, 
but the nuptial ornaments are not so brilliant in 
