424 Natatores. BIRDS. Colymbid^. 
the water, swimming and diving with astonisliing ease 
and rapidity in pursuit of the fishes and other animals 
which constitute their food. 
The Goosander, wliich is one of the largest species 
of this peculiar form, is a common bird iu the northern 
Fir. 133 . 
Head of Goosander. 
regions of both hemispheres ; in this country it is 
usually seen only in the winter, although some indivi- 
duals remain to breed in the northern parts of Scot- 
land. It frequents indifferently the fresh and salt 
waters, but in severe winters is usually driven to take 
tip its abode in deep bays, where its great power of 
diving enables it to procure a supply of food. 
THE RED-BREASTED MERGANSER {Mergus scr- 
rator) is another species which may be regarded as, 
to a certain extent, permanently resident in Britain, 
although chiefly a winter visitor ; and the Hooded 
Meiiganser (Af. mcullatus), distinguished by its 
broad crest, with a large white patch on each side of 
it, is a native of North America, of which, however, 
specimens have found their way to our shores. 
Family II.— COLYMBIDHU. 
The birds known as Divers and Grebes, which con- 
stitute this family, are readily distingvdshed from those 
just described, by the absence of the lamellae along the 
edges of the bill, which is rather elongated, of a coni- 
cal form, and acutely pointed. The nostrils are small 
and very narrow, forming mere slits in the sides of the 
upper mandible ; the wings are short, and the legs are 
jdaced so far back, and attached to the body in such a 
manner, that the birds are compelled to sit upright, rest- 
ing upon the whole length of the tarsus when on dry 
ground. The feet are large, and the toes sometimes 
fully webbed, sometimes bordered by ample but dis- 
tinct membranes; the posterior toe is always present, 
although small. 
These birds, which are essentially aquatic in their 
habits, never venturing to move far from the water’s 
edge, are found principally in the northern hemisphere. 
Some of them frequent fresh waters, others prefer the 
sea-coast ; they fly with considerable rapidity, but only 
for short distances. They swim and dive with the 
greatest ease, and progress under water with the most 
astonishing rapidity, their movements when submerged 
being greatly’’ aided by the action of the wings. Their 
food consists of fishes, mollusca, insects, and Crustacea. 
THE GREAT NORTHERN DIVER (Colymbus glad- 
alis), the largest species of this group, measuring 
nearly three feet in length, is met with chiefly in 
the arctic regions of both hemispheres, but advances 
further south at the approach of winter, when it 
occurs in great abundance about the shores of the 
[ northern parts of Scotland. At this period it lives 
j principally on the sea, capturing herrings, sprats, and 
other small flsh by diving ; but in the summer these 
birds frequent the numerous fresh-water lakes of the 
extreme north, on the margins of which they make 
their large flat nests of dry herbage. On land the 
Diver is very awkward, as it is compelled to rest upon 
its lower surface, and push itself on with its feet ; but in 
the water it moves with surprising rapidity, its speed 
equalling that of a four-oared boat ; and even under 
water it moves with undiminished swiftness, coming 
up at intervals for the sake of air, but often remaining 
below the surface for six or seven minutes at a time. 
Two other species, the Black-thrgated Diver 
{C. arcticus) and the Red-throated Diver {C. sep- 
tentrionalif)), which correspond with the Great Northern 
Diver in their distribution and habits, are sufficiently 
distinguished by the peculiarities indicated in their 
names. They are both met with on the British coasts, 
the latter abundantly, the former more rarely. 
THE GREAT CRESTED GREBE {Pocliceps cristatus). 
— The Grebes are distinguished from the Divers by the 
peculiar structure of their feet, in which the mem- 
branes, instead of uniting the toes, are cleft nearly to 
the base of the latter, forming bi'oad membranous 
margins. In other resjiects, the two forms are very 
similar, as also in their habits, although the Grebes 
frequent lakes and other pieces of fresh water in pre- 
ference to the sea. The Great Crested Grebe, one 
of the largest species, measures from twenty-one to 
twenty-two inches in length, and has the plumage of 
the upper surface dark brown, and that of the lower 
parts white ; the wings exhibit a white patch formed 
by the secondary quills ; the top of the liead is dark 
brown, and is adorned at the back with a double crest 
of the same colour; the cheeks are white, and below 
the head there is a sort of tippet, hanging down all 
round the neck, of a pale chestnut colour, deep chest- 
nut at the lower margin. 
This bird is an inhabitant of most of the northern 
parts of both hemispheres. In this country it is a 
constant resident, frequenting the lakes and other 
extensive pieces of water. It feeds upon aquatic 
animals of all kinds, which its great natatorial powers 
enable it to capture with case. 
THE HORNED GREBE {Podiceps cormitus), also 
known as the Sclavonian Grebe, is a much smaller 
species than the preceding one, which it resembles in 
its general habits and distribution, but is a rare bird 
in this country in summer. The male is distingui.died 
