520 TUBE-NOSED BIRDS. 
divers. In appearance several of them, more especially the fulmars, present a 
marked similarity to the gulls; the plumage in this instance being of the grey- 
and-white hue distinctive of that group. This resemblance must, however, be 
regarded as a purely adaptive one, brought about by the needs of a similar mode 
of existence, there being but little structural affinity between the members of 
the two groups. Generally, the tube-nosed birds have a more or less dusky-hued 
plumage, while they mostly differ from the chattering and screaming gulls by 
their comparatively silent habits. Although found in the seas of all parts of 
the world, the group is represented by the greatest number of species in the 
Southern Hemisphere, which may consequently be regarded as its headquarters. 
Very little is known of the group’s geological history, although a species of 
shearwater has been stated to occur in the lower Miocene strata of France; the 
same beds also yielding remains of an extinct genus (Hydrornis), which has been 
tentatively assigned to this order. 
THE ALBATROSSES. 
Family DIOMEDEID2. 
The albatrosses are distinguished by their tubular nostrils being placed on the 
two sides of the beak, and widely separated from one another by the large median 
portion of its horny sheath. They are further characterised by the extreme length 
and narrowness of the wing, in which the humerus and ulna are greatly elongated ; 
and also by the large number of quills in the wing, which may vary from thirty-nine 
to fifty, or more than in any other birds. In the foot the first toe is wanting ; while 
the skull is characterised by the absence of basipterygoid processes on the rostrum 
of its inferior surface. All the albatrosses (which may be included in the single 
genus Diomedea) are of large size, and mainly frequent the southern tropical and 
subtropical seas, although one species ranges on the Pacific Coast of America as 
far north as Alaska. The occurrence of remains of a fossil albatross in the 
Pliocene deposits of the east coast of England is noteworthy. 
By far the best known representative of the genus is the wandering albatross 
(D. exulans), which is the one represented in our illustration. It belongs to a group 
characterised by the absence of a groove in the horny sheath of the sides of the 
lower jaw, and also by the length of the wing being equal to three or four times 
that of the short and rounded tail. The span of wing varies from 10 to 12 feet, 
while the average weight of the bird is only some 17 Ibs. The prevailing colour of 
the plumage is yellowish white, with the quills dusky, and, except in very old 
birds, the region of the back and the larger wing-coverts are irregularly barred 
with blackish. The beak and feet are whitish. Although the true home of this 
species is in the south seas, its wanderings occasionally extend to the north of the 
Equator. The smaller sooty albatross (D. fuliginosa), of the southern oceans 
generally, and the Pacific, alone represents a second section of the genus, in which 
the horny sheath of the sides of the lower jaw is marked by a longitudinal groove, 
while the wing is only about twice the length of the graduated tail. In the adult 
the plumage of the neck, back, and upper- parts is dark ashy grey, becoming 
lighter on the neck and fore-part of the back, where the tips of the feathers are 
