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 gi'oup'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 (Hydromis), which has been 

 tentatively assigned to this order. 



The Albatrosses. 

 Family DlOMEDEID^. 



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 homy 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 (juills in the wing, which may vary from thirty-nine 

 to lifty, or more than in any other birda 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 Dioi'iiedea) 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 noteworthj'. 



By far the best known representative of the genus is the wandering albatross 

 (Z). exidans), which is the one represented in our illustration. It belongs to a group 

 characterised by the absence of a gi'oove in the homy 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 lbs. 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. fioliginosa), 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 



