BLACK-AND-WHITE BIRDS. 37 



and Puffiii, the Manx Shearwater is not bound to a 

 laborious, dead-ahead flight, but scours the waves 

 with the splendid freedom of all the Petrels. The 

 ' sheafing ' consists of an alternate rising and falling 

 as the bird flies, never far above the surface of the 

 water. Scouring the waves, to the shifting contour 

 of which it adapts its flight, it rises, and, canting, 

 cuts down sidewards on outspread wings ; then, after 

 skimming the waves again, it rises once more, and 

 in a similar manner cuts down to the surface in 

 the opposite direction. The dark upper and the 

 white under parts thus come into view with some 

 regularity of alternation. The bird is oceanic in 

 its habits, and may be met many miles from land. 

 As a breeder it resembles the Puffin, making a deep 

 burrow in the soft earth at the cliff-head in which 

 to deposit its one egg. During the breeding season 

 it flies by night, its plaintive ' Kookoo-kooroo ! ' 

 sounding now here, now there, as the bird wanders 

 over the dark waters. 



COMMON GUILLEMOT— 18 inches; upper parts dark 

 brown ; wing-bar and under parts white ; bill with 

 plain, undeflected point ; legs and feet olive. 



RAZORBILL — 17 inches; black above; wing -bar and 

 under parts white ; massive bill, shaped like a razor- 

 head. 



PUFFIN — 13 inches ; thick-set ; white owlish face; massive 

 tri-coloured bill ; legs and feet bright red. 



STORM-PETREL.— Plate 19. 6| inches. Black 

 throughout, except a patch of solid white on the 

 upper surface from the rump inclusive to the root 

 of the tail ; bill, legs, and feet also black, the bill 



