440 BIRDS OF AUSTRALIA. 



wings, it compels him to drop it, and then seizes it before it 

 sinks again. This bird, which is called ' Molly Hawk ' by 

 the sailors, is common round Cape Agulhas ; and, in August 

 1857, I saw a large number in False Bay and round Cape 

 Hanglip. It is apparently quite diurnal in its habits, both 

 at sea and near land." — I6is, 1865, p. 283. 



But little difference is observable in the plumage of the 

 sexes, neither is there any visible variation in this respect 

 between youth and maturity ; a never-failing mark, however, 

 exists by which the latter state may be distinguished: the young 

 bird has the bill dark brown, while in the adult that organ is 

 of a bright bufFy yellow ; and individuals in the same flight 

 may frequently be seen in which the bill varies from dark 

 horn-brown to the most delicate yellow. 



I did not discover the breeding-place of this species. 

 " Commander Snow, in his ' Two Years' Cruise off Terra del 

 Fuego,' says it breeds on the Falkland Islands, and describes 

 its nest as similar to that of Diomedea exulans, but not more 

 than twelve inches high ; and Captain Carmichael states tliat 

 it breeds on Tristan d'Acunha." — Idis, 1865, p. 283. 



Head, back of the neck, all the under surface, and the upper 

 tail-coverts pure white ; before, above, and behind the eye a 

 streak of blackish grey ; wings dark brown ; centre of the 

 back slaty black, into which the white of the back of the neck 

 gradually passes ; tail dark grey, with white shafts ; bill buffy 

 yellow, with a narrow line of black round the base ; legs and 

 toes yellowish white, the interdigital membrane and the joints 

 washed with pale blue; irides very light brown, freckled with 

 a darker tint. 



