BILLS OF LONG-TOED BIRDS. 223 



in their haunts and many of their characters, but 

 they live on mollusca and reptiles rather than on 

 fish ; the pratincoles, which subsist chiefly upon 

 insects which they capture on the wing ; and they in 



some of their habits resemble the bee-eaters, and 

 the carrion bird of Australia, Chionis necrophaga, 

 which has no type among European birds. 



BILLS OF AQUATIC BIRDS. 



The bills of which some account has been given, 

 bring us to the margin of the water, and we have 

 only to notice the birds which find their food in that 

 element. The general characters of these depend 

 less upon the bill than those of the land birds, but 

 there are two well marked divisions : those which 

 find their food at the bottom of shallow waters, and 

 those which feed chiefly upon what is buoyant in the 

 clear water, though the first eat floating substances 

 when they come in their way. 



The first comprises the geese, swans, and ducks, 

 which are all really ground feeders, only some of 

 them feed almost exclusively on ground covered with 

 water, and their bill and neck vary according to the 

 depth of water with which their feeding ground is 



