2*26 BILLS OF. DIVING BIRDS. 



are not formed for following it like the divers. They 

 therefore require to have the bill of a more prehen- 

 sile form than the one, and better able to retain its 

 hold than the other. Accordingly, they have the 

 bill lengthened, firm in its texture, nearly cylindrical, 

 hooked at the tips of both mandibles, and serrated 

 with reflected teeth along the cutting edges. They 

 live upon fish and reptiles, and their flesh is rather 

 rank in flavour. The preceding is a sketch of the 

 bill of the red-breasted merganser. 



The divers and guillemots drive through the water 

 with great rapidity, and transfix their prey with the 

 sharp points of the mandibles, or wound it with the 

 snap of the tomia, which in some of the species are 

 furnished with a notch. This notch, which is of a 

 very peculiar form, quite different from that in the 

 bills of the rapacious or the insectivorous birds, is well 

 shown in the bill of the foolish guillemot (Uria Iroi/e,] 

 of which a figure is annexed. 



In proportion as those birds which are dependent 

 on the sea for their subsistence, and capable of fol- 

 lowing their prey to some distance under water, 

 become less capable of motion on land or on tin- 

 wing, their bills increase in power. We have exam- 



