Letters of Mr. J. Graham Kerr. 359 



plumage of dark chestnut-colour. Talking about the Grebes 

 reminds me of a most interesting Duck that I have been 

 observing here a good deal, the Blue-billed Duck (Erismatura 

 ferruginea) . This is a Duck in name, but it has undergone 

 variations in external structure and in habits to an extraor- 

 dinary extent along the line of the Grebes. What drew my 

 attention to it was the first individual I saw ; it was swim- 

 ming, or rather floating on the surface of a lagoon. I ap- 

 proached to get within shot ; got within forty yards of the 

 bird and fired. However, the Duck was too sharp for me. 

 The pellets struck the water harmlessly all over the place 

 where the Duck had been. He had dived on seeing the 

 flash, and did it so well that I had considerable difficulty at 

 first in getting a specimen. The Blue-bill is thus quite equal 

 to a Grebe in his powers of diving. In structure, too, his 

 wings are exfremely small and almost useless for flight ; his 

 legs are placed right at the posterior end of the body ; the plu- 

 mage of his breast even is as satiny as that of a Grebe. The 

 tail of the Blue-bill is another of its peculiarities. Tail-coverts 

 are entirely absent ; the rectrices are about a dozen in num- 

 ber, very flat and stiff. When the tail is spread these form 

 a somewhat shovel-shaped and perfectly flat expansion, pro- 

 jecting quite suddenly from the blunt Grebe-like posterior 

 end of the body. Frequently when swimming, especially 

 when swimming rapidly, this flat tail is carried spread hori- 

 zontally beneath the surface of the water. At other times, 

 however, and especially when several Ducks are calmly 

 sailing to and fro in the sunshine, the tail is carried folded 

 together and cocked vertically right up in the air. This 

 increases the bizarre appearance of these Ducks, especially 

 when they indulge their Grebe-like habit of compressing 

 their air-chambers, so as to gradually sink downwards in the 

 water. In this way they will often submerge themselves 

 until nothing is visible above the surface but a head and neck 

 at one end, and, some distance from it, the tail. This habit 

 is so characteristic that I thought of speaking of this Duck as 

 the "cock-tail" Duck, but I concluded that this would be 

 rather too alcoholic a name. The Blue-bill Duck suits it pretty 



