64 BIRD GALLERY. 



Torrent-Duck {M. armatd) (688)^ frequents the high mountain torrents 

 of tlie Andes, and forms a link between the true Mergansers and the 

 stiff-tailed Diving-Ducks, but diflFers from the former in having no teeth 

 on the edges of the mandibles and in having the bend of the wing armed 

 with a strong spur. The New Zealand Soft-billed Duck {HijmenolcBmiis 

 malacorhynchus) (689) is worthy of special notice on account of its 

 remarkable bill with a dependent membrane, suited for the capture of 

 insect larvae on Avhich it principally feeds. 



[Case 37.] The Stiff-tailed Ducks, so-called from their rather long, narrow, rigid 

 tail-feathers which are often carried erect when the bird is swimming, 

 include several genera of which representatives will be found in the 

 White-headed and Australian species of Erismatura (690, 691), 

 the American Masked form {Nomonyx) (693), and the Musk-Duck 

 {Biziura lobata) (692). The latter, whose name is derived from the 

 strong musky odour of the sitting female, frequents the seas as well as 

 the lakes of Australia and Tasmania. It is much the largest species of 

 the group, and remarkable on account of the leathery chin-pouch found 

 in both sexes. The appendage opens under the tongue and is largest 

 in the male, giving the bird a very peculiar appearance. Like its 

 allies it is an expert diver and can remain for a long time submerged. 

 It seldom, if ever, flies in the daytime, but will do so at night. The 

 nest is placed in aswanip or in a bank, and contains two or three olive- 

 coloured eggs. 



Of Sea-Ducks we may first mention the Eiders, which are all in- 

 habitants of northern waters, and are represented by S teller's Eider 

 [Heniconetta stelleri) (694) and the King- and Common Eiders {Somateria 

 spectabilis (695) and S. mollissima (696)), all of which are included in 

 the British List. Their nests supply the " Eider down " which forms an 

 important article of export in countries such as Norway, where the 

 common species is protected by law and consequently exceedingly 

 numerous. It will be noted that the series exhibited shows the 



[Case 37 1 changes from summer- to winter-plumage in both the old and young 

 drakes, the " eclipse " or intermediate autumn-plumage being specially 

 interesting. 



[Case 38.] The South-American Rosy-billed Duck {Metopiana) (697) is often 

 kept on ornamental waters in this country. The Pochards {Netta 

 and Nyroca) include the Red-crested (698) and Ferruginous (701) 

 species, both of which occur in Great Britain as occasional stragglers, as 

 well as the Common Pochard (699) and the Canvas-Back (700) from 

 North America, famous for its excellent qualities as a bird for the table. 

 The Tufted Duck [Fuligula) (703) breeds plentifully on the lochs and 

 ponds of Great Britain and Ireland, and is easily recognised by the 

 long drooping occipital crest developed in both sexes ; the Scaup 



