AVES NATATORES. 
89 
Deutsclilands,” has been published. The concluding half of 
the former, and commencement of the present volume, are 
occupied with the genus Anas. 
The anatomical characteristics of the genus have been arranged, with 
valuable annotations, by Rud. Wagner, from the papers left by Nitzsch. 
The following species have been treated of in the following order : — 
First Group, Swimming Ducks, with an unlobed hinder toe. — a. Bur- 
rowing Ducks, called by later Ornithologists, Tadorna or Vulpanser, 
although they have nothing of the Goose tribe. 1. A. tadorna: 2. A. 
rutila. h. Fresh-water Ducks, “ lately divided into five genera and 
more, on account of slight deviations, which are scarcely tenable, as 
sub-genera.” 3. A. hoschas : 4. A. acuta: 5. A. strepera: 6. A. quer- 
quedula: 7-A.crecca: 8. A. penelope. c. Shovellers. 9. A. clypeata. 
Second Group, Divers, with the hinder toe lobed. “ This great section 
may be properly divided into several sub-divisions or families, between 
which there is no want of transitions, on which account it is difficult to 
determine whether the whole group should be considered as a separate 
section of the genus Anas, or whether our following families of Ducks 
should appear as so many different genera.” a. Fen Ducks. 10. A. ru- 
jina: ll.A.ferina: 12. A. nyroca (leucophthalmos) : 13. A. fuligula: 
11. A. marila. 
Anas purpureoviridis, Scliinz, lias been pronounced by Selys 
and Bonaparte a hybrid of Anas hoschas and A. moschata. 
Selys relates, in the Faune Beige, p. 141, that he shot a female of 
A. pwrp. at Longchamps-sur-Geer, in December 1835. He saw a male 
at Baillon ; and examined two other males in the museum at Lausanne, 
perfectly alike, which had been killed on the Lake of Geneva. 
Leib found the nest of Anas discors, along with that of A. hoschas, in 
the meadows which border on the marshes of Lake Erie. It was com- 
posed of dry grass, thickly lined with feathers, and contained eighteen 
eggs of a delicate cream colour. (Journ. of Philad. 1842, p. 204.) 
Gould has formed a new genus, Merganetta, for a species 
of Duck from the the Chilian Andes. (Ann. ix. p. 511.) 
In many of its characters, as he says, it approaches the Ducks, but in 
others it evinces an afiinity with the Mergansers, especially in its long 
and stiff tail-feathers and narrow and pointed beak. It differs, how- 
ever, from either of the groups mentioned, in having, in both sexes, 
a strong spur on the wing. Gould gives to the species the name 
M. armata. 
Gould has figured a new species of Duck in the Birds of Australia, 
part 6 , Nettapus coromandelianus, Gm., and pvichellus, G, 
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