ERISMATURA.—MERGANSER. 929 
(Grayson ®), Aguas Calientes (Richardson 1), Guanajuato (Dugés*), Valley of 
Mexico (Herrera®, Le Strange'’), Laguna de Chapulco, Puebla, Jalapa, Vera 
Cruz (Ferrari-Perez"), Oaxaca (Boucard *); Guatemata, Duefias, Lake of Atitlan 
(O. S.3 418); Cogra Rica, Irazu (v. Frantzius !2)—Conomsra 11; West Inpiss !! 2, 
The Ruddy Duck inhabits the greater portion of North America, and is found 
breeding throughout the temperate area of that Continent, as well as in Central 
America. The species also occurs in Colombia, and is believed to breed there. In 
Mexico, according to Herrera, the native name is ‘* Yacatexoctli.” We met with the 
bird in Guatemala °, breeding on the Lake of Duefias, where it was the only resident 
species of the Anatide. 
Salvin * writes :—* It is more easily procured than any of the other Ducks frequenting 
the Lake, as its powers of flight render its escape less easy. Not but that it flies as 
well as any other when once fairly started; but it finds difficulty in rising from off 
the water, so much so, that, by sailing down-wind towards a bird, it usually admits of 
approach to within easy shooting-distance. Sometimes, however, it seeks safety by 
diving; and when such is the case, its powers in this respect are so great that escape 
is almost certain to ensue. It builds in May, amongst the reeds on the margin of 
the Lake, making a nest of the dead flag with a little down.” The eggs are rough 
in texture, of a dirty creamy-white colour. 
Subfam. WERGINAL. 
The Mergansers, which are the representatives of this subfamily, are northern birds 
which reach Central America only in winter. They differ from the other Diving-Ducks 
noticed here in their narrower and more compressed bills, which are remarkable for 
the tooth-like serrations along the edges of the mandibles. 
MERGANSER. 
Merganser, Briss. Orn. vi. p. 230 (1760) ; Salvad. Cat. Birds Brit. Mus. xxvii. p. 471 (1895). 
The true Mergansers may be distinguished from Lophodytes by the conspicuous 
tooth-like serrations of both mandibles. ‘The genus is a cosmopolitan one, and 
though represented by seven species—three of which have a northern habitat— 
resident forms are found within the tropics, of which VW. drasilianus is an example. 
One species only, J. americanus, visits Central America in winter. 
1. Merganser americanus. 
Mergus americanus, Cass. Pr. Acad. Philad. 1853, p. 1871; Allen, Bull. Amer. Mus. N. H. y. 
p. 827; A.O. U. Check-l. N. Amer. Birds, 2nd ed. p. 47*; Salvadori, Cat. Birds Brit. Mus. 
XXvii. p. 477°. 
Interscapulio et scapularibus elongatis nigris; dorso toto, uropygio et supracaudalibus cinereis ; tectricibus 
marginalibus nigris, majoribus quoque basaliter nigris ; tectricibus primariorum et primariis nigricantibus ; 
