198 
URXNATRICES. 
pillars ash-grey; wings as in the male, lower parts white, 
with the sides partly grey. Young nearly similar to the fe- 
male. 
Male, 15§, 24, 7tv> Itv* Hi - ? fv* Female, 14, 23. 
This species, which is a native of the Arctic regions of both 
Continents, and retires southward in the end of October, vi- 
sits the southern parts of England in great numbers, but is 
rarely met with in Scotland. 
Mergus Albellus, Linn. Syst. Nat. i. 209. — Mergus Albel- 
lus, Lath. Ind. Ornith. ii. 831. — Mergus Albellus, Temm. 
Man. d ? Ornith. ii. 887. Mergus Albellus, Pied Smew, Mac- 
Gillivray, Brit. Birds, v. 
Having examined the Lamellirostral families of the web- 
footed series of birds, analogous in many respects to the fa- 
milies of the Scrapers among the free-toed species, we have 
seen that, in the Mergansers, an evident transition is made 
to the Divers, which not only swim, but procure their food 
under the surface of the waters. These birds, of which the 
species that occur on our coasts are sufficiently numerous to 
afford a correct idea of the structure and habits distinctive 
of the order to which they belong, are so large, so conspicu- 
ous, so well characterized, and so remarkable in their habits, 
that one can easily render himself in some degree acquainted 
with them. 
ORDER XVIII. TJRINATRICES. DIVERS. 
The birds to which I give the general name of Divers, 
simply because they are universally distinguished by the 
faculty implied by that term, and because all of them 
procure their prey by pursuing it in the liquid element, 
agree in presenting the following characters. They 
have the body large, of an elliptical form, more or less 
depressed ; the neck generally strong ; the head oblong, 
anteriorly compressed. Bill of moderate length, strong, 
tapering, compressed, pointed, opening rather widely, and 
more or less dilatable. Nostrils basal, small, oblong ; 
