The reason of this is as follows. The names of the
Families in Ornithology are made by adding dm to
the name of the typical genus; that is, the genus
which exhibits, imited in itself, the greatest number



• Bechsteik, when speaking of this species, says : — " Instead o^
the common name, tame Swan, I prefer that of Mute Swan, in order to
distinguish this from the Whistling Swan, also called the Wild Swan,
but improperly, for in Russia it is more common to have that tamed
than the one under notice."



THE ORNITHOLOGICAX GUIDE. 75

of the peculiarities observable in the family. Thus
Falco is the typical genus of the diurnal birds of
prey ; that family is consequently termed Faleonidee.
But it sometimes happens that Naturalists cannot
agree as to which is the typical family : thus Selby
thinks that Fringilla is typical of the family in
which that genus is found — ^he therefore calls the
family the Finch-family and Fringillidae. In the
CycL Nat. Hist.^ the writer thinks that Carduelis
is the typical genus — the family, according to this,
must be called the Goldwing-family and Cardue-
lidae. There is difference of opinion again with
regard to which is the typical genus of the SilviadaBy
some conjecturing it to be Ficedula (called accord-
ingly FicedulidseJ others sajdng Regulus (called
accordingly Regulidas) and yet others pronounce
Silvia to be the type of the Family ; they thei-efore
call the family the Warbler-family and Silviadas, I
am inclined to agree with the latter. The genus
Swallow (Hirundo) is usually taken as a typical
genus ; the family is consequently called the Swal-
low-family and Hirundinidas : Mr. Blyth, however,
in the Magazine of Natural History^ (vol. VIT, p.
