C A P I T O N I D i E .
KÉSUMÉ OF T H E HISTORY.
THE Capitonidoe, or Bucconidoe of Brisson, so called on account of the swelling at the base
of the lower mandible, have occupied many different places in the "schema naturee"
according to the classifications of various systematists ; and a concise resume of t h e positions
assigned to them by the principal authors who have treated on their genera, will best serve
to indicate their characteristics.
1788. Gmelin (Syst. Nat. i. p. 405) classifies the "Buccones" as scansorial birds in the
family of Piece, and places them between the Trogonidoe and Cuculidoe : he includes with
t h em the fissirostral Puff-birds of South America under the same generic name. He gives
eleven species of t r u e Capitonidoe, being all t h a t were then known.
1790. Latham, in his ' I n d e x Ornithologicus,' follows the same classification, but adds five
species, making sixteen in all.
1811. Illiger (Prod. Mamm. et Av.) introduces the genus Pogonias for t h e African species,
retaining Bucco for the Asiatic. This is t h e first division of t h e family into genera.
1816. Vieillot (Diet. d'Hist. Nat.) advances a considerable step beyond his predecessors,
as will be seen from the following notes gathered from his ' Dictionary of Natural History.'
"Barbus. This genus is divided into two sections, the first has the upper mandible
furnished with one or two teeth. The second has a hook at the tip of the bill. They are
wood-haunting zygodactyle birds. The first come from West Africa, and are the true Barbus ;
t h e second come from the New World, and are the Tamatias of Buffon." Further on in
t h e book he divides the true Barbus into two groups, and introduces the genus Cabezon or
Capito for those Barbus which have hitherto erroneously been classed with the species t h at
have grooved or toothed bills, while the distinguishing feature of the genus Capito is a
smooth bill ; under this generic name he places fifteen species ; among them are some now
classified under Megaloema and Xantholoema, as well as some that are still classed as Capito.
1818. Buffon, in his later work, classifies t h em as " Scansores," between the Yuncinoe and
the Ramphastidoe, and divides them into two families—Tamatia of the New World, and
Barbus of the Old World. The former, however, includes six fissirostral Barbets and only
two scansorial ; the scansorial Barbets are included by an error ; and this is t h e first author
who has drawn a distinction between the two groups.
1823. Banzoni, in the ' Elem. di Orn.,' introduced the generic name of Trachyphonus for
the long-tailed African subgroup, type T. cafer.
discovery of such facts when t h e localities t h e y inhabit shall have been more closely watched ;
and it becomes necessary to stretch our definition still further, and assume that where dif
ferent geographical distribution is found permanently associated with a difference of size and
colouring, i t will simplify matters t o describe each form separately, even though interbreeding
may take place at the line of junction.
Having thus eliminated t h e question of affinity, the grouping of t h e birds into subfamilies
and genera on arbitrarily selected differences in structure becomes a matter of extreme simplicity,
and bases itself upon intelligible grounds; and we are thus enabled to make divisions
on such features as t h e shape of t h e bill, and t h e amount of rictal bristles, which, t h o u g h of
comparatively small value in determining relationships, are particularly useful in arbitrary
groups: they are easy of definition, sufficiently prominent to catch the eye ; and, last but not
least, they are equally available to those who study the birds in life, and to the less fortunately
situated naturalists whose acquaintance with most birds is necessarily limited to an
examination of the dry and distorted skin.
Of t h e two features which we have selected, one, t h e rictal bristles, possessed as they are
by many widely differing groups of birds, completely puzzles u s ; and after studying the birds
for some years inside and outside, in life and in death, we are unable even to hazard a guess
at the purpose they are meant to serve; the other, t h e bill, so far from being a typical
feature in the scansorial group, is the one which, as Mr. A. 11. Wallace has pointed out in
a very able paper on the natural affinities of birds, presents the greatest variety of form;
and had we professed to have been guided by affinities, t h e selection of these features might
have laid us open to the charge of inconsistency. For the rest, though the grouping is
arbitrary, it is for the most part familiar, and we have avoided as far as possible any innovations
in the nomenclature. We should prefer ourselves sinking the generic names
altogether, and retaining only the three subfamilies; but the definitions would have lost in
clearness and conciseness what they gained in limitation of quantity, and, as far as we can
judge, identification will be simpler with the minor subdivisions and restricted genera
retained; and the advantage thus gained may be found adequate compensation for the extra
t a x on t h e memory. Those who do not t h i n k so will of course drop t h e minor subdivisions;
but those who do, will, we think, find the grouping sufficiently clear, and, though based on
no affinity, still containing nothing to outrage the doctrines of the supporters of a natural
theory.
I n conclusion a few remarks are necessary with regard to t h e word " type " so frequently
used in this as in all other works on natural history. The word has two distinct applications:—
one, the philosophical sense, in which community of descent is implied, and which signifies
either the common progenitor, or the existing species possessing its peculiar characteristics
most strongly marked; the other, the technical sense, meaning simply the species or genus
to which the specific or generic name was first applied. It is in this latter sense t h a t it has
been used throughout the body of the work, while in this introductory chapter it has been
used in t h e former or philosophical sense.