446 
SYSTEMATIC SYNOPSIS. —PICABI^. 
suborders, not however insisting in the least upon the question of taxonomic rank, but simply 
employing the terms conformably with my usage in other cases. The three groups may be here 
tabulated, with remarks calculated to give an idea of their composition : — 
I. Cypseliformes — including only the three families Cijpselidce, Caprimulgidce, and 
Trocliilidce — the Swifts, Goatsuckers, and Humming-birds. They are birds of 
remarkable volitorial powers ; the wing is pointed, and very long in its feathers and 
terminal portions, though the upper arm is very short. The feet are extremely small 
and weak, and are scarcely if at all serviceable for progression. The hind toe is 
sometimes versatile (among the Swifts) or somewhat elevated (in the Goatsuckers 
and some Swifts) ; the front toes are frequently connected at base by movable web- 
bing (Goatsuckers) , and sometimes lack the normal number of phalanges (among 
Swifts and Goatsuckers) ; but the feet are never zygodactyle nor syndactyle. The 
variously-shaped tail has ten rectrices. One family (Humming-birds) shows the 
tenuirostrcd type of bill ; the other two, the fissirostral, on which account they used 
to be classed with the Swallows. The sternum is broad, with a deep keel, entire or 
doubly notched (rarely singly notched) behind. The syrinx has not more than one 
pair of intrinsic muscles. 
II. CUCULIFORMES * — comprehending the great bulk of the order; in all, about fifteen fami- 
lies, rather more than less. They are only readily limited by exclusion of the charac- 
ters of the preceding and following groups. The sternum is usually notched behind j 
the syringeal muscles are two pairs at most. The feet are generally short ; the dis- 
position of the toes varies remarkably. In the Coliidce, or colies, of Africa, all the 
toes are turned forward. In the Trogonidce, the second toe is turned backward, so 
that the birds are zygodactyle, but in a different way from all others. Families with 
the feet permanently zygodactyle in the ordinary way by reversion of the fourth, or 
partially so, the outer toe being versatile, are — the Cucididce, or Cuckoos, with their 
near relatives the Indicatoridcs or Guide-birds of Africa; the IlliamphastidcB, or 
Toucans, confined to tropical America and distinguished by their enormous vaulted 
bill; the Musophagidcc, Plaintain- eaters or Touracos, of Africa; the Biicconidce and 
Cajntonida;, or fissirostral and scansorial Barbets of the New and chiefly of Old World 
respectively ; and the GalbulidcB, or Jacamars, of America. (The Cucididce and 
Musophagidce are by Garrod placed together with Gallinaceous birds.) In the 
remaining groups, the toes have the ordinary position, but sometimes offer unusual 
characters in other respects. Thus in the Alcedinidcs (Kingfishers), and Blomotidce 
(Motmots or Sawbills), the middle and outer toes are perfectly coherent for a great dis- 
tance, constituting the syngenesious, syndactyle or anisodactyle foot. The Bucerotidce, 
or Hornbills, of the Old World, characterized by an immense corneous process on the 
bill, are relatives of the Kingfishers ; so are the Todidce, a group of small brightly- 
colored birds of Mexico and the West Indies. Other forms, all Old World, are the 
MeropidcB or bee-eaters, the UpiipidcE or Hoopoes, and the CoraciidcB or Rollers, with 
their allies the Leptosomatidis, of Madagascar. 
III. PiciFORMES — comprising only three families, the lyngidce, or Wrynecks, with one 
genus and four species, of Europe, Asia, and Africa ; the Picumnidcs, with one or two 
genera and nearly thirty species, chiefly American ; and the Picidcs or true Wood- 
peckers. The digits are permanently paired by reversion of the fourth, except in 
two tridactyle genera, having no hind toe proper; there is a modification of the 
* While the Cypseliformes and Piciformes are each of them well characterized and perfectly defined groups 
of birds, the reverse is the case with the Cuculiformes, — a, mixed lot requiring to be reconstructed by exclusion of 
some of the families here given as entering into its composition. The Trogonidoi have already been eliminated 
by Sclater under the name of Haterodactyli. 
