By Richard C. McGregor.
Class AVES.
Oviparous, warm-blooded, amniotic vertebrates which have their anterior
extremities transformed into wings. Metacarpus and fingers carrying
feathers or quills. With an intertarsal joint. Not more than four
toes of which the first is the hallux. (Gadow.)
Subclass CARINATÆ.
Sternum with a keel; scapulæ and coracoids fused forming an acute
or a right angle; foramen ischiadicum present; distal six or seven
vertebræ fused to form the pygostyle.
Orders.
a1. Hind toe connected by a web to the inner toe ... Pelecaniformes
(p. 200)
a2. Hind toe not connected by a web to the inner toe.
b1. Nostrils tubular.
c1. Bill strong and decidedly hooked at the tip
... Procellariiformes (p. 84)
c2. Bill weak, very small, gape very wide ... Caprimulgi in
Coraciiformes (p. 295)
b2. Nostrils not tubular.
c1. Cutting edges of bill more or less distinctly fringed or
serrated, tip of bill rounded ... Anseriformes (p. 184)
c2. Cutting edges of bill not fringed.
d1. Rectrices rudimentary; or if evident not prominent, being
short, soft, and hidden by the upper coverts.
e1. Tarsus flat; toes lobed ... Colymbiformes (p. 82)
e2. Tarsus normal; toes not lobed.
f1. Hind toe wanting ... Hemipodii (p. 17)
f2. Hind toe present. ... Excalfactoria and Megapodius in
Galliformes (p. 9)
d2. Rectrices not rudimentary; if short not hidden by upper
coverts.
e1. Anterior toes distinctly webbed and tarsus shorter than
tail. ... Lariformes (p. 85)
e2. Anterior toes not distinctly webbed; or, if webbed,
tarsus decidedly longer than tail; or else bill extremely
small with gape very broad and deeply cleft.
f1. Lower portion of thighs naked; or, if feathered, the
bill lengthened and grooved along each side, the outer and
middle toes separated for their entire length.
g1. Hind toe well developed and inserted on the level of
the anterior toes; claws not excessively lengthened; loral
or orbital region or both naked ... Ardeiformes (p. 157)
g2. Hind toe if present, small and inserted above the
level of the rest; or else size of bird small (less than
1 meter), loral and orbital regions fully feathered and
middle claw not pectinate.
h1. If more than 1 meter long the hind toe short and
elevated; if less than 1 meter long the hind toe not
elevated.
i1. Size very large; hind toe small and
elevated. ... Gruiformes (p. 155)
i2. Size medium to small; hind toe not
elevated. ... Ralliformes (p. 65)
h2. Less than 1 meter long, usually much less; the hind
toe if present, short and elevated, or if long the claws
excessively long and wings spurred ... Charadriiformes
(p. 98)
f2. Lower portion of thighs feathered; or else middle and
outer toes united for at least half their length, the bill
if lengthened not grooved along the side.
g1. Bill strongly hooked and with a distinct cere at base
of upper mandible.
h1. Toes three in front; or else outer toe reversible;
claws sharp and powerful.
i1. No facial disk of modified feathers; plumage
normal, compact; nostrils generally not concealed by
bristles. ... Accipitriformes (p. 210)
i2. Eyes surrounded by a disk of modified feathers;
plumage soft and fluffy; nostrils usually concealed
by stiff bristles. ... Strigiformes (p. 249)
h2. Toes two in front and two behind, the outer
toe permanently reversed; claws small and dull
... Psittaciformes (p. 272)
g2. Bill not strongly hooked and without a cere at base
of upper mandible.
h1. Hind toe small and elevated ... Galliformes (p. 9)
h2. Hind toe or toes well developed and on the same
level as the anterior toes.
i1. Upper mandible with a soft swollen
base. ... Columbiformes (p. 23)
i2. Bill without a soft swollen base.
j1. Toes two in front, two behind; rarely two in
front and one behind, then the bill straight and
the rectrices stiff and pointed.
k1. Two toes in front united for their basal joint.
l1. Inner toe reversed, tail graduated
... Trogones (p. 362)
l2. Outer toe reversed, tail nearly
square. ... Scansores (p. 389)
k2. Two toes in front perfectly free.
l1. Bill straight, its tip chisel-shaped;
rectrices stiff, with stiff, pointed tips
... Piciformes (p. 392)
l2. Bill more or less curved; rectrices long and
soft, without stiff, pointed tips ... Coccyges
(p. 363)
j2. Toes three in front, one behind; rarely two in
front and one behind, then the tail soft; or rarely
four toes turned forward and arranged in pairs.
k1. Claw of hind toe shorter than that of third
toe; feet weak, or feet strong and two toes united
for their basal joint ... Coraciiformes (p. 295)
k2. Claw of hind toe equal to or longer than that
of middle toe.
l1. Outer and middle toes united for their
basal joint; bill broad; eye surrounded by a
fleshy wattle; tail graduated ... Eurylæmiformes
(p. 410)
l2. Outer and middle toes not united; toes
four in number; rectrices twelve with rare
exceptions; bill variable in shape, never
extensively membranous, softly tumid, nor cered
... Passeriformes (p. 413)
Order GALLIFORMES.