146 
NORTH AMERICAN BIRDS. 
£3 
at base, or with abnormal ratio of phalanges in length and number, or 
both. Sternum deep-keeled, usually entire or else doubly notched or 
perforate. Syringeal muscles not more than one pair. 
b. Cuculi. Palate desmognathous. Wings not peculiar in brevity of 
proximal or length of distal portions, and with first primary not reduced. 
Tail of eight to twelve rectrices. Bill of indeterminate form, never 
cered; tongue not extensile. Feet variously modified by versatility 
or reversion of either first, second, or fourth toes, or by cohesion for a 
great distance of third and fourth, or by absence or rudimentary condi- 
tion of first or second ; often highly scansorial, rarely ambulatorial. 
Syringeal muscles two pairs at most. 
c. Pici. Palate u exhibiting a simplification and degradation of the 
segithognathous structure” (Huxley) ; wings bearing out this passerine 
affinity in the common reduction of the first primary and the restriction 
of the greater coverts. Tail of ten perfect rectrices and usually a sup- 
plementary pair. Rostrum hard, straight, narrow, subequal to head, 
with commonly extensile and vermiform but not furcate tongue. Feet 
highly scansorial. Fourth toe permanently reversed ; basal phalanges 
of toes abbreviated. Sternum doubly notched. Salivary glands highly 
developed. Hyoidean apparatus peculiar. 
C. FSITTACI. Bill enormously thick, short, high, much arched from the 
base, the upper mandible strongly hooked at the end, cered at base, and 
freely movable by complete articulation with the forehead, the under man- 
dible with short, broad, truncate symphysis. Feet permanently zygodactyle 
by reversion of the fourth toe, which articulates by a double facet. Tarsi 
reticulate. Syrinx peculiarly constructed of three pairs of intrinsic muscles. 
Tongue short, thick, fleshy. Sternum entire or fenestrate. Clavicles weak, 
defective, or wanting. Orbit more or less completed by approach or union 
of postorbital process and lachrymal. Altricial ; psilopaedic. 
D. RAFTORES. Bill usually powerful, adapted for tearing flesh, strongly 
decurved and hooked at the end, furnished with a cere in which the nostrils 
open. Feet strongly flexible, with large, sharp, much curved claws gradually 
narrowed from base to tip, convex on the sides, that of the second toe larger 
than that of the fourth toe, and the hinder not smaller than the second one. 
Feet never permanently zygodactyle, though fourth toe often versatile; 
anterior toes commonly with one basal web; hallux considerable and 
completely incumbent (except Cathartidce). Legs feathered to the suffrago 
or beyond. Rectrices twelve (with rare exceptions) ; primaries sinuate or 
emarginate (with rare exceptions). Sternum singly or doubly notched 
or fenestrate. Palate desmognathous. Carotids double. Syrinx wanting or 
developed with only one pair of muscles. Altricial ; the young being weak 
and helpless, yet ptilopaedic, being downy at birth. 
E. CQLUMBJE, Bill straight, compressed, horny at the vaulted tip, which 
is separated by a constriction from the soft membranous basal portion. Nos- 
trils beneath a soft, tumid valve. Tomia of the mandibles mutually apposed. 
Frontal feathers sweeping in strongly convex outline across base of upper 
mandible. Legs feathered to the tarsus or beyond. Hallux incumbent (with 
few exceptions), and front toes rarely webbed at base. Tarsus with small 
scutella in front, or oftener reticulate, the envelope rather membranous 
than corneous. Head very small. Plumage without after-shafts. One pair 
of syringeal muscles. Sternum doubly notched, or notched and fenestrate 
on each side. Carotids double. Palate schizognathous. Monogamous, 
and highly altricial and psilopaedic. 
