Bill of moderate length, slender, straight, a little broader than high
at the base, compressed toward the end; upper mandible with its dorsal
line straight and declinate, convex at the end, the tip small, acute,
the notches small; lower mandible with the angle of moderate length
and narrow, the dorsal line straight, the sides convex, the tip
narrow. Nostrils basal, oval or oblong. Head rather large, ovate; neck
short; body rather slender. Feet of ordinary length, slender; tarsus
compressed, with seven anterior scutella; toes moderate, compressed;
first stouter, second and fourth nearly equal, third much longer, and
adherent at the base; claws moderate, arched, slender, compressed,
acute. Plumage soft and blended. Bristles short or weak. Wings of
moderate length or long; the first quill very small, the second,
third, and fourth longest. Tail long or of moderate length, of twelve
feathers. Tongue, sagittate, slender, tapering to a slit and lacerated
point. Œsophagus rather narrow, without crop; proventriculus
oblong; stomach a gizzard of moderate strength, with the muscles
distinct, the epithelium dense and rugous; intestine of moderate
length; cœca very small. Trachea simple, with four pairs of
inferior laryngeal muscles.
Of this family, which in Europe is so numerous, there are in North
America only two genera, _Regulus_ and _Sialia_, the former composed
of very small birds, allied in manners to the Tits, the latter
approaching the Thrushes in form. The connecting links being wanting
with us, these genera might seem at first sight very dissimilar.
GENUS I. REGULUS, Cuv. KINGLET.
Bill short, straight, very slender, a little broader than high at the
base, compressed toward the end; upper mandible nearly straight in its
dorsal outline, the edges slightly notched, the tip a little
declinate, acute; lower mandible with its outline ascending, nearly
straight, the tip acute. Nostrils basal, elliptical, concealed by the
reversed feathers. Head large, broadly ovate; neck short; body short.
Legs rather long; tarsus slender, longer than the middle toe, much
compressed, scutella blended, excepting the lower four toes, rather
small, much compressed, hind toe large; lateral equal; claws rather
long, arched, much compressed, acute. Plumage very loose and full.
Short bristles at the base of the bill. Feathers of the head elongated
and silky in the adults. Wings of ordinary length, with the first
quill very small, the fourth and fifth longest. Tail of ordinary
length, emarginate.