VI TROCHILIDAE 427 
filiform at the tip or narrowed throughout. The secondaries 
are only six, or rarely seven. The tail of ten feathers may be 
long-or short, but differs profoundly in shape, texture, and colour; 
being for example cuneate in Phaéthornis and Sphenoproctus, 
nearly square in Urosticte and Hylocharis, rounded in Adelomyia 
and Polytmus, deeply forked in Sappho, Lesbia, and the four 
genera next named, of which Prymnacantha has the outer pair 
of rectrices very narrow and pointed, Loddigesia, Spathura, and 
Discura spatulate. 
The very characteristic tongue consists of a double tube, 
tapering and separating into two externally lacerated sheaths at 
the tip, which contain the extensile portion. The “horns” of 
the hyoid apparatus are greatly elongated, and pass round and 
over the back of the head, meeting near the top, and thence 
stretching in an ample groove to terminate in front of the eyes. 
This arrangement, analogous to that found in Woodpeckers, 
allows the tongue to be suddenly protruded to a considerable 
distance, and withdrawn again in an instant. The furcula is 
U-shaped; the syrinx has one or two pairs of tracheo-bronchial 
muscles ; the aftershaft is very small; a crop is present; while 
down is absent from both nestlings and adults. 
Except in the “Hermits” (p. 435), the brillant coloration 
almost defies description, the most exquisite metallic! or jewel- 
like hues glorifying a background of green, blue, or brown ; 
while crests, ear-tufts, neck-frills, and pendent beards ending 
in points or forks, add to the effect. Only among the Passerine 
Sun-birds (Nectariniidae) of the Indian and Ethiopian Regions 
can a fitting parallel be found; but these, though often 
erroneously termed Humming-birds, have no connexion with our 
New World group. Lulampis and Pterophanes are exceptional in 
not having dusky remiges. The females are usually sombre in 
comparison, and lack the ornaments of their consorts, which are 
said to be occasionally §maller. The statement that young 
males have no distinctive plumage seems incorrect. 
These gems of Ornithology extend from the north to the 
extreme south of America, the habits differing shehtly with the 
climate ; Selasphorus rufus of the Western United States reaches 
Mt. St. Elias in Alaska, Zvrochilus colubris occurs in the east up 
Kho 
to lat. 57° N., Eustephanus galeritus frequents Tierra del Fuego 
a 
' These are produced by the prismatic surfaces of the feathers, cf. pp. 3, 4. 
