3 26 CHARADRIIFORMES CHAP. 
on each side of the digits. The rounded wings are commonly 
long, but are short in Ground-Pigeons, and aborted in the 
flightless Dididae, the primaries numbering eleven and the 
secondaries from ten to seventeen; the former are bifurcated at 
the tip in Drepanoptila, attenuated in some members of Ptilopus, 
Oxypelia, Peristera, and Leptoptila, while one or more of the 
three outer feathers is not uncommonly scalloped. The tail 
varies considerably in form and dimensions, being wedge-shaped 
in Sphenocercus, rounded in Zenaida, Phabotreron, and Megaloprepia, 
acuminate in Hctopistes, long and graduated in Oena, Macropygia, 
and Reinwardtoenas, and so forth. The rectrices range from 
twelve to twenty, sixteen being the normal number in the 
Gourinae, twelve in the Columbinae, and fourteen in the 
Treroninae. The neck-feathers may be bifurcated, as in Alec- 
toroenas, Columba guinea, and occasionally in Zurtur, or those 
of the breast, as in some species of Macropygia, Ptilopus, and 
Phaenorrhina ; the neck, moreover, is hackled in Caloenas and 
Lopholaemus, and the body-plumage is generally narrow with 
widely-separated barbs in Chrysoenas. Five members of Phlo- 
goenas have a patch of stiff feathers over the crop; while the 
splendid decomposed crest of Gouwra is exceptionally striking, and 
more ordinary tufts grace the head in Lopholaemus, Coryphoenas, 
Lophophaps, Ocyphaps, and elsewhere. The forehead is sometimes 
nearly bare, as are the lores and eyelids in Gymnophaps ; naked 
red or yellow orbits are found in Gymnopelia, Reinwardtoenas, 
Macropygia, Turacoena, Didunculus, and Columba gymnophthalma, 
not to mention other instances; while the tendency reaches its 
height in the huge circumocular wattles of several fanciers’ races. 
In Serresius a feathered “saddle” extends over half the culmen. 
The furcula is U-shaped, bemg much reduced in the Dididae ; 
the syrinx is remarkable for the asymmetrical union of the 
sterno-tracheal muscles; the tongue is lanceolate; the impervious 
nostrils are linear in the Columbidae and Didunculidae, oblique 
in the Dididae. The crop is more highly developed than in 
other Families. The gizzard of Caloenas is remarkable for an 
indurated horn-like patch on each side of the epithelial lining, 
that of Carpophaga latrans has the interior beset with similar 
conical prominences, correlated with a diet of hard fruit. Phaenor- 
rhina has these cones still more developed, and Ptilopus agrees with 
Drepanoptila in possessing four pads in the above organ instead 
