326 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, Pliabotreron, and Megaloprepia, 

 acuminate in Ectopistes, 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 Turtur, or those 

 of the breast, as in some species of Macropygia, Ptilopus, and 

 Phaenorrkina ; the neck, moreover, is hackled in Caloenas and 

 Lopholaemus, and the body -plumage is ger orally narrow with 

 widely-separated barbs in Chrysoenas. Five members of Plilo- 

 goenas have a patch of stiff feathers over the crop ; while the 

 splendid decomposed crest of Gfoura is exceptionally striking, and 

 more ordinary tufts grace the head in Lopholaemus, Coryplioenas, 

 Lophophaps, Ocypliaps, 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, JKeinwardtoenas, 

 Macropygia, Turcwoena, 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, being 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 Oarpophaga latrans has the interior beset with similar 

 conical prominences, correlated with a diet of hard fruit. Phaenor- 

 rkina has these cones still more developed, and Ptilopus agrees with 

 Drepanoptila in possessing four pads in the above organ instead 



