SUB-ORDER 



COLUMBAE. 



Ch The basal portion of the bill covered by a soft skin, in which are situated the nostrila, overhunor by an incumbent fleshy 



valve, the apical portion hard and convex. The hind too on the same level with the rest ; the anterior too without membrane 

 at the base. Tarsi more or less naked ; covered laterally and behind with hexagonal scales. 



The preceding diagnosis expresses sufficiently the chief characters of this sub-order, or rather 

 order, divided by Bonaparte into two tribes, one Pleiodi, including Didunculus, of Peale, the 

 other Gyrantes, or true doves. The Gyrantes are divided by the same author into Treronidae, 

 Culumhidae, Caloenidae, and Gouridae, characterized as follows : 



Tkeronidae. — Bill robust, tumid ; rictus ample. Feet short, thick, half feathered ; toes 

 fleshy ; claws strong, hooked. Tail feathers, 14, Feathers soft, without metallic lustre ; 

 prevailing color green ; wing with a yellow band. The species are frugivorous and arboreal. 

 They are confined entirely to the old world, and are especially abundant in the islands of the 

 Pacific. 



CoLUMBiDAE. — Bill horny at the tip. Tail feathers 12 ; only occasionally 14. Head smooth. 

 ITniversally distributed. 



Caloenidae. — Bill lengthened ; cere swollen ; cervical feathers elongated, acute, pendulous. 

 Dorsal accuminate. Tail feathers 12. The single species, Caloenas nicobarica, confined to the 

 East India islands. 



Gouridae. — Head conspicuously crested ; tail feathers 16. The two species confined to 

 New Guinea. 



The bill of the Columhae is always shorter than the head, thinnest in the middle ; the basal 

 half covered by a soft skin ; the apical portion of both jaws hard ; the upper very convex, 

 blunt, and broad at the tip, where it is also somewhat decurved. There is a long nasal groove, 

 the posterior portion occupied by a cartilaginous scale, covered by a soft cere-like skin. The 

 nostrils constitute an elongated slit in the lower border of the scale. The culmen is always 

 depressed and convex. The bill is never notched in the true doves, though Didunculus shows 

 well defined serrations. The tongue is small, soft, and somewhat fleshy. 



The wing has ten primaries, and eleven or twelve, rarely fifteen, secondaries, the latter 

 broad, truncate, and of nearly equal length. The tail is rounded or cuneate, never forked. 



The tarsus is usually short, rarely longer than the middle toe, scutellate anteriorly, and with 

 hexagonal plates laterally and behind ; sometimes naked. An inter-digital membrane is 

 either wanting entirely, or else is very slightly indicated between the middle and outer toes.^ 



The valuable monograph of Bonaparte in the second part of Conspectus Avium renders the 

 task of arranging the American Columhae in proper sequence and of determining their synonomy 

 comparatively easy. He divides the family Columbidae, the only one with representatives in the 

 new world, into Lopholaeminae, Coluinbinae, Turturinae, Zenaidinae, and Fhapinae, the second 

 and fourth alone occurring in North America. They may be briefly distinguished as follows : 



CoLUXUJmAE. — Tarsi shorter than the lateral toe ; feathered above. 



Zenaidesae. — Tarsi stout, lengthened, longer than the lateral toes ; entirely bare of feathers. 



'The preceding general remarks are taken chiefly from Burmeister, Thiere Brasilions, Vogol, II, 289. 



