494 BIRDS OF ILLINOIS. 



ORDER COLTJMB.2E. THE PIGEONS OR DOVES. 



CHAB. Basal part of the bill tumid and covered with a soft skin, in which are situated 

 the narrow, longitudinal nostrils, overhung by a valve-like scale or covering; terminal 

 portion of the bill hard; the culmen more or less strongly arched. Hind toe usually in- 

 cumbent, and front toes generally cleft to the extreme base. Plumage peculiarly dense, 

 the feathers without aftershafts, and very easily detached from the skin. Primaries ten; 

 secondaries, eleven to fifteen; rectrices, twelve to fourteen. 



The number of families composing this order is at present some- 

 what uncertain. Whatever the number, however, America possesses 

 but one, the Columbidce, or true Pigeons, whose characters are as 

 follows : 



FAMILY COLTJMBID-ffi. THE PIGEONS. 



"CHAE. The basal portion of the bill covered by a soft skin, in which are situated the 

 nostrils, overhung by an incumbent fleshy valve, the apical portion hard and convex. 

 Thohind toe on tho same level with the rest; the anterior toes without membrane at 

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



"The bill of the Columbidce is always shorter than the head, thin- 

 nest in the middle ; the basal half covered by a soft skin ; the apical 

 portion of both jaws hard; the upper one 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. 



