^0 



~""^ COLUMBA LEUCOCEPHALA. 



seldom exceeding twice its width in length. The marginal indentations are four but the 

 two inner are often inclosed anil do not occupy more than one third of the length of the 

 .-iernum. The keel is high and extends nearly or quite the entire length of the sternum. 

 There is no manubrium. The furcula is short and weak. Scapula, not truncated but 

 pointed. The lesophngus is dilated into a large double crop which, during the nesting sea- 

 son, is provided with a coating of glands from which exudes a kind of milky fluid which is 

 mixed with the macerated grain, and the young are fed with the mixture by regurgita- 

 tion. This crop is supported by a muscle which extends from the middle to the skin of 

 the neck. The sterno-trachealis is not especially strong and there are one or two pairs of 

 ether laryngeal muscles which, however, do not extend over all the half rings. The tym- 

 jKuiil'orm membrane is present but there is no semilunar membrane, although there is an os 

 transversalo. The proventriculus is remarkably well developed. The stomach is very 

 muscular and is lined with a hard, rugose membrane. The fold of the duodenum is not 

 long and incloses a large double pancreas. The intestines are quite small and long but 

 the coeca is either absent or very small. The tail is either square, rounded, or pointed 

 but never forked. The eggs are seldom more than two in number and the young, when 

 first hatched, are naked. 



FAMILY I. COLUMBIDiE. THE DOVES. 



The sternum is wide, exceeding one half the length. The tip of the keel is considerably 

 rounded. 



The size is usually large. Head, small. The tail has either twelve or fourteen feath- 

 ers and the tarsus is slightly feathered in front. This is a large family and the member.-* 

 are generally distributed throughout the world. 



UENUS I. COLUMBA. THE DOVES. 



(Jen. Cii. Bill, rather short and stout. Tail, short, and rounded or square. Sternum, rather narrow. Caeca , mod- 

 rately well developed. 



Members of this genus are quite large, rather dull in color, but occasionally have some conspicuous white markings. 

 There is but one species within our limits. 



COLUMBA LEUCOCEPHALA. 



White-headed Dove. 



Columba leucocephala Linn. Syst., Nat., I; 1766, 281. 



DESCRIPTION. 



Sp. Cii. Form, robust. Size, quite large. Sternum, stout. Tongue, long, ratlier thin, broadening toward tip which 

 is hiu-ny and pointed. Coeca, small. Tail, rounded. 



Color. Adult male. General color throughout, dark slaty-blue, becoming very dark on the tail above and black be- 

 neath. Top tf head, from bill to nape, pure white, margined behind with bluish which ra])idly becomes rich purplish- 

 brown on the hind neck. The neck on sides and lower portions is iridescent gi-een, with golden reflections, wiule each 

 feather is margined witli black. 



Adult female. Quite «'imllar to the male, but differs in having the white head slightly overwashed with dusky and the 

 remaining colors somewhat duller. 



Nestlinijs. Are at first nearly black, then gradually a.ssume the adult plumage. Bill, red, bluish-white at tip, feet, 

 purplish-rill, and iris, yellowish-white, in all stages. 



