CHAPTER XII. 

 Order ColumbSD. Columbine Birds. 



This order is essentially characterized by the structure 

 of the bill. The tip is convex and corneous, some- 

 what contracted in length, and provided with a soft swol- 

 len basal membrane, which is perforated by the nostrils. 

 The three anterior toes are ordinarily cleft, and sometimes 

 furnished with a slight basal web ; the posterior one 

 is generally insistent or not clearly elevated. The feet 

 are never elongated ; tarsus, either scutellate or quite 

 feathered in front ; reticulate, laterally and posteriorly ; 

 commonly shorter than the toes. The integument is mem- 

 branous, rather than horny. The syrinx has a single pair 

 of internal muscles ; the carotids are two in number ; and 

 the sternum two notched, or notched and fenestrate. The 

 plumage is devoid of aftershafts. 



This order, as at present constituted, embraces three 

 families ; viz : Dididce, which contains the recently 

 extinct dodo ; Didunculidce, as illustrated by the singular 

 tooth-billed pigeon of the Navigator Islands ; and the Co/- 

 umbidcc. The columbine are certainly closely allied to 

 the rasorial birds, but are assigned to their present position, 

 in accordance with the characters above set forth. The; 

 terminate the first great subclass of aerial birds, or the 

 Insessorial series. 



Family ColUHlbidse. Pigeons. 



This family, with a single exception, may be readily iden- 

 tified by their resemblance to the common dove or pigeon. 

 The peculiar arrangement of the frontal feathers which pass 

 athwart the base of the bill and are projected upon the cul- 



