2 columb^:. 



Hallux connected with the flexor longus hallucis and not with 

 flexor perforans digit orum ; the two deep plantar tendons are not 

 free, but united with a vinculum. 



The Pigeons build a nest of a very simple structure, composed of 

 twigs, and generally placed in a tree. The eggs are generally two, 

 and constantly white ; some species lay only one egg. The newly- 

 hatched pulli are naked and altogether helpless, and for a time 

 they are nourished with a secretion from the well-developed crop. 



The Pigeons are phytophagous and cosmopolitan ; about 470 

 species are known. 



The affinities of the Pigeons are rather obscure, but, according to 

 Huxley, they are closely allied to the GaUince, and in some respects 

 also to the Owls and the Vultures. 



Key to the Suborders. 



a. Wings adapted for flight ; furcula fully 



developed ; basipterygoid processes pre- 

 sent and placed medially 1. C0LUMB2E, p. 2 



b. Wings rudimentary, not adapted for flight ; 



furcula much reduced ; basipterygoid 

 processes absent. (Huxley, P. Z. S. 

 1867, p. 434.) 2. DIDI, p. 628. 



Suborder I. COLUMBjE. 



Key to the Families. 



Nostrils linear and parallel to the edges or 

 tomia of the upper mandible ; bill not 

 hooked. 

 a'. Head not crested, or if crested with the 

 barbs of the feathers joined together. 

 a". Tarsus rather short, generally shorter 

 than the middle toe. (Tree-Pigeons.) 

 a'". Soles very broad, each toe with 

 the skin expanded on the sides ; 

 tail with 14 feathers (except in 

 the genera Phabotreron and Hemi- 

 pJiaga with 12, and in the sub- 

 genus Thoracotreron with 16) ; 

 tarsus feathered more than half 

 its length 1 . Treronidae, p. 3. 



