COLUMBA. 395 
Genus COLUMBA. 
The genus Columba was included by Linnzus in the 12th edition of his 
‘ Systema Nature’ published in 1766 (i. p. 282). It is impossible to guess 
which species Linnzus considered typical. The first species mentioned by 
him, the Rock-Dove (his Columba enas), has been generally admitted to be 
the type. 
Ornithologists have not yet succeeded in discovering any structural 
characters by which the Pigeons may be grouped into natural genera. 
The species in the genus Columba are distinguished by their moderately 
short and nearly square tails, consisting of twelve feathers, moderately 
stout bills, and by the prevailing slate-grey colour of the plumage, which 
is glossed with metallic tints. The wings are moderately long and pointed. 
The tarsus is very short and stout, scutellated in front, finely reticulated 
behind, and the upper portion is feathered. 
There are about fifty species in this genus. ‘Twenty of these are found 
on the American continent, and are somewhat aberrant in their coloration, 
and may possibly be generically distinct. Of the species found in the Old 
World, half belong only to the Ethiopian Region, and the remaining half 
are distributed in the Palzarctic and Oriental Regions. Three only are 
found in Europe, all of which are residents in the British Islands. 
The birds in this genus breed both in rocks and forests, but they are in 
the habit of wandering sometimes for a considerable distance into the open 
country to feed. Their flight is straight and powerful, and on the ground 
they walk or run with ease. Their notes are very monotonous. ‘Their food 
consists principally of grain, tender shoots, &c. They build slight flat 
nests, and lay two white eggs. 
