110 



ORTHOGENETIC EVOLUTION IN PIGEONS. 



is connected with the anterior bar, which is narrow and widely separated from the 

 tips of the feathers. The tail has an apical dark-gray band and a subterminal white 

 bar. The whole color shows a reduction of pigment carried beyond the condition 

 seen in C. livia. This makes the species of considerable interest from my standpoint 

 of orthogenetic loss of pigment. I should place it as higher than C. livia; C. leuconota 

 as lower. 



Text-fic.ore 23. — Columba rupeslris (Hayashi del., after Bonaparte, ex Pallas, Icon. d. Pig. lNo", pi. i.xxv). 



The general coloration of this species shows a greater reduction of pigment than that of the rock-pigeon. The 

 lower half of the posterior wing-bar is not present. The pigment of the bars has retreated farther from the tips of 

 the feathers. A broad white subapical tail-band. 



According to Salvadori (page 251), two varieties of this pigeon are now recognized, 

 Rothschild and Hartert having separated the paler form from the Altai from that 

 of eastern Siberia. The same author further states that the wing-coverts and scapu- 

 lars of the young have "narrow whitish edges." 



Columba oenas, the stock-dove, was for long confused with the rock-pigeon. It 

 has, however, advanced beyond the rock-pigeon, the wing-bars being reduced to 



