YERTEBRATA. 227 



part often assumes a warty appearance. The feet are as much 

 fitted for walking as perching ; but the tarsus is short and stout, 

 scutellate in front, and sometimes feathered. 



Pigeons, the best known family of this order, are monogamous, 

 and pair for life. They are without a gall-bladder, except in 

 Carpophaga and Ptilopus, and hence, it is said, their placid 

 disposition ; it is wanting, however, in many other birds. Their 

 nests are very simple, a few sticks, or merely a hollow amongst 

 herbage. The males and females sit by turns on the eggs. The 

 two dodos, Didus ineptus and Didus solitarius, are now extinct. 

 They were very heavy birds, incapable of flight, and in other 

 respects very unlike pigeone. Didunculus is an intermediate 

 form. 



Among the members of this order are the common pigeon, 

 supposed to be descended from the rock-dove (Columba livid), 

 wood-pigeon (Columba palumbus), stock-dove (Columba cenas), 

 turtle-dove (Turtur auritus}, passenger-pigeon (Ectopistes migra- 

 torius}, the bronze-wing (Phaps chalcoptera], and the great-crested 

 pigeon of the Indian Archipelago ( Goura coronata}. 



This order with Megapodiidae and Cracidae were the Pullastreae 

 of Sundevall, but in 1872 it became his eighth cohort (Pe- 

 risteroideas) of the Volucres. Didunculidse and Dicliclae are 

 united as a family Didina. Goura is the type of another 

 family Megapeliinae. Cal&nas has also been separated as a 

 family. Pteroclidse are by some writers considered to belong to 

 this order. 



Columbia (Pigeons), phaps. Zenaida. 



Caloenas. Geopelia. Ptilopus. 



Goura = Lophyrus= Turtur (Turtle- 



Megapelia. dove). Didunculida. 



Treron. OEna. Didunculus. 



Vinago. Ectopistes. 



Carpophaga. Chamaepelia. Didida. 



Columba. Macropygia. *Didus (Dodo). 



Order VI. GALLIN.E. 



EASORES. CLAMATORES. ALECTOROMORPH^E. 



Bill mostly rather short, vaulted, edges of the upper mandible 

 overlapping. Nostrils pierced in a membranous space. Hind 

 toe above the level of the others ; claws thick, obtuse, 



Q2 



