26 THE CLASSIFICATION OF BliJDS 



tract defined on the neck; but a minute inquiry into their 

 characters shows some very remarkable variations from the 

 normal avian type. Some of these variations are so extraordinary 

 that they have been considered of sufficient importance to warrant 

 the placing of their possessors in separate orders. For example, 

 the absence of the uncinate processes of the ribs of the Pala- 

 medeidce, though it is a unique character amongst birds, has had 

 an exaggerated taxonomic character attached to it. There is no 

 reason whatever for the supposition that it is an archaic character 

 which has been retained by this family alone. There can scarcely 

 be any doubt that the Palamedeidce once had uncinate processes 

 on their ribs, and that they lost them after having acquired the 

 peculiar characters which they inherited from the ancestors of the 

 Anatidce and Phcenicopteridce, otherwise these peculiar characters 

 must have been independently acquired by one or the other of 

 them. There is, however, a curious instance of the independent 

 acquisition of a remarkable character by a family in the Ciconii- 

 formes. The Ibididce are schizorhinal, like the Charadriiformes. 



The twelve families which form the Order ClCONHFOKMES 

 may be conveniently grouped in three Suborders, which has 

 every appearance of being a natural arrangement, though some 

 difference of opinion exists as to the nearest affinities of the 

 Phcenicopteridce. 



The three Suborders may be diagnosed as follows: 



Herodiones. Ciconiiformes with altrical young ; free hallux ; 

 and no basipterygoid processes. 



Ansercs. Ciconiiformes with prsecocal young; the mandible 

 much produced and recurved behind its articulation with the 

 quadrate ; and holorhinal nasals. 



Stcganopodes. Ciconiiformes with the hallux united to the 

 second digit by a web ; mandible truncated behind the quadrate. 



2. ANSERES. 



In spite of the supposed affinity of the Flamingoes with the 

 Storks, the AN SERES are an extremely easy group to diagnose. 

 They are the only desmognathous birds whose young are able to 

 run about a few hours after they are hatched. It is probable that 

 both these characters may have been independently acquired, but 

 other diagnostic combinations of characters can easily be found. 

 In no other birds is the mandible so much produced and recurved 



