6M) 



BRITISH BIRDS. 



Family PELECANID^E, OR PELICAiVS. 



The Pelicans form a well-defined family, although the genera present 

 so much structural variation that many ornithologists divide them into 

 half a dozen families, which may possibly be regarded as subfamilies. 

 They may be diagnosed as follows : 



Tail-feathers with 

 rigid shafts 



very 



Tail deeply forked 



PHAETON. 

 ( Tropic-birds,} 



SULA. 

 (Gannets.) 



PLOTUS. 

 (Darters.) 



PHALACROCORAX. 

 (Cormorants.) 



FREGATA. 



(Frigate-birds. ) 



PELECANUS. 

 (Pelicans.) 



} Central tail-feathers very 

 / much elongated. 



A strongly curved hook at 

 f end of bill. 



Sclater elevates these five groups to the rank of families, and combines 

 them into an order, which he appears to regard as nearest related to the 

 Herons and their allies, and somewhat more distantly to the Birds of Prey. 

 Forbes acquiesced in this arrangement, but associated the Petrels with 

 them in the same great group. Gadow, on the other hand, takes quite a 

 different view of their affinities, and considers the Pelicans, the Penguins, 

 and the Divers to be three highly specialized groups of birds, descended 

 from the branch of which the Ducks are the least changed survivors, 

 When more materials for a classification of birds have been collected, it 

 will probably be found that the Ducks, Flamingoes, Herons, Pelicans, 

 Grebes, and the allies of each of these families form a compact and fairly 

 well-defined order. 



In the modification of their palatal bones, the birds belonging to this 

 family are desmognathous, in which respect they agree with the Ducks, 

 Storks, and their allies, to which probably they are nearly related, and 



