NATATORES. 44;3 



FAMILY IV. PELECANID^E. 



THE Pelecanidae, which form the fourth and an aberrant 

 division of the Natatores, are distinguished from the preced- 

 ing and other families, by the peculiar form of their feet, 

 which consist of four toes, all united by a continuous mem- 

 brane, the hind toe being articulated upon the inner part of 

 the tarsus, and standing at an angle with it, or rather direct- 

 ed to the front. The bill, in the various genera, is strong in 

 form, and commonly longer than the head :^in many the tip 

 is bent downwards, and armed with a strong hook ; in others 

 (where a nearer approach is made to the members of neigh- 

 bouring families) it is strait and sharp-pointed, as^exempli- 

 fied in the genus Phaeton, which closely connects the present 

 with the succeeding family of the Laridee, through the inter- 

 vention of the Terns. In an aberrant group of this family, 

 we find also an obvious approximation, both in external ap- 

 pearance and habits, to the Vulturida and Falconidce, thus 

 forming the link between the raptorial and natatorial orders. 

 Such are the birds belonging to the genus Tachypetes, re- 

 presented by the Frigate Birds, whose form and habits assi- 

 milate them so much to the larger rapacious kind, as to have 

 induced LTNN^US to bestow the specific title of Aquilus on 

 the only species known by him. In this genus the wings 

 are extraordinarily developed, and are equal to the most dis- 

 tant and protracted flights ; the tail is also long and forked, 

 and their legs are very short, with the tarsi feathered, like 

 many of the raptorial order. Their feet are small, in com- 

 parison with others of the family, and the membranes con- 

 necting the toes are so much curtailed, as to be inadequate 

 to the task of swimming. They live almost entirely in the 

 air, and take their prey upon the wing, not by precipitating 

 themselves upon it in the water, like the Gannets, Terns, 



