FREGAT1D.E 21 



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571. Sula leucogastra. Brown Booby. 



Pelicanus sula, Linn., Sijst. Nat. i, p. 218 (1766). 

 Pelecanus leucogaster, Bodd., Tall. PL Enl. p. 57 (1783). 

 Sula sula, Grant, Cat. B. M. xxvi, p. 436 (1898) ; Reichenow, Vog. 

 Afr. i, p. 85 (1900). 



Description. Above, including the head, neck and chest, dark 

 sooty- brown, breast and rest of the under parts pure white ; tail of 

 fourteen feathers. 



Iris silvery-white to grey, bill greenish-white, becoming flesh 

 coloured at the base ; naked skin of the throat bluish, greenish or 

 yellowish, legs pale greenish. 



Length about 28'0 ; wing 15*0 ; tail 7*7 ; culmen 4-0 ; tarsus 1*8. 



Young birds are brown above and below but much lighter than 

 the adults. 



Distribution. The Brown Booby is found throughout the 

 tropical and subtropical seas of the world, except on the Pacific 

 coast of America. 



As in the case of the Masked Booby, an example taken " at sea 

 off the Cape of Good Hope " now preserved in the British Museum, 

 constitutes the only record of its occurrence within our limits. 



This Booby is well known on the Island of Ascension, and the 

 skins and eggs brought thence by Sir David Gill some years ago, 

 are now in the British Museum. 



Family III. FKEGATIDJE. 



The Frigate birds are of large size and powerful flight, resembling 

 in this respect the Birds of Prey.' They are oceanic in habit, and 

 nest only on remote oceanic islands. 



Anatomical characters are : cervical vertebrae fifteen in number ; 

 a large vomer present ; furculum anchylosed at its dorsal ends to 

 the coracoids, and at its ventral end to the keel of the sternum ; 

 nostrils not pervious ; ambiens and femorocaudal muscles present ; 

 syringeal muscles present ; skin slightly pneumatic. 



The single genus contains only two species closely allied to one 

 another. 



