406 Synopsis of the Birds 



Pouncing from the sky on flying fishes, and never missing 

 in the air ; unable to fish in water, from which they could 

 not rise again ; skim the surface, or lie suspended with their 

 wings raised over their back. Breed on trees on desert 

 shores, or on elevated rocks: eggs one or two. 



Chiefly tropical. Formed of but two species, of which 

 one is even doubtful. Analogous in form and habits to the 

 Accipitres, especially the Eagles, which they replace on the 

 sea.* 



858. Tachypetes aquilus, VieilJ. Purplish-black : orbits 

 black ; shaft of the outer tail feather white beneath. 



Adult, summer plumage ? head white. 



Young, part of the breast and belly white. 



Frigate, Tachypetes aquilus, Nob. Am. Orn. v. Grande 

 Fregate de Cayenne, Buff.pl. enl. 961- Pelecanus aquilus, 

 leucocephalus, et palmerstoni, Gm. Lath. Tachypetes aquila, 

 Vieill. Gal. des Ois. pi. 274. 



Inhabits the tropical seas, spreading somewhat in each 

 temperate zone : not uncommon during summer on the 

 coasts of the United States, as far north as South Carolina. 

 The changes of plumage in this species, are not yet well 

 knovn. 



79. SULA. 



Sula, Briss. Cuv. Temm. Ranz. Pelecanus, L. Gm. Lath, 

 Dysporus, III. Morus, (since Sula) Vieill. 



Bill longer than the head, cleft beyond the eyes, robust, 

 straight, conic-elongated, very stout at base, compressed, 

 mandibles subequal ; upper seamed each side, ridge distinct, 



* This analog)', observed by Linne, as is evident from bis specific name, 

 has lately been mistaken for affinity. 



