of the United States. 409 



concave, narrow, pervious, half closed by a membrane : 

 tongue very short. Head and throat wholly feathered, the 

 former depressed, moderate ; eyes rather large ; neck short ? 

 thick ; body moderate, rather plump. Feet very short ; tarsi 

 naked, shorter than the second toe : exterior elongated, mid- 

 dle longest ; outer edged exteriorly by a small membrane ; 

 hind toe one third the length of the middle one : connecting 

 membrane broad, full, entire : nails moderately curved, acute ; 

 middle with the inner edge entire. Wings long, tubercula- 

 ted ; first primary longest. Tail short, of twelve or fourteen 

 feathers ; middle one very narrow, much elongated. 



Female similar in color to the male, but much smaller. 

 Young differ greatly from the adult, changing repeatedly. 

 Moult twice a year. Plumage thick and close. Colors white. 



Keep in families, chiefly in remote aud desert islands, ap- 

 pearing at wonderful distances from the land. Excel in flight, 

 able to rest for a long time, and even sleep on the water. 

 Never dive, even partially. Hardly able to walk, alighting 

 on trees, or rocks, occasionally on the rigging of vessels. 

 Feed chiefly on the flying fishes abounding between the 

 tropics : seize them by skimming the surface of the water. 

 Build in hollow trees, or on inaccessible cliffs : eggs two : 

 young at first covered with very fine soft white down. 

 Sight keen. Remarkable in their appearance : sure indi- 

 cations of the torrid zone, not, however, of the proximity of 

 land. 



Tropical, spread all around the globe. Composed of but 

 three species, multiplied, owing to their changes. Related 

 to the Family Longipennes, especially the genus Sterna. 



361. Phaeton ^thkreus, L- White varied with black ; bill 

 red ; tail cuneiform, of fourteen feathers. 



Adult somewhat tinged with rose; long tail feathers red. 

 Tropic bird of Wilson's list. Buff. pi. enl. 979. ad. Id. 998. 

 young. Phaeton phoznicurns, Vieill % Gal. des Ois. pi. 279. ad. 



