460 NATATORES. 



spotted with blackish -grey. Upper plumage of nearly 

 a uniform clove-brown, the triangular spots upon the 

 tips of the feathers becoming less distinct, or entirely 

 disappearing. Under plumage becoming whiter. 

 Third year. The white increasing over all the body. The long scapu- 

 lars and tertials remaining black, or spotted with black- 

 ish-grey. The head beginning to acquire the sienna- 

 yellow tinge. 



The plumage of the fourth year is described above as the 

 adult Bird. 



FAMILY V. LARID^l. 



THE Laridae, which form the fifth family of the Order, 

 and thus complete the circle of the Natatores, are dis- 

 tinguished from the preceding division by the form of the feet, 

 which are never syndactyle, that is, with all the four toes 

 connected by a continuous membrane. The hind toe, in such 

 species as have one, is free and articulated on the back part 

 of the tarsus ; but in some it is either totally wanting or re- 

 presented by a nail or short claw. The wings of all the 

 members of this family are of great length, and they conse- 

 quently possess a power of long-continued flight, surpassed 

 perhaps by none of the feathered race. In them the bill is 

 either strait and pointed, as that of the Terns (genus Sterna), 

 or with a hooked tip, as in the gulls (genus Larus), Petrels 

 (G. procellaria), and other nearly allied genera. Most of 

 them subsist upon fish, and other marine matter, either in a 

 living state, or when cast ashore, or floating upon the sur- 

 face of the sea. Some are, however, in the habit of daily 

 frequenting the interior of the country, and feeding upon 

 earth-worms, slugs, insects, and other animal matter. They 

 are all birds of rapid digestion, and consequently of vora- 

 cious appetite. Many species are accustomed to repose upon 

 the water, where, from the bulk and closeness of their plum- 



