LARIDJS. 265 



sand. The nest is formed of a considerable quantity of sea- 

 weed and dried grass, and the egg (for only one is laid) is 

 originally white, though it soon becomes soiled. 



LAEHLE. GULLS. 



We have now arrived at the last family of the Natatorial 

 Birds, comprising the Gulls, abundant around our coasts ; 

 the Skuas, nearly allied to these, but more powerful and 

 courageous; the Terns, or Sea-swallows, which skim with 

 great rapidity along the water, skilfully raising from its 

 surface the small fishes and mollusks on which they feed, 

 and to obtain which they often plunge ; the Petrels, which 

 have derived their name (a diminutive of Peter), from their 

 peculiar motion on the surface of the water, which gives 

 them the appearance of walking on it, and in this the action 

 of the' wings upon the water assists them. To this family 

 also belongs the Albatross, the largest of aquatic birds. It 

 is nearly allied to the Petrel, which it resembles also in 

 its manner of treading the waves; it does not, however, 

 visit the northern parts of the Atlantic. We shall com- 

 mence our descriptive notices of the family with the Petrels, 

 of which the British species are classed under three genera. 



