The more common sea-birds are the Sula variegate or guano-bird, a large gull called the Larus modestus, the Pelecanus thayus, and the Sterna Ynca, a beautiful tern with curved white feathers on each side of the head.
On the lakes there is a very handsome goose, with white body and dark-green wings shading into violet, called huachua, two kinds of ibis, a large gull (Larus serranus) frequenting the alpine lakes in flocks, flamingoes called parihuana, ducks and water-hens.
Of the genera recognized by him, Pagophila and Rhodostethia have but one species each, Rissa and Xenia two, while the rest belong to Larus.
We have then the genus Larus, which ornithologists have attempted most unsuccessfully to subdivide.
The largest species known is the Stercorarius catarrhactes of ornithologists - the "Skooi" or "Bonxie" of the Shetlanders, a bird in size equalling a herring-gull, Larus argentatus.
