CLASSIFICATION. 91 
species had a separate name, but in 1766 Linnzeus introduced 
the binomial system of nomenclature, by which each species 
of a genus had the same generic name, while each was 
distinguished by its own particular specific name in addition. 
Owing to the number of naturalists at work in different 
parts of the world it constantly happens that a species gets 
two or more names. When these errors are detected the 
first published name is always taken as the true name, and 
the others are called synonyms. Often again a species may 
be referred to a wrong genus, and when this is corrected the 
incorrect name stands as a synonym. In order to obviate 
uncertainty as much as possible, it is usual to write the 
name of the author after the name that he used for any 
particular species, whether it was the true name or a 
synonym. For example the little garden warbler, or riro-riro, 
was first described by Quoy and Gaimard, the naturalists of 
the French Astrolabe Expedition, under the name of Curruca 
igata. Subsequently it was described in the zoology of the 
voyage of the Erebus and Terror as Gerygone flaviventris, 
Gerygone being the generic name applied by Mr. Gould to a 
small group of Australian birds. The same bird was again 
described by Pelzeln in the zoology of the voyage of the 
Novara as Gerygone aucklandica. In 1865 Dr. Buller 
described, under the name of Gerygone assymilis, a bird 
which he thought to be distinct from G. flaviventris, but 
which all ornithologists now think to be the same; and 
lastly, Mr. Sharpe, of the British Museum, found that our 
bird had not been correctly placed in the genus Gerygone, 
but, together with some other birds from Australia, New 
Guinea, and the neighbouring islands, belonged to a distinet 
genus, which he called Pseudogerygone ; so that the correct 
name of our warbler is Psewdogerygone agate, and the 
synonymy stands thus :-— 
