216 DIPTERA OF AUSTRALIA, 



little or no estimation by others. Those under the latter category 

 are mostly transient describers, who, in the majority of cases, 

 make the species they describe perfectly undeterminable through 

 their insufficient acquaintance with the peculiarities of even the 

 genus to which they j)ossihly correctly refer them, and their 

 ignorance of the systems previously elaborated by authors who 

 have perhaps, like Winnertz, devoted years of most careful study 

 in ascertaining the importance and unimportance of the structural 

 characters presented by the species. Consequently just those 

 ■peculiarities necessary to be pointed out for the correct identifi- 

 cation of a certain insect are often quite omitted, and what is 

 sometimes called the description of a species will apply equally 

 well to all the species in the genus, or even to those of allied 

 genera. 



Schiner in 1868 (Novara Exp. Dipt. p. 24) recognised sixteen 

 established genera as belonging to this family, not counting his 

 own genus, Telmatogeton, created in 1866. The known species of 

 the world were set down as numbering 669, of which 551 occur 

 in Europe, 93 in America, 5 in Africa, 13 in Asia, and 7 in 

 Australia (to which latter Geratopogon rhynchojjs, Sch., must be 

 added). As far as I can ascertain, a very inconsiderable number 

 of species have been described during the last twenty years, and 

 these principally belong to the genus Chironomus. About half 

 the known species are referred to the genus Chironomus (though 

 many of them should be removed to the genera subsequently 

 derived from it), and are of unlimited distribution ; but as far as 

 has been ascertained, it principally predominates in northern and 

 temperate latitudes. The species of Chironomtts and closely 

 allied genera now described from Australia constitute the 

 majority of the members of this group as far as its representa- 

 tives are known, but it is premature to generalise upon the 

 distribution of these or any of the other genera until a great 

 deal more collecting has been done, not only in the other 

 colonies, but also in the vicinity of Sydney. Judging by 

 the result of limited research the number of unknown species, 



