CLASSIFICATION AND NOMENCLATtlRE. 23 



ever cau be given, iuasmuch as the characters which constitute it often 

 possess very different values in the different genera and families, not 

 only of insects, but of animals generally, and therefore the formation 

 of genera must necessarily be left to the judgment of the author. 



It is the natural tendency of the specialist* to attach undue value to 

 the minor subdivisions of his particular department, whilst he whose 

 studies take a wider range sees more forcibly the necessity of condensa- 

 tion and simplification. Much can be sai(^ upon both sides of this ques- 

 tion, but perhaps the argument may be condensed into a single sentence 

 by saying that, on the one hand, the minute subdivision of a natural 

 group tends to give definiteness and precision to our investigations, 

 whilst, on the other hand, the multiplication of genera or sub-geneia, 

 upon trivial characters, unnecessarily encumbers our nomenclature, and 

 diminishes the interest and importance which ought to attach to the 

 generic distinction. 



In writing the names of insects — and the same rule applies to all 

 other departments of natural history — it is the established custom to 

 write first tlie name of the genus, usually without the author's name 

 attached, and immediately following it the specific name, with the name 

 of the original describer, or an abbreviation of it, appended. As no 

 one can carry all the modern genera of insects in his memory, it is an 

 excellent practice, when space permits, to prefix the name of the older 

 and more comprehensive genus to which such species was formerly re- 

 ferred, and with which most entomologists may be presumed to be fa- 

 miliar. In this case the modern genus is included in a parenthesis, and 

 usually with the author's name attached. 



To illustrate by examples : The common rose-slug is the larva of a 

 little wasp-like insect, known scientifically as the Selandria rosw of 

 Harris. This species was first described by Dr. Harris, who gave to it 

 the specific name roscc, meaning of the rose. It belongs to the modern 

 genus l^clandria, which was founded by Dr. Leach, an English ento- 

 mologist. This genus is a subdivision of the old genus Teuthredo, of 

 Linnteus. The name written in full, therefore, will stand : 



Tenthredo (Selandria^ Leach^ rosai, Harris. 



Our fine large Polyphemus moth was originally described by Linna?us 

 under the name of Attaeus Polyphemus. It belongs to the modern genus 

 Telea, made by the German lepidopterist, Hiibner. Its name, there- 

 fore, expressed in the simplest manner, is Telea Polyphenms, Linn.; or 

 written in full — 



Attaeus {Telea, Hiibner^ Polyphemus, Linuneus. 



This is ordinarily all that is essential to be known, and any additional 

 synonyms or references should be placed in a subordinate position. 



