Ixvl 
Oleria . . . Upper wings twice banded. 
Thyridia . . . Both wings banded. 
Such a mode of defining genera, although it has the merit of 
being simple and symmetrical, is undoubtedly superficial ; and it 
can only be by the purest accident that a group so characterised 
can correspond in extent to any real genus. It is therefore 
not surprising that two of these four Hiibnerian groups of species 
do not constitute modern genera; yet, because one of the rejected 
names, Oleria, has been applied by Mr. Bates to an allied genus 
characterised by him, Mr. Kirby thinks it necessary to give it a 
new name, because it does not correspond to the Oleria of 
Hiibner, again breaking the British Association law. In Mr. 
Kirby's own work, we find Hiibner’s condemnation in almost 
every page, in the utter want of agreement between his groups 
and modern genera. ‘The modern restricted genus Heliconius, for 
instance, contains species belonging to seven Hiibnerian genera ; 
Pieris comprises five, and Thecla twelve of these hap-hazard 
sroups; while, in other cases, the species comprising Hiibner’s 
groups are divided among several quite unrelated modern 
genera. 
Now here, it seems to me, the case is very strong against the 
practice of those who, like Mr. Kirby, advocate the adoption of 
Hiibner’s generic names. It is not that those who hold opposite 
views seek to annul or over-ride the law of priority by any self- 
created law, or by individual opinion; but it is a case in which 
there has been hitherto almost a universal agreement, fully 
supported by the tenor of the British Association Rules, that the 
names sought to be reinstated rank as mere catalogue names for 
want of proper definition, and should, therefore, never be quoted. 
The idea of justice to the first namer or describer of a species is 
sometimes appealed to; but the law of priority is founded on 
no such expressed idea, but rather on the universal practice of 
mankind, which always upholds stability of nomenclature, and 
requires cogent reasons of convenience or beauty to sanction an 
alteration. Intelligible language is wholly founded on stability 
of nomenclature, and we should soon cease to be able to understand 
each other’s speech, if the practice of altering all names we 
thought we could improve upon, became general. It was because 
this practice of reckless alteration of names had become so prevalent 
among naturalists, that it was found necessary to declare that 
