4 The Genera and Species of Mallophaga 
a historical research of some magnitude, as my Bibliography will show, 
and one which I could not hope to have carried out in Australia. This 
examination has brought to light a considerable amount of neglected 
literature, and doubtless there is more still awaiting discovery. In 
dealing with it, I have endeavoured to do justice to some forgotten 
workers, and I hope that systematists will remember this point of view 
when they chafe at the disappearance of a few well-known names. 
So much for my justification! As to the plan of the present work, 
I have aimed, in the first place, at economising space. I publish my 
decisions on questions of nomenclature, without much of the argument 
upon which they are based. At a later date I may have an opportunity 
of discussing some of these decisions in greater detail. In all questions 
of nomenclature I have acted rigidly upon the International Code and 
upon the recommendations which accompany it, because I see no other 
way of achieving finality. 
The subject-matter is divided into eight parts, upon some of which 
I wish to give a little information : 
(i) General Introduction. 
(ii) List of species of Mallophaga included in the genera Pediculus 
Linn., Ricinus Degeer, and Nirmus Hermann. The reasons for making 
this a separate list are sufficiently set forth in the introductory note to 
the list itself. Each of these genera stood to include all known Mallo- 
phaga, and they must be regarded as equivalent. The names included 
in this list are thus all those used for Mallophaga prior to the introduction 
of Nitzsch's classification. All the names which I have been able to 
connect with a modern genus have been carried over to the main list, 
whether the species be recognisable or not. At the end of the section I 
give a list of the names which I have not been able to carry over, names 
which I am obliged to discard at this stage. * 
(iii) List of gerieric and subgeneric names, valid and invalid, used 
for Mallophaga. In this list, as in the list of species, no distinction has 
been made between genera and subgenera. The cause of invalidity is 
briefly indicated for each genus which is not held valid, excepting only 
a few that have not previously won a general recognition ; and in a few 
instances a reference is given to further discussions of the point involved. 
The genotype is indicated for both valid and invalid genera. Taschen- 
berg's subgenera, here treated as invalid, will undoubtedly have to 
come into general use. I have preferred not to introduce them at 
present for the reason already referred to, namely that it is advisable 
to clear up as far as possible all questions of nomenclature before 
breaking up the existing unwieldy genera. For the same reason I have 
