REVIEWS. 
97 
study, possessing a vantage ground of the most favourable kind in the 
antecedent writings and the collection of Fallen, and aided by the dis¬ 
interested co-operation of all the Dipterists of the peninsula. Where can 
we hope for such a concurrence of propitious circumstances again! And, 
voluminous as that work has been rendered, may it not be a question 
whether the descriptions are satisfactory, after all ? Would it not have 
been more for the interest of science, if Zetterstedt had published a sepa¬ 
rate corpus descriptionum, which would have been of permanent utility to 
all students ; following this up with a proper Fauna of more manageable 
size. 
Of the legitimate additions that we have indicated, which would have 
added to the value of Mr. Walker’s book as a Fauna, we do not find much 
in it; nor have we any right to complain of this. Not near enough has 
been done to direct collectors to more ample information, or to induce a 
profounder study of the science. More discrimination in the choice of 
authorities, and more particularity in the . references to them, would have 
sufficed for that purpose, without any enlargement of the bulk. The too 
exclusive attention paid to the British species, in the characters of the 
families and genera, is ill adapted to communicate a general idea of the 
classification. 
After all the criticisms of them that we have been obliged to go into, we 
must repeat, before taking leave of these volumes, our cheerful attestation 
of their high scientific merit, in more than one respect. If the work has not 
fully satisfied us, considered as a Fauna; we can pronounce a much more 
favourable judgment on it as a sketch of the classification of the Diptera, 
so far as this has its representatives in the British islands. For the sake 
of science generally, and of the British Fauna in particular, we hope that 
the future labourers in the same field will regard this work of Mr. Walker’s 
in the light of a systematic essay, which requires but a slight supplement 
to make it complete; while, for the purposes of a Fauna, it would be 
rendered only more cumbrous and confused, by additions and corrections. 
One of the most useful labours a British Dipterist could undertake would 
be, to give more complete descriptions of Mr. Walker’s new species—while 
the originals can still be consulted—through some channel where they 
would be easily accessible to students generally. When that is done— 
and we trust it may be before long—there will be the materials for a really 
good British Fauna of this order ; and the more complete in itself this is 
made, independent of the book we have been reviewing, the better; as any 
other course would detract much from its utility. H. L. 
