6 
INTRODUCTION. 
south-western portions of England and Ireland, and with a profusion of endemic 
modifications of its own (hearing witness to the engorgement of this ancient tract 
with centres of radiation created expressly for itself;, whilst geology proclaims the 
fact that subsidences on a stupendous scale have taken place, by which means the 
ocean groups were constituted; we seem to trace out on every side records of the 
past, and to catch the glimpses as it were of a veritable Atlantis from beneath the 
waves of time,—being well nigh tempted to inquire, 
“ And thou, fairest Isle 
In the daylight’s smile, 
Hast thou sunk in the boiling ocean, 
While beyond thy strand 
Rose a mightier land 
From the wave in alternate motion? 
“ Are the isles that stud 
The Atlantic flood 
But the peaks of thy tallest mountains, 
While repose below 
The great waters’ flow 
Thy towns and thy towers and fountains ? 
“ Have the ocean powers 
Made their quiet bowers 
In thy fanes and thy dim recesses ? 
Or, in haunts of thine 
Do the sea-maids twine 
Coral wreaths for their dewy tresses ? 
“ But we know not where, 
’Neath the desert air, 
To look for the pleasant places 
Of the youth of Time, 
Whose austerer prime 
The haunts of his childhood effaces.” 
Regarding the arrangement which I have adopted, I would especially advert to 
the great assistance which I have derived from Mr. Westwood’s admirable Intro¬ 
duction to the Modern Classification of Insects, —a work the merit of which it is 
difficult to overrate, and far surpassing every other in our own country (if not 
elsewhere also), in a systematic point of view, for the sound impressions which it 
conveys, and for the masterly manner in which the subject has been treated as a 
whole. It is a comparatively easy task to single out any one family or depart¬ 
ment, and to propound new doctrines on the collocation, inter se, of the various 
fragments which unite in composing it; but to weigh the problem m extenso, to 
balance the difficulties of conflicting methods from beginning to end, and to extract 
