VI PREFACE. 



these parts forming a continuous trunk. The Hymenoptera sessiliventres are the saw- 

 flies, the Hymenoptera pedmiculata are all the rest. The Dipt era sessilirentrcs are the 

 crane-flies and gnats ; the Diptera pedunculata are all the rest. 



Those who have made entomology their study will know that these divisions are 

 unequal, in each instance one group being much more comprehensive than the other. 

 This is the case in British Lepidoptera, in which the Sessile-bodied Lepidoptera, or 

 Moths, outnumber ths Pedunculated Lepidoptera, or Butterflies, as thirty to one; 

 indeed, the number of moths inhabiting Britain has been ascertained to be more than 

 eighteen hundred and fifty, and, when collectors have the assistance of popular works, 

 it may reasonably be expected to reach two thousand ; for it is most evident that 

 nothing promotes the discovery of new objects so effectually as a reliable and faithful 

 guide to a knowledge of those which have been already ascertained. 



These two thousand moths were arranged by the illustrious Linnceus under two 

 heads, Sphinx and Phalcena; and the equally illustrious Latreille adopted these 

 divisions, merely altering the names, and calling the former Crepuscularia and the 

 latter Nocturna. Boisduval subsequently united these two groups under the name of 

 Hetcroccra, implying the diversity of form in their antennco, and at the same time gave 

 the name of Club-horned (in science Rhopalocerd} to the Butterflies. There is, how- 

 ever, no real or natural distinction to be found between Sphinges and Phalcence, and 

 therefore entomologists are now agreed in entirely abandoning groups which they 

 cannot distinguish much less define, the only difference being in the name ; the 

 terms Noctiirna, Ileterocera, Sessiliventres, and Moths, being always applied to the 

 same group of insects, and all these terms including both the Linnean genera, 

 Sphinx and Phalcena. 



The divison of the larger moths is still very incomplete, and must be considered as 

 requiring improvement. The great groups now stand as Nocturnes, Geometers, 

 Cuspidates, and Noctuas : three of these groups appear to be well defined and natural ; 

 the first, Nocturnes, is heterogeneous and far too comprehensive. So far back as the 

 year 1832 I ventured to propose a further subdivision of the Nocturnes, the merits of 

 which division, if merits there be, were entirely forestalled by Messrs. Denis and 

 Schiffenniiller, two Austrian officers who, in 1776, published an anonymous work on 

 the Lepidoptera found in the neighbourhood of Vienna, and who employed the 

 differences of the caterpillar in subdividing this difficult group, adopting as their motto, 

 " One eye to the caterpillar and another to the perfect insect." Their divisions are, 

 however, mainly dependant on the caterpillar and are strictly natural. 



Notwithstanding these and other improvements made from time to time, as our 

 knowledge of the preparatory states has progressed, no entomologist competent to 

 form an opinion will venture to say that we have arrived at anything approaching 

 perfection in our arrangements. Although a century has been spent in our search 

 after truth in this matter, we are still nothing more than students, and when we 

 attempt to teach, as in the present instance, we are, alas ! too apt to cay what must be 

 again unsaid, too apt. to write what must be again unwritten. Let us work and hope. 



