LEPIDOl'TERA. SEMIDIURNA. 14,1 



their characters are enveloped in considerable obscurity, although 

 it is palpable that there is great diversity of structure amongst 

 them : — it is consequently an object of difficulty to subdivide them 

 satisfactorily, in proof of which it may be remarked, that every 

 modern author who has treated upon the group differs in the dia- 

 })Osition of the species in the respective genera*. 



From the preceding insects, the present group may be known 

 by the bulk and thinness of their wings, compared to the size of the 

 body, which is generally very slender : they fly early in the after- 

 noon and in the evening, or in the twilight, though some few may 

 be found throughout the night ; but the typical species fly in the 

 full blaze of sunshine, and when they alight elevate their wings 

 after the manner of the Papilionidte. 



There are evidently three families, readily distinguished by the 

 larvae, in this group, but in the imago stiite their differences are 

 jiot very easily characterized : they may probably be known by the 

 subjoined characters : 



fbrevi. yJf/rt- <;«- C baud falcate, (/.(/rcw geometrical :) 1. Geo.mktiud.k. 



Ilka: < 

 ^pleruinque falcatcC. {Larvce baud gco- 

 metricffi:) . . .2. Platyptekicidte. 



I^elongati, magni; aut quatuor. (Lflz-ycc folliculata;:) . 3. Pyralid^e. 



* It is no easy task to arrange at once (as in my Catalogue) all the known 

 insect inhabitants of a country, and to dispose them into modern genera, without 

 occasionally placing some few in erroneous locations, by including them in genera 

 to which they may eventually prove alien, as may be the case with some of the 

 insects hereafter placed, in accordance with my Catalogue, under the present 

 group, from the enormous extent of the subject rendering it manifestly im- 

 possible to examine every insect with the accuracy which the mere selector of 

 a few conspicuous species, annually, ought to exhibit: and in this work a loca- 

 tion must he found for all that have been discovered, not having the power of 

 capriciously omitting the discordant ones ; and it may be added, that it already 

 contains full descriptions, with localities, &c. of about 3000 species; and that, 

 from recent publications, it appears that not 10 of those omitted to be noticed 

 in these pages luere discovered previously to the appearance of the respective 

 genera to which they appertain. 



