48 Transactions. 



leading peculiarity which characterises all the orders, namely, 

 the deep insection which occurs between the fore part of the 

 body, or thorax, and the hinder part, or abdomen. Perhaps 

 one of the most conspicuous examples may be found in the 

 common wasp, where the insection is so conspicuously pro- 

 minent ; more so, perhaps, than in any other order of insects. 

 The fine distinct order of insects containing the moths and 

 the butterflies are known everywhere as the order Lepi- 

 doptera. This very descriptive title has been conferred on 

 the whole tribe of the Lepidoptera in consequence of the 

 minute scales with which their wings are all covered. It is 

 to these scales they are indebted for all their beautiful 

 colours and markings. When the scales are off the mem- 

 brane of the wings is perfectly smooth and transparent. 

 The Lepidoptera was divided by Linnaeus into three great 

 sections : first, the Diurna, being all those which fly by day, 

 which comprises all the butterflies ; secondly, the Nocturna, 

 or those which fly by night, which includes a large portion 

 of the moths ; thirdly, the Crepuscularia, which was in- 

 tended to comprise such as generally fly by evening, twilight, 

 or early dawn of morning. But this third division of Cre- 

 puscularia was soon found to be unworkable, and the time of 

 flight, as a general rule, was not a good basis of classification. 

 The more modern system of entomological classification is 

 much more correct, which comprises only two gi-and divi- 

 sions, founded on the only true basis of classification, namely, 

 anatomical distinctions. The first division embraces all 

 those having a small club-like enlargement at the ends of 

 the antennas, which comprises all the butterflies. In the 

 moths the antennce are sometimes smooth, sometimes 

 feathered, sometimes robust, sometimes long and slender. 

 The antennce of the males very frequently differ from those 

 of the females, but they are never clubbed liked the butter- 

 flies — ^the great family of the Oeometrida}, which is composed 

 of a group of insects that are in many respects very distinct 

 from the great family of the Noctuidoi. Nearly all the 



