124 COLLECTION AND PRESERVATION C^ INSECTS. 



Greasiness is a constant cause of trouble with insects, 

 particularly moths. Commencing in the body, it gradually 

 spreads until the whole moth looks as though it had been 

 dipped in oil ; from the insects the oil runs down on the 

 drawer below it, soiling the paper, and spoiling the ap- 

 pearance of the collection. No preventive to this is known, 

 but a greasy insect may be restored by immersing it in 

 naphtha, or essential oil of petroleum, and allowing the 

 oil to evaporate before the insect is returned to its place. 



Of Entomological Books. As the author intends this 

 for an introductory work on Entomology, and has done his 

 best to make it as complete as he was able, it would be but 

 a poor compliment to his readers, after giving them so 

 much trouble, were he to tell them of the necessity of 

 buying other introductions. Works descriptive of species, 

 will, however, be found highly essential, and the author 

 will give a list of all the British ones with which he is ac- 

 quainted, and such foreign ones as he considers to be pecu- 

 liarly useful ; he will arrange the books in the same order 

 in which insects are classified at page 76. 



Lepidoptera. 1. British Lepidoptera ( c Lepidoptera Bri- 

 tannica'), by Adrian Hardy Haworth, 1803, et seq., being 

 published in four parts. One volume, pp. 586, without 

 plates. This work is written in Latin ; it contains concise 

 and accurate descriptions of the British Lepidoptera, 

 known at the time the author wrote. 2. i Illustrations of 

 British Entomology,' Part Haustellata, by James Francis 

 Stephens. Four volumes, with numerous plates. This 

 work is written in English ; it contains descriptions of 

 all the known British Lepidoptera. 3. ( Conspectus of But- 

 terflies and Moths,' by James Rennie. One volume, no 

 plates. This work is written in English, and contains 

 descriptions of nearly all the British Lepidoptera. 



