208 APPENDICES. 



hardens the specimens. Alcohol {Go per cent.) preserves these 

 insects well, without hardening them too much, but, after some 

 time, bleaches the colours ; it also distends the body, so that 

 the segments of the abdomen tend to become detached. 



For dry presex'ving, the fresh insects may be pinned or staged 

 and placed directly into the cabinet. In larger specimens the pin 

 is generally driven through one of the elytra ; long pins are pre- 

 ferable to short ones, in order to allow space for labels beneath. 

 Small specimens may be attached with fine silver or nickel pins 

 to a stage of pith or card, which in its turn is held by a strong 

 long pin which carries the labels. 



Tt is necessary to arrange them on the pins or stages so that 

 the ventral surface may be examined, ou account of the important 

 characters afforded by the sternal plates and ventral surface of 

 the anal region. 



Dry earwigs are among the most fragile of insects, the heavy 

 abdomen constantly tending to fall off. Very frequently the 

 forceps and last dorsal segment fall olF together ; in such cases, 

 care must be exercised in repairing them, as it is quite common 

 in Museums to see the forceps and last dorsal segment cemented 

 on upside down. Serville, indeed, founded a genus upon such a 

 specimen. 



It is iuaportant that the antennae and legs be extended to permit 

 easy examination of these important organs. 



Every possible information should of course be given on the 

 labels which should be attached to each specimen. 



For packing, it is best to keep the specimens in little tubes of 

 alcohol ; the delicate organs nearly always break off when they 

 are packed in papers like butterflies. 



Finally, the general principles which experience teaches in 

 dealing with other insects, such as Coleoptera or Ehynchota, 

 apply equally well to Dermaptera. 



B. 



Authors referred to and their Abbreviation. 



Annandale, Ur. jS". 

 Baer, G. A. 



Bolivar, Dr. Ignacio. Bol. 



Borelli, Dr. Alfredo. Bor. 



Borg, Hjalmar. 



Bonnans, A. de. Bonn. 



Brunner von Wattenwyl, Dr. Hofrath Iv. Br. 



