3i8 British Dragonfiies. 



examined. Should only a single nymph-case be obtained, 

 it may be mounted at the end of a thin strip of card- 

 board, placed at right angles to the long axis of the 

 body. The empty case is extremely light, and a very 

 small surface need be in contact with the card. The 

 spot chosen had better be about half-way down the 

 ventral surface of the abdomen, where nothing that is 

 likely to need examination is found. The pin and 

 label should be placed at the other end of the strip of 

 cardboard. If a good supply of nymphs is available, 

 some had better be preserved in one of the solutions 

 before the imagines emerge. The mounted n\'mphs may 

 be placed in the cabinet with the perfect Dragonflies, 

 or, if they seem to detract from the appearance of the 

 latter, they may be placed in a drawer by themselves, 

 which will allow of comparison with one another, a 

 connection quite as important as that between them- 

 selves and the perfect insects to which they give rise. 



