A GUIDE TO THE STUDY OF BRITISH WATERBUGS. 203 



Society, in order that the Fellows may have an opportunity of 

 judging whether flavidorsana is really petiverella or qucestionana. 



Folkestone : August, 1898. 



A GUIDE TO THE STUDY OF BRITISH WATERBUGS 

 (AQUATIC RHYNCHOTA). 



By G. W. Kirkaldy. 

 (Continued from p. 180.) 



Mounting. 



Until a few years ago the almost universal method of mounting 

 bugs and beetles consisted in gumming or glueing the ventral 

 surface of the insect on to a square or oblong piece of card, 

 sometimes with the legs carefully extended, but more often 

 cramped together under the body. Now, considering that very 

 important specific characters are furnished by the legs and 

 ventral surface of waterbugs, this method is evidently incon- 

 venient, and I am of the opinion that it is best to pin whenever 

 possible. 



Notonecta, Nepidee, Naucoridce, and the three larger species 

 of Gerris, should be transfixed through the scutellum by a fairly 

 stout "entomological" pin, about 35 millimeters (i.e. one inch 

 and three-eighths) long; for example, D. F. Tayler & Co.'s 

 No. 16. 



The specimens should be transfixed up to within about half 

 an inch from the head of the pin, and I think that a strong pin 

 is a great advantage, on account of retaining its position firmly 

 and steadily in the cork, and not suddenly bending at various 

 points, as is the custom of the very fine pins used by many 

 continental rhynchotists. After the lapse of years the general 

 condition of the insects mounted in the former manner will be 

 found to be much better than those mounted in the latter way. 



British collectors have long been notorious on account of 

 their predilection for short pins ; the advantages, on the other 

 hand, in favour of those I have previously mentioned are very 

 great; for instance, the danger of attack from Anthrenus, Atropos, 

 &c, is minimised almost to the vanishing point (although of 

 course the usual precautions must be adopted), and the space 

 for necessary labels is much increased. 



I cannot recommend black pins, — they are too soft and 

 pliant. Headless pins have often been advocated, but I think 

 that a small head is a great improvement. 



For Velia, Aepophilus, Acanthia, and the smaller species of 

 Gerris, the smallest and finest pin obtainable (about 14 milli- 



u2 



