A GUIDE TO THE STUDY OF BRITISH WATERBUGS. 205 



labels, one with the locality, the other with the name of the 

 insect ; and when specimens have been received from correspon- 

 dents, it is well to add a third bearing the name of the sender. 

 In my own collection, when I have been able to examine the 

 original type specimen of any species, and to compare with it 

 my own or other examples, I add a fourth label, " Compared 



with the Type in colln. by G. W. Kirkaldy." _ This is 



more useful perhaps in rare and little known exotic species. 



Note-books are necessary for the registration of species, both 

 those obtained from other workers and those collected by oneself, 

 with notes on habits, locality, &c. 



It will not be necessary to speak here of cabinets, store-boxes, 

 mite and mould preventives, as the treatment in this case will 

 not differ materially from that adopted for other insects. 



In concluding the hints on "Mounting," I would reiterate 

 "use long pins," "mount as soon as possible after capture," and 

 " label fully." 



One word as to measuring. It is the almost universal practice 

 among entomologists to employ the metrical system, and it will 

 be well for young collectors to familiarize themselves with it. 



Literature. 



The following are a few of the books and papers that should 

 prove useful to the British collector : — 



1. Saunders— ' Hemiptera-Heteroptera of the British Isles.' 

 (Beeves, 1892. 14s.). In this indispensable work, analytical 

 tables and short descriptions are given of all the species known 

 up to 1892. As the author does not adopt the almost universally 

 accepted "law of priority" in nomenclature, a short list of 

 necessary alterations will be given subsequently. 



2. Douglas and Scott — ' British Hemiptera-Heteroptera ' 

 (Ray Society, 1865. Obtainable from secondhand booksellers for 

 about 18s.). This work is out of date ; and, moreover, possesses 

 the disadvantage of being unprovided with analytical tables; 

 nevertheless, it is well worthy, from the excellence of the illu- 

 strations, of being added to the student's shelves. 



3. Dufour — ' Recherches anatoiniques . . . sur les Hemipteres ' 

 (Mem. Savants Etrang. a l'Acad. Sci. iv. pp. 129-462; 1833. 

 Obtainable from secondhand booksellers for about 16s.). These 

 researches deal with the anatomy and biology of a number of 

 species occurring in the British Isles. 



4. Miall— ' Natural History of Aquatic Insects.' (Macmillan, 

 1895. 6s.) Sixteen pages deal with waterbugs. 



The student will also, after mastering these works, find it 

 well to become acquainted with the papers dealing with the 

 waterbugs of the various European countries by Fieber, Stal, 

 J. Sahlberg, Puton, Horvath, &c. 



