pronolal hypomeron 

 pronotum 



lateral margin of elytron 

 sublateral carinae 



epipleuron 

 etastemum 



trachea 



carina ol elytron 



tiind wing 



heart 



abdonninal tergite 



serrate margin 



. (tubercle) 



gonad 



spiracle (in pleuron ) 



malpighian tubule 



epidermis 

 abdominal sternite 



(cuticie) 

 ventral nerve cord 



apical tooth 



lateral lobe 

 prostheca 



Figs 3-7 Adult elmid beetle: 3- lateral aspect; 4- diagrammatic 

 cross section through abdomen; 5- mandible of Heterelmis 6- maxilla, 

 right side, ventral aspect, of Neocylloepus; 7- labium, ventral as- 

 pect, of Neoaylloepus. 



mounted in Hoyer's medium and examined promptly. By jiggling of the 

 cover glass with a needle, one can usually get the specimen into the 

 necessary position for observation (at times a dorsal view is needed, 

 at other times, a lateral or ventral view may be desired). Since 

 Hoyer's medium is soluble in either alcohol or water, the specimens may 

 be readily removed even after months on the slide. 



A formidable vocabulary has arisen for the description and classification 

 of beetles. This is not surprising, in view of the fact that they repre- 

 sent the largest order of plants or animals. Nor is it surprising that 

 some terms have been used in diverse ways or that a number of different 

 terms have been used for a particular structure. Figures 1-15 should 

 assist the reader not only in making use of the following keys but also 

 in understanding the more detailed references he may consult. These are 

 diagrams or simplified figures of representative dryopoid beetles, 

 illustrating the major morphological features and the terms most commonly 

 applied to them. The figures should be useful even though some of the 

 terms are not employed in the keys. It will be worthwhile to study Figs 

 1-15 with care before attempting to use the keys. These figures serve 

 as an illustrated glossary, though a standard form of glossary is appen- 

 ded (p. 73). 



