164 



ELEMENTARY ZOOLOGY 



labial 



labium j 



compound eye- 



mouth-parts 



palpi 

 head 



coxa 

 trochanler- 



femur-' 

 tibia 



tarsal segments 



~prothorax 

 -jnesothora 

 metathorax 



abdom 



FIG. 39. Ventral aspect of male great water-scavenger beetle, 



ffydrophilus sp 



