labial palp -- jointed lateral appendage of the labium (Figs 2, 7, 15). 



labium -- lower lip formed from fused second maxillae (Figs 2, 7, 13, 15). 



labrum -- upper lip, attached basal ly to clypeus and covering bases of 

 mandibles (Figs 2, 3) . 



lamellate antenna -- one with a number of terminal segments that are 

 flattened and usually appressible like the pages of a book (Fig. 92). 



lotia -- with moving water, either wave-washed or flowing. 



maculate -- with spots (maculae) . 



mandible -- lateral jaw (Figs 2, 3, 5). 



maxilla -- lateral mouth part between mandible and labium (Figs 6, 13, 

 14). 



maxillary palp -- jointed appendage of maxilla (Figs 2, 3, 6, 14); 

 often the most conspicuous mouthpart on the intact specimen. 



mesopleuron -- pleuron of mesothorax. 



mesostenmum -- sternum of mesothorax (Figs 2, 13) . 



mesothorax -- middle segment of thorax; to it are attached the second 

 or middle pair of legs and, in adults, the elytra. 



metapleuron -- pleuron of metathorax. 



metastemum -- sternum of metathorax (Figs 2, 13) . 



metathorax -- third segment of thorax; to it are attached the third 

 or hind pair of legs and, in adults, the flight wings. 



moniliform antenna -- one with joints or segments like rather uniform 

 globular beads. 



ocellus (plural, ocelli') --a simple eye or eyespot. 



oahreous or ochraceous -- brownish yellow. 



operculum -- trapdoor- like ventral cover of gill chamber on last ad- 

 dominal segment of larva (Fig. 13). 



ovipositor -- sclerotized parts of female genitalia (usually hemistern- 

 ites) adapted for insertion of eggs into the substrate (e.g., in Helichus, 

 Figs 95, 101, 102). 



paramere -- lateral lobe of male genitalia, attached to basal piece and 

 enclosing penis (Fig. 10). 



73 



