23 (22) Second segment of antenna more than twice as long as 



first; prosternum with anterior suture obliterated; 

 no suture extending from procoxal cavity to lateral 

 margin of pronotum (Figs 163, 164): Ordobrevia 



Second segment of antenna less than twice as long as first; 

 prosternum with anterior median suture; suture from pro- 

 coxal cavity to lateral margin may or may not be visible. 24 



24 (23) Suture from procoxal cavity to lateral margin distinct; 



large and rather flattened, commonly well over 1 mm 

 wide; our species usually relatively smooth, black, 

 and rather shiny (Figs 165, 166) : Elsianus 



Suture from procoxal cavity to lateral margin indistinct 

 or absent; body more convex and elongate, smaller, not 

 more than about 1 mm wide; cuticle more granular in ap- 

 pearance, from pale tan to dark brown, not shiny (Figs 

 167, 168) : Stenelmis 



Figs 165-168 Larva of Elsianus texanus: 165- dorsal aspect; 

 166- ventral aspect. Larva of Stenelmis sp.: 167- dorsal aspect; 

 168- ventral aspect. 



25 (16) Postpleurite composed of 1 part (Fig. 13) 26 



Postpleurite composed of 2 parts (Fig. 177) 27 



26 (25) Body robust, broad, subtriangular in cross section; with 



spatulate spines along lateral margins and mid-dorsal 

 line (Figs 169, 170): Ampumixis 



Body long and slender, hemicylindrical; without prominent 



clusters of spines (Figs 171, 172): Cleptelmis 



27 (25) Mesopleuron composed of 1 part (Fig. 177) 

 Mesopleuron composed of 2 parts (Fig. 179) 



28 

 29 



62 



