THE DARKLING BEETLES. 



7. Pronotum with a sharp edge at sides, its base as wide 

 as elytra 8. 



Sides of pronotum more or less rounded and without 

 a sharp edge 10. 



8. Antennae thread-like 9. 



Antennae with long, flat processes folding like a fan 



(male) , or somewhat saw- toothed (female) 



Pelecotoma of the RHIPIPHORID^E (p. 393). 



9. Hind coxas with plates; head with vertex lobed or 

 ridged behind, so that, when extended, it rests on the 

 front edge of the pronotum; abdomen usually ending in a 

 pointed process MORDELLID.E (p. 385). 



Hind coxae without plates; length less than 

 .25 in Tribe Scraptiini of the MELANDRYID^E (p. 385). 



10. Pronotum narrower at base than elytra n. 



Pronotum as wide at base as elytra; the abdomen not 



ending in a spinous process; elytra usually shorter than 

 abdomen and narrowed behind; antennae comb-like in 



males, frequently saw- toothed in females 



RHIPIPHORID^E (p. 393). 



11. Hind coxae not prominent; tarsal claws simple; 

 antennae thread-like and simple; head with an abrupt, 

 narrow neck; length less than .5 in., usually less than 

 .2 in ANTHICIDJE (p. 386). 



Hind coxae large, prominent 12. 



12. Tarsal claws simple; head horizontal; antennae 

 usually branched in male, saw-toothed in female; next to 

 last tarsal joints very broad . . . . PYROCHROID^E (p. 386). 



Tarsal claws cleft or toothed; front vertical; at least 

 .25 in. long MELOID^E (p. 387). 



TENEBRIONID^: 



These are the Darkling Beetles. There are many 

 species in the Southwest, where they occur like Carabidae, 

 but they are by no means lacking in the East: New Jersey, 

 for example, having more than sixty species. The eastern 

 species are not usually found under stones, as are those 

 in arid regions, but in dead wood, fungi, and dry vegetable 

 products. The western Pinacate (Eleodes), "the bug 

 that stands on his head," is a member of this family. 



