ELATERIDAE. 33 



a 1, Forehead with a distinct transverse 

 ridge. 



Tarsi strong, usually somewhat dilated. Athous, Esch. 



b 1, Forehead not ridged. 



A 2, Posterior coxae not much di- 

 lated and simple. 



Tarsi rather long and thin, rather bristly. 



Corymhites, Latr. 



H 2. Posterior coxae rather broad, 

 toothed behind. 



Tarsi rather long, bristly. Ludius, Latr. 



H &. Lower part of forehead and labrum 

 much deflexed, mouth on or nearly on under 

 surface of head. 



A 1, Sides of thorax blunt, marginal line 

 bent on to under surface in front. 



Antennae sawlike ; seams beneath thorax double, form- 

 ing traces of antennal grooves in front. Agriotes, Esch. 



-B 1, Sides of thorax sharp, bordered. 



a 1. Posterior coxae scarcely narrowed 

 outward. 



Antennae strongly sawlike, first joint moderately long, 

 only slightly thickened, second and third small, about 

 equal; seams beneath thorax double, forming traces of 

 antennal grooves in front. Sericosomus, Eedt. 



h 1. Posterior coxae considerably nar- 

 rowed outward. 



Antennae almost threadlike, second joint oblong, rather 

 longer than third ; seams beneath thorax double, interstice 

 not deep in front. Dolopius, Esch. 



jB J5. Third tarsal joint with a large membranous 

 appendage beneath, covering under-side of the 

 very small fourth joint. 



Labrum and mouth inflexed on to lower surface of head ; 

 under-side of thorax with traces of grooves for reception of 

 antennae ; tarsal claws comblike on inner-side. 



Ctenonychus, Steph. 



2. Last joint of maxillary palpi ovate, pointed. 



VOL. II, P 



