THE CLICK BEETLES, 



701 



LeConte. — "Revision of the ElatericUe of the United States," in 

 Trans. Amer. Philos. Soc., X, 1853, 405-508. 



Horn. — "A Monograph of the Species of the Subfamilies Eucne- 

 minae, Cerophytinae and Perothopinas inhabiting the United 

 States," in Trans. Amer. Entom. Soc., XIII, 1886, 5-58. 



For convenience the family is first divided into subfamilies, and 

 these, in turn, into tribes and genera. Of the five subfamilies rec- 

 ognized, representatives of three have been taken in Indiana, while 

 those of a fourth perhaps occur. 



KEY TO INDIANA SUBFAMILIES OF ELATERIDiE. 



a. Hind coxae dilated into plates which cover in part or entirely the 

 thighs ; trochanters of middle and hind legs very small. 

 h. Labruin concealed; antennae somewhat distant from the eyes, their 

 insertion narrowing the front. 



Subfamily I. Eucnemtn.e, p. 701. 



hh. Labruin visible. 



c. Labrum free ; antennae arising near the eyes under the frontal mar- 

 gin. Subfamily II. Elaterin^, p. 713. 

 cc. Labrum transverse, connate with the front; ventral segments five; 

 claws serrate. Subfamily III. Perothopinje, p. 772. 

 aa. Hind coxae not dilated into plates ; trochanters of middle and hind legs 

 very long; labrum short, transverse, connate with the clypeus ; tarsal 

 claws serrate. Subfamily IV. Cerophytin^, p. 773. 



Subfamily I. EUCNEMINAE. 



Head convex, deflexed, and resting against the sternum in re- 

 pose ; labrum absent or very slightly visible ; antenna? inserted upon 

 the front at the inner extremity of transverse grooves ; prosternum 

 movable, but less so than in the Elaterina?, without a lobe in front. 

 The majority of the species are rare, and the larvae have a striking 

 resemblance to those of the family Buprestida?, both in form and 

 habits, being abruptly enlarged in front, and usually occurring in 

 wood which has just begun to decay. Representatives of twelve of 

 the 22 genera are known from Indiana, while those of four others 

 perhaps occur. 



KEY TO INDIANA GENERA OF EUCNEMINAE. 



a. Last joint of maxillary palpi acute ; prosternal sutures and side margin 

 parallel ; bases of antennae moderately distant. 

 h. Tibia? broad, compressed ; length 0-8 mm. I. Melasis. 



hh. Tibiae slender ; length 4-7 mm. II. Tharops. 



aa. Last joint of maxillary palpi dilated ; prosternal sutures and margin 

 converging; bases of antennae close together. 



