748 



FAMILY XXXVII. ELATERTDJE. 



d. Clypeus flat or slightly concave; thorax slightly wider at middle 

 than elytra, strongly narrowed in front ; length 14-17 mm. 



1415. FISSILIS. 



dd. Olypeus strongly concave; thorax not wider at middle than elytra; 

 length 15-17 mm. 1416. canadensis. 



a a. Hind angles of thorax with but one carina. 



e. Fourth joint of antennae at least one-third longer than third. 

 /. Size larger. 12.5 or more mm. ; form rather robust. 

 g. Surface of thorax sparsely and rather finely punctate, the sides 

 straight from base to near apex ; clypeus subangulate at apex ; 

 length 12.5-14 mm. 1417. sagittaeius. 



gg. Surface of thorax, at least on sides, coarsely and rather densely 

 punctured; sides more or less rounded toward apex; clypeus 

 broadly rounded ; elytral intervals coarsely and distinctly punc- 

 tate ; length 14-15 mm. 1418. difficilis. 

 f f. Size smaller, not over 12 mm. ; form usually much more slender. 

 li. Thorax very finely and so densely punctate as to make the sur- 

 face dull; pubescence short, erect; length 10-11 mm. 



OPACICOLLIS. 



hh. Thorax normally punctate, the punctures either much more 

 sparse or much coarser. 

 i. Surface closely pubescent with long gray prostrate hairs; ely- 

 tra but slightly narrowed from base to apex ; length 10- 

 11.5 mm. 1419. pilosus. 



it. Surface sparsely pubescent with much shorter hairs; elytra 

 (except in macer) distinctly narrowed behind the middle. 

 ./'. Carina? of hind angles very long, and close to margin ; third 

 joint of antennae one-half longer than second, the two to- 

 • gether slightly shorter than fourth : length 11 mm. 



1420. CAKINUS. 



jj. Carina? of hind angles not reaching middle of thorax ; third 

 joint more than one-half longer than second. 

 7c. Length not more than 9 mm. ; form very slender. 



1. Clypeus rounded in front, convex; thorax short, not 

 longer than wide. 1421. teapezoideus. 



//. Clypeus subtruncate, concave; thorax more slender, 

 longer than wide. 1422. pbasixus. 



kk. Length 10-12 mm. ; form more robust. 



m. Clypeus strongly concave; sides of thorax straight; ely- 

 tra parallel or nearly so. 1423. macer. 

 mm, Clypeus flat or subconvex ; sides of thorax more or less 

 rounded; elytra distinctly narrowing behind the mid- 

 dle. 



n. Dark reddish-brown or fuscous; disk of thorax coarse- 

 ly and rather sparsely punctate. 



1424. VERBEBANS. 



nn. Pale reddish-brown; disk of thorax very finely and 

 more sparsely punctate. 1425. angustatus. 



ee. Fourth joint of antenna? but little, if any. longer than third. 



