THE CLICK BEETLES. 



707 



half; median impression distinct on basal third, a small fovea each side 

 of scutellum on basal margin. Elytra distinctly striate, intervals slightly 

 convex, punctuation dense, finer than on the thorax ; epipleura flat, roughly 

 punctate. Length 11-16 mm. 



Wells County; rare. July 14. Collected by E. B. Williamson. 

 Our largest species of the subfamily. 



Adelothyreus dejeani Bon v., elongate, slender, piceous, was de- 

 scribed from Maryland, and has been recorded from near Cin- 

 cinnati. 



VII. Microrhagus Esch. 1836. (Gr., "small + fissure.") 



Small elongate beetles having the body sparsely clothed with 

 short yellowish or brownish pubescence ; antennas at least one half 

 as long as body, second joint small, third nearly as long as the next 

 two, 4 to 10 serrate, sometimes pectinate in the male; antennal 

 grooves entire, located near the middle of under side of thorax. 

 Nine species are known from North America, five of which have 

 been taken in Indiana, while two others perhaps occur. They live 

 on dead timber, where they are to be found running about in the 

 sunshine or resting in crevices during cloudy or stormy weather. 

 The "posterior supplementary carina" mentioned in the key to spe- 

 cies is a raised line beginning at the tip of the hind angles of thorax 

 beneath, and extending forward more or less sinuously. 



KEY TO INDIANA SPECIES OF MICROEHAGUS. 



a. Hind coxal plates parallel, not dilated near the coxse; posterior sup- 

 plementary carina nearly entire. 

 6: Presternum prolonged and acute at tip; outer carina of antennal 

 groove obliterated behind the middle; elytra usually reddish at 



baSe - 1335. HUMEEALIS. 



66. Presternum obtuse at tip; outer carina of antennal groove entire; 

 elytra uniform black. im bonvouloiee 



aa. Hind coxal plates dilated near the coxse, narrow on the outer side. 

 c. Thorax with a fine raised line beginning on the apical margin near 

 front angles, and extending obliquely backward, but not reaching 

 the middle; antennas of male not pectinate. 

 d. Posterior supplementary carina very short; outer carina of an- 

 tennal groove much abbreviated behind; disk of thorax not im- 

 pressed at middle. 1337. impeefectus. 

 dd. Posterior carina extending at least to the middle of thorax, some- 

 times longer. 



e. Episterna of metathorax very narrow in front, broader behind. 

 f. Thorax without a carina in front of scutellum, the median 

 line impressed on basal half. subsinuatus. 



