THE GROUND BEETLES. 



141 



Tribe XIII. LEBIINI. 



Antennae slender, arising from beneath a slight frontal ridge, 

 the three basal joints usually glabrous. Head oval, constricted to 

 a neck or not. Mentum more or less emarginate, toothed or not ; 

 palpi variable, the terminal joint equal to or longer than the pre 

 ceding, the latter with two set* in front. Thorax variable in form, 

 sides distinctly margined and with a seta on each side and at basal 

 angle. Elytra truncate at tip, the margin acute, entire and nar- 

 rowly inflexed. Prosternum usually obtuse at tip ; hind coxae con- 

 tiguous. 



The following papers treat of the genera composing the tribe : 



Horn. — " Revision of the Species of Lebia of the United States" 

 in Trans, Amer. Ent. Soc, IV, 1872, 130-142. 



Horn. — "Synoptic Tables" of most of the genera, in Bull. 

 Brook. Ent. Soc, II, 1880, 86; IV, 1881, 39-44; 53-55. 



Horn.— ' Synopsis of the Species of the Tribe Lebiini ' ' in Trans. 

 Amer. Ent. Soc, X, 1882, 126-163. 



The tribe is a large one, embracing no less than 21 genera in the 

 United States fauna, Of these, 14 are represented in the collection 

 from Indiana, while another may occur. 



KEY TO INDIANA GENERA OF LEBIINI. 



a. Tibial spurs very long. 



b. Head not constricted behind the eyes ; tarsal claws in our species 



with fine, short teeth ; tibial spurs with fine teeth. 



XXXIX. TEtragonoderus. 

 &6. Head constricted ; tarsal claws with long teeth ; tibial spurs simple. 



Nemotarsus. 



aa. Tibial spurs short or at most moderate in length. 



c. Mandibles with distinct grooves on outer side. 



d. Head constricted behind the eyes. XL. Lebia. 



dd. Head not constricted. 



e. Labrum large, prominent, covering in great part the mandibles ; 

 antenna? with three basal joints glabrous ; elytra dark bluish- 

 green. XLI. Coptodera. 

 ee. Labrum moderate, not large. 



f. Tarsi slender, fourth joint entire. 

 p. Labial palpi slender ; color black or piceous. 

 h. Thorax truncate at base. 



i. Mentum not toothed ; claws of tarsi serrate ; length 6- 



7.5 mm. XLI I. Dromius. 



ii. Mentum toothed ; claws of tarsi simple ; smaller, not 



over 4 mm. XLIII. Apristus. 



hh. Thorax slightly lobed at base; claws of tarsi serrate; 

 length less than 4 mm. 

 j. Mentum not toothed. XLIV. Blechrus. 



