THE niSTER BEETLES. 601 



1142 (84(31). IIOLor^PTA fossu'lakis Say, .Jom-n. Phil. Acad. Nat Sci., V, 

 ISLT,, 47; ibid. II, i^Tl. 

 Itfsembles closely the iirecediug, diffei-ing only in the 

 striation of the elytra. The first stria is short, extending 

 not over a fourth of the elytra, the second still shorter and 

 the third merely a trace. Males with a deep pit near thej 

 front angles of thorax, this lacking in females. Length 7- 

 9.5 mm. (Fig. 230.) 



Sottthem half of State; frequent. April 6-June 

 27. Appears to be nmch more common in spring, j,. ^^ ^g 

 This and the preceding are very close and time will (Original.) 

 donbtless prove that they are the same, Say's name having priority. 



Tribe II. HISTRIXI. 



To this tribe belong a nnmber of genera, which live mainly in 

 excrements or beneath bark. They vary much in form and have the 

 mandibles capable of bei«ig applied to the front edge of the pro- 

 sternum so as to conceal the mouth. Between the prosternal lobe 

 and the prosternum proper is a suture, so that the former appears 

 to be a distinct piece. In a number of genera the lobe is very wide, 

 extending to the imder edge of the thorax and forming the floor of 

 a cavity -which holds the antennae when the beetle is in repose. 

 When so extended, the widened portion is called the "pectoral 

 plate. ' ' Six of the twelve known genera of the tribe are repre- 

 sented in Indiana, while a seventh probably occurs. 



KEY TO INDIANA GENERA OF HISTEINI. 



a. Antennal cavities beneath the front angles of the thorax, open in front, 

 but closed more or less completely beneath by the pectoral plate. * 

 h. Club of antenniE more or less oval, pubescent, and distinctly ringed 

 or annulate; thorax without a lobe <m the side. 

 c. Mandibles rather prominent, upper edge rounded; labrum trape- 

 zoidal; antennal club broadly oval; elytra distinctly striate. 



II. HiSTEB. 



ec. Mandibles retracted, upper ed,t,'e acute; labrum short, very trans- 

 verse. 

 (I. Form. ovate; elytra scarcely striate; prosternum broad, the lobe 

 short ; antennal club truncate. III. Tbibalcs. 



dd. Form more oblong; elytra distinctly striate; prosternum of mod- 

 erate width, the lobe distinct ; antennal club rounded. 



IV. Epierus. 



&6. Club of antennae obconieal. solid, glabrous ; thorax with a distinct 



lobe on each side ; clypeus truncate. V. Het^eeids. 



f/fl. Antennal cavities beneath the middle of the inflexed sides of the thorax. 



in front of the outer portion of the coxse, not closed beneath liy a 



pectoral plate. 



