284 



FAMILY VIII. SILPHIME. 



Thorax oue-balf wider than long, sides feebly curved, hind angles obtusely 

 rounded; disk coarsely and very densely punctate. Elytra as wide at base 

 as thorax, thence feebly tapering to apex, sides nearly straight ; disk dense- 

 ly, finely and rather roughly punctate. Male with three joints of front 

 tarsi broadly dilated, middle tibiae strongly curved, hind ones straight. 

 Length 2.5 mm. 



Clark and Posey counties ; scarce. April 21-May 6. Taken by 

 sifting. 



Tribe IV. ANISOTOMINI. 



This tribe comprises species of small size, having the body oval, 

 convex, sometimes capable of being contracted into a hemispherical 

 ball ; front coxae conical, contiguous, prominent, with trochantin, 

 the coxal cavities narrowly closed behind; hind coxse contiguous; 

 abdomen with six segments. They live for the most part either in 

 decomposing fungi or under the bark of dead trees. Seven genera 

 are known to be represented in Indiana, while two others may 

 occur. 



KEY TO INDIANA GENERA OF ANISOTOMINI. 



a. Head without antennal grooves beneath. 



ij. Hind tarsi five-jointed ; meso sternum not carinate ; antennal club five- 

 jointed. Hydnobius. 

 hl>. Hind tarsi with less than five joints ; mesosternum carinate. 



c. Antennal club five-jointed ; length 2.5-4 mm. VIII. Anisotoma. 

 cc. Antennal club three- jointed, elongate, loose ; smaller, not over 2 

 mm. ; elytra with fine transverse wrinkles. IX. Colenis. 



aa. Head with distinctly limited antennal grooves. 

 (1. Antennal club more than three-jointed. 



c. Antennal club five-jointed, elongate. (Fig. 4, No. 6.) 



f. Form broadly oval or hemispherical, convex ; frontal suture well 

 marked ; tarsi unlike in the sexes, presternum short in front 

 of coxae. X. Liodes. 



ff. Form oblong-elliptical, subdepressed ; frontal suture wholly lack- 

 ing ; presternum long before the coxae. XL Stetholiodes. 

 ee. Antennal club four-jointed ; number of tarsal joints the same in 

 both sexes. XII. Cyrtusa. 



del. Antennal club three-jointed ; tarsi unlike in the sexes. 



(/. Antennae ten-jointed. Isoplastus. 

 gg. Antennae eleven-jointed. 



Ji. Hind tarsi four-jointed; mesosternum not carinate between the 

 middle coxae; body strongly contractile. 



XIII. Agathidium. 

 lilt. Hind tarsi three-jointed ; mesosternum strongly carinate. 



XIV. Aglyptus. 



