(U)2 FAMl^^■ xxviii. — THO(;()srrii).K. 



The name of the typical genus, Trogoslta, derived from two 

 Greek words meaning "to gnaw" and "corn or grain," was given a 

 connnon European species which occurs in great numbers in worm- 

 infested granaries. Eecent observations, however, go to show that 

 its larva3 probably live upon the larvje of more injurious insects 

 which do the real damage to the grain. The larvte of the members 

 of the principal genus, Trnehroides, are whitish fattened grubs with 

 a pair of l)lack spots on the top oF each of the first three segments, 

 and with the last seginciil ending in two horny [)()ints. That of T. 

 corticaria was observed by Le Uaron to feed u[)on the larva; of the 

 coddling moth. 



The only paper treating of the family is that of 



Horn. — "Monograph of the Species of Trogosita {Tencbroidcs) 

 Inhabiting the United States," i)i Proc. Phil. Acad. Nat. Sci., 



1862, 82-88. 



It embodies but one of the nine genera among which the 30 or 

 more known species from North An)erica are at present distributed. 

 Three of these genera are known to be represented in Indiana, while 

 members of four others may occur. 



KEY TO INDIANA GENERA OF TROGOSITID.E. 



(t. Form elongate, margins not tlatteued ; head relatively large, eyes not 

 prominent; front eoxal cavities closed. 

 h. Eyes rounded. Nemosoma. 



?>^. Eyes transverse. 



c. Tibiae with spines; form cylindrical. I. Alindria. 



cc. TibijB without spines. 



d. Thorax truncate at apex, the side margin bent downward at mid- 

 dle. Trogosita. 

 (Id. Thorax emarginate at apex, the side margin not bent downward. 



II. Tenebroides. 

 aa. Form oval, margins flattened ; head small, eyes prominent ; mentum 

 transverse, emarginate ; front coxal cavities open behind, except in 

 Calitys. 

 c. Mentum transverse, emarginate; antenual grooves feeble. 



f. Front tibife with terminal hook. Peltis. 



//. Front tibiae without terminal hook. 



g. Front coxal cavities closed. Calitys. 



gg. Front coxal cavities open behind. III. Grynocharis. 



ee. Mentum minute, oval; antenual grooves deep; front tibiai without 



hook. TlIYMAH'S. 



Nemosoma culindricnm. Lee, linear, cylindrical, black, the base 

 of elytra, antenna; and legs reddish, length 4.5 mm., has been taken 

 near Cincinnati. 



