OTIORIIYNCHIDAE. 435 



gin, separated by the epimeroii. Metastcnial side piece moder- 

 ately wide, dilated at its anterior end with an acute process of 

 greater or less extent projecting inwards between the mesosternal 

 epiraeron and the body of the metasternuni. 



DIVISION I. 



This division contains those genera in which the mesosternal 

 epimera are small, or at most moderate, the episterna in contact 

 with the elytral margin, the metasternal side pieces rarely of more 

 than moderate width and not dilated at anterior end, and without 

 the triangular process projecting between the nies-epinicra and 

 the metasternuni. The other characters of the division are ex- 

 tremely variable, in all, liowever, the antennse are strongly geni- 

 culate. All the genera of this Division in our ftiuna have a large 

 mentnm concealing entirely the maxillie, excepting in the last tribe. 



The following tribes are represented in our fauna: — 



Thorax without ocular lohes ; 



Antennal grooves (scrobes) lateral directed inferiorly. Brachyderixi. 

 Antennal grooves short, sujjerior, rarely lateral, and then directed 

 toward the eyes. 0TI0RHY^'c■III^M. 



Thorax with ocular lohes more or less distinct ; 



Mentum at least moderate, concealing in great part or entirely tin; 

 maxillffi ; mandibles robust not prominent, scar very evident. 



OrnRYASTINI. 



Mentum very small, maxillse exposed, mandibles prominent, free edge 

 rather thin, scar small, very narrow Dirotognathini. 



As will be seen by the above table the presence or absence of 

 ocular lobes affords the only means of separating the tribes Bra- 

 chyderini and Ophryadini, and the character must be strictly 

 interpreted. The latter tribe has the ocular lobes sometimes 

 very feeble and almost wanting, but as the lobes disappear the 

 fimbriai become more evident. In the former tribe there are no 

 evidences whatever of eitlier ocular lobes or fimbriae. lu one 

 genus, the prosteriium is more emarginate than usual, giving an 

 appearance of slight ocular lobes, but no traces whatever of fimbriii; 

 are seen. In some of the genera of Ophryasl/.ni, the metasternal 

 side pieces become of moderate width, showing somewhat of an 

 approximation to the genera of the second division. The side 

 pieces in the other two tribes hre very narrow and the sutures 

 nearly always obliterated. 



