CERAMBYCIDAE. 293 



coxal process ; the episterna of the metathorax are narrowed 

 and almost pointed behind, and the epimera are not longer than 

 the episterna. 



In the % the 5th ventral segment is transverse, and the Gth is 

 visible, in the 9 the 5th is prolonged, and Gth not visible. 



The scutellum is always rounded behind; the mesonotum is 

 punctured at the sides, the stridulating plate is wanting in 

 Tetropium ; feebly developed, and divided by a broad median 

 vitta in Criocephalus; tolerably large and channelled in Asemum 

 and Nothorhina; large and undivided, as in mos + Cerambycini, 

 in Opsimus, and Smodicum. 



An undifferentiated, or synthetic tribe, having affinities in 

 various directions; the maxillary lobes are very feebly developed, 

 and almost atrophied in Asemum, showing an affinity with 

 Spondylis and Prionidae; the divided stridulating plate indicates 

 a relation with Lepturini; Tetropium diverges towards Callidium, 

 Criocephalus with its coarsely granulated eyes tends towards the 

 genuine Cerambycini, while Opsimus and Smodicum seem to be 

 entirely isolated, having no relation with other members of our 

 fauna. 



The groups may be thus separated. 



Epimera of mesothorax normal, truncate at inner end; 



Base of prothorax normal. Asemi. 



Base of prothorax emarginate, rilled by a thin plate. Opsimi. 



Epimera of mesothorax acutely pointed internally. Smodici. 



Group I. — Asemi. 



The insects of this group are generally Callidioid in form, the 

 head short, the mandibles small, stout, and acute, the palpi nearly 

 equal, or rarely unequal (Tetropium) ; the eyes finely or mode- 

 rately coarsely (Criocephalus) granulated, transverse, scarcely 

 emarginate (Asemum), large, more or less emarginate (Crioce- 

 phalus), divided (Tetropium). 



All the genera except Cyamophthalmus, which has the last joint 

 of the palpi subulate, are represented iu our fauna, and are dis- 

 tributed on both sides of the continent. 



Eyes moderate, transverse, finely granulated, hairy ; 



Antennae finely pubescent. Asemum. 



Antennae coarsely pubescent. Nothorhina. 



