390 COLEOPTERA OF NORTH AMERICA. 



Some of the species live ou leaves aud flowers, others are found 

 under bark. 



Groups of genera seem to be indicated, but the characters, 

 when illustrated by foreign genera, appear to be very indefinite. 



Our genera may be arranged as follows: — 



Intercoxal process of abdomen broadly triangular. Group Lystronychi. 



Mandibles not prominent, emarginate at tip. Frosteuus. 



Intercoxal process narrow, acute; 



Mandibles emarginate (rarely truncate). 2. 



Mandibles acute at tip ; 6th ventral segment visible. Group Cteniopi. 9. 



2. Body Upiform ; protborax subquadrate, narrower than the elytra, 



which are elongate and deeply striate ; penultimate joint of tarsi 



lobed. Group Upisell^. 



Mandibles subtrtmcate ; last joint of maxillary palpi very long, 



outer side nearly twice as long as the basal. \ Stenochidus. 



Body oval, prothorax widest at base, basal angles distinct. 



Group CisTEL^. 3. 



3. Penultimate joint of tarsi lobed. 4. 

 Tarsi not lobed beneath. 5. 



4. Last joint of maxillary palpi with the apical side longest. Allecula. 

 Last joint of maxillary palpi with the apical and outer sides nearly 



equal. Hymenorus. 



5. Last joint of maxillary palpi broad triangular. 6. 

 Last joint of maxillary palpi elongate triangular. Cistela. 



6. Third antennal joint nearly equal to 4th. 7. 

 Third antennal joint much shorter than 4th ; Gth ventral segment 



visible. 8. 



7. Front tarsi as long as the tibiie ; antenna slender. Isomira. 

 Front tarsi shorter than the tibiae ; antennje stout. Mycetochares. 



8. Antennae strongly serrate, 2d and 3d joints equal. Chromatia. 

 Antennae elongated, not serrate, 3d joint longer than 2d. 



Capnochroa. 



9. Hind coxae divided by a transverse groove, the posterior portion larger, 



flat, with the hind edge acute. 10. 



Hind coxae divided into two nearly equal jjortions. 1 1 . 



10. Front tarsi of % elongated, deformed. Androchirus. 



11. Antennae slender ; hind angles of prothorax rectangular. Cteniopus. 



Stenochidus and Prostenus are exclusively Californian; the 

 latter is also represented in South America : Hymenorus, Cistela, 

 and Mycetochares occur on both sides of the continent; the 

 other genera only in the Atlantic region. 



