Juneigoo.] CaSEV : On NORTH AMERICAN COLEOPTERA. 127 



paltearctic provinces. It is distinguished from the other tribes of the 

 Atomariinse, excepting the Sternodeini, by the structure of the pro- 

 and mesosterna, and in the close juncture of the prothorax with the 

 hind body, and, in the extremely specialized Ephistemus, also by a 

 form of anterior coxa, antennal club, antennal clefts of the prester- 

 num and form of scutellum which are wholly foreign to the rest of 

 the family. The post-coxal plates of the first ventral segment, 

 though feebly developed, should also be alluded to as an important 

 distinguishing character. In the general structure of the body, legs, 

 palpi and tarsi it is however a perfectly normal member of the sub- 

 family Atomariinas. The elytra are never margined at base, the pro- 

 notum is always unimpressed, and the deeply seated anterior coxae are 

 transverse and subcylindrical and attached near the sides of the body, 

 the cavities acutely angulate externally. The species before me may 

 be assigned to the two following widely differentiated genera: — 



Antennae free, the club more slender and bilaterally symmetric, the grooves before the 

 eyes and prosternal clefts wholly obsolete ; scutellum transversely oval as in 

 Atomariini ; prothorax more transversely truncate at base, feebly arcuate at the 

 middle * Curelius 



Antennae partially received in repose within narrow deep grooves before the eyes and 

 in a broad shallow cleft and excavation between the presternum and hypomera, 

 the club rather more developed, parallel, loose and asymmetric, the joints being 

 more developed on the inner side ; scutellum still more minute, cordate, pointed 

 behind and as long as wide or longer ; prothorax broadly angulate at base. 



Ephistemus 



These genera are related to the Atomariini through the singularly 

 synthetic genus Tisactia described above, which has the unimpressed 

 pronotum, broad, fiat and laterally margined prosternal process, an- 

 tennal insertion and sensible, though somewhat differently formed, 

 post-coxal plates of the Ephistemini, the loosely connected body and 

 prothorax and free prosternal process of the Atomariini, and a strongly 

 margined elytral base, which very exceptional character is foreign to 

 both but existent to a well-developed degree in Tomarus of the Cryp- 



tophaginre. 



Curelius, gen. nov. 



This genus is founded upon the Ephistemus dilutus of Reitter, and 

 exiguus of Erichson, and, as far as known to me, is exclusively 

 European. Although abundantly distinct from Ephistemus, it does 

 not seem to have been recognized thus far by Reitter and other 

 European authors. 



