152 COLEOPTER'A OP NORTH AMERICA. 



Group I.— Chalcophoree. 



Insects of large size, readily known by the antennal pores being 

 diffused on the sides of the joints, but sometimes only near the 

 inferior margin, and by the mesosternal suture being indistinct. 



Chalcophora is generally distributed through our territory, and 

 some of the species are abundant in the Middle States ; the other 

 two genera are found in Texas, New Mexico, and Arizona. The 

 male of Chalcophora has a distinct sixth ventral segment. 



Antennae inserted under a ridge ; rnentum rounded in front ; posterior tarsi 

 with the first joint elongated. Gyascutus. 



Antennae inserted in small foveae ; mentum broadly emarginate in front ; 

 posterior tarsi with the first joint elongated. Chalcophoka. 



Antennae inserted in large foveae ; inenturu broadly rounded in front ; pos- 

 terior tarsi with the first joint not elongated. Psiloptera. 



Group II. — Buprestes. 



Species of moderate size and usually of elongate form ; the 

 antennal cavities are small, and the front is not lobed before the 

 antennae ; the pores of the latter are placed in foveae situated on 

 the inferior margin of the joints, except in Cinyra, where they are 

 terminal. The species of Dicerca and Poecilonota are of a dull 

 bronze color; some are abundant; they are remarkable for the 

 tips of the elytra more or less prolonged, forming a kind of tail. 

 Sexual characters vary in the different genera, and in the groups 

 of species of each genus ; they are found in the form of the ante- 

 rior or middle tibia?, in the outline of the tip of the fifth ventral 

 segment. I have not observed a distinct external sixth segment 

 in the male of any species. Dicerca and Ancylochira are gene- 

 rally diffused ; the other two genera are not yet found west of 

 Platte River. 



Presternum obtusely rounded behind ; 

 Mentum entirely corneous ; 



Scutellum small, rounded. Dicerca. 



Scutellum very transverse, truncate. Pcecilonota. 



•Mentum membranous anteriorly. Ancylochira. 



Prosternum acute at tip. Cinyra. 



Group III.— Anthaxiae. 



Species of small size, usually flattened, rarely linear; the pro- 

 sternum is acutely angulated on the sides behind the coxa3, and 



