196 COLEOPTERA OP NORTH AMERICA. 



Group I. — Chalcophorae. 



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. 



Antennre inserted under a ridge ; nientum rounded in front ; posterior 

 tarsi with the first joint elongated. Gyascutus. 



Antennje inserted in small fovese ; mentum broadly emarginate in front; 

 posterior tarsi with the first joint elongated. Chalcophora. 



Antennae inserted in large foveae ; mentum broadly rounded in front ; 

 posterior tarsi with the first jofcit 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 

 antenme; the pores of the latter are placed in fovese situated on 

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

 terminal. The species of Dicerca and Pcecilonota 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 tibiae, in the outline of the tip of the fifth ventral 

 segment. We have not observed a distinct external sixth segment 

 in the male of any species. Dicerca, Poecilonata, and Buprestis 

 are generally diffused ; the other two genera belong to the Atlantic 

 region. 



Prosternum obtusely rounded behind ; 

 Mentum entirely corneous ; 

 Scutellum small, rounded ; 



Tarsi broad, shorter than the tibise. Dicerca. 



Tarsi slender, as long as the tibiae. Trachykele. 



Scutellum very transverse, truncate. Pcecilonota. 



Mentum membranous anteriorly. Buprestis. 



Prosternum acute at tip. Cinyra. 



Group III. — Anthaxiae. 



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

 sternum is acutely nngulated on the sides behind the coxse, and 



