NORTH OF MEXICO. 263 



TRIBE III EPITRAGINI. 



Body generally elongate oval, winged ; epistoma with at least a prominent middle 

 lobe in our species ; labrum prominent ; mentum large, entirely rilling the gular cavity ; 

 elytra with narrow epipleura? ; metasternum long ; parapleural narrow ; middle coxse en- 

 tirely enclosed by the sterna, hind coxa? approximate, intercoxal process of abdomen 

 acute ; tarsi usually pubescent beneath. 



Than this tribe there is probably no other more difficult of position ; each genus pos- 

 sessing characters peculiarly its own, yet all are connected by many points of structure, 

 rendering the tribe at least as natural as any of those which precede. Composed origin- 

 ally in our fauna of but one well defined genus, with characters unknown in any other 

 preceding or following it in the Tentyriidae, it was not a matter of any great trouble to 

 assign it to a position in an analytical table. The addition of one other genus renders its 

 study no less difficult in our fauna than Lacordaire found it in the genera of the whole 

 world. 



Two genera alone compose this tribe in our fauna, and may be readily distinguished 

 from each other as follows : — 



Mesosternum divided, receiving the presternum. epitragus. 



" not divided, presternum not prolonged. schoenicus. 



EPITRAGUS, Latr. 

 Epitragus, Latr.. Hist. Nat. Crust, et Ins. X, p. 322. 



The characters of this genus have been so thoroughly exposed by Lacordaire (Genera 

 des Coleopteres V.) that it is unnecessary to repeat, while any characters peculiar to our 

 species, or not heretofore noted, will be developed either in the table which follows or in 

 the description of each species. For a long time but one species was known in our 

 fauna; our collections now contain eight, either described within a very few years or now 

 for the first time made known. The epistoma varies considerably in outline and to the 

 same extent in our species as has been already noticed in foreign ones. 

 Our species may be arranged as follows : — 

 Thorax narrower than elytra ; supra-orbital ridge distinct. submetallicus. 



Thorax as wide at base as elytra, 

 Thorax dissimilar in % and 9. 



Anterior angles of thorax very acute and more or a c u t u s . 



less prominent. arundinis. 



canaliculatus. 

 Thorax similar in both sexes. 



Eyes with supra-orbital ridge ; elytra not pubescent. piuinosus. 



Eyes without " " ; elytra pubescent. 



