32 C0LE0PTERA OF NORTH AMERICA. 



Anterior tibiae subpalinate (elytra with three series of dorsal punctures). 



Rothopus. 

 Anterior tibiae expanded at the apex (elytra without dorsal punctures). 



Geopinus. 

 Anterior tibire normal in form ; 

 Menturn strongly toothed ; 



Apical angles of the joints 1 — 3 of the anterior tarsi prolonged into 



spines ; hind angles of thorax rounded. Melanotus. 



Apical angles of the joints of the anterior tarsi not prolonged; hind 

 angles of thorax distinct. Cratacanthus. 



Mentum not toothed ; 



Hind tarsi with the joints 1 — 4 equal ; 



Labrum emargiuate. Cratognathus. 



Labrum not emarginate. Agonoderus. 



Hind tarsi with the joints 1 — 4 decreasing in length, labrum not emar- 

 ginate. Discoderus. 



These genera do not occur on the Pacific slope, with the excep- 

 tion of a single species of Agonoderus found in California. Mela- 

 notus has been found in Arizona. Cratognathus (including Pio- 

 soma Lee.) is represented by two species from Kansas and New 

 Mexico. Of Nothopus but a single species from Kansas is known. 

 Discoderus* is remarkable for its resemblance to species of Har- 

 palus (group Selenophorus), and has three rows of punctures on 

 the elytra ; the middle tibia? of the male are serrate withiu. 



Group II. — Eurytrichi. 



The anterior tarsi are strongly, the middle tarsi usually strongly, 

 sometimes only slightly, dilated, and covered beneath with a dense 

 brush of hair. The head is somewhat narrowed behind the eyes. 

 The first joint of the dilated tarsi of the male is more or less nar- 

 rower than the second. 



Ligula dilated at tip ; mentum not, or only obsoletely, toothed. 



Anisodacttlus. 

 Ligula not dilated at tip, truncate, or subtruncate ; 



Paraglossse narrow, curved, not longer than the ligula; 



Mentum not toothed. Xestonottjs. 



Mentum toothed. Spongopus. 



Paraglossae broad, rounded, longer than the ligula ; 



Mentum not toothed (body pubescent). Amphasia. 



Mentum toothed (body glabrous). Eurytrich0S. 



* Pangus americanus Motsch. (Bull. Mosc, 1859, ii. 137), from Cali- 

 fornia, seems to belong to Discoderus. The genus is not, however, known 

 to me as occurring west of the Rocky Mountains. 



