PREDACEOUS GROUND-BEETLES. 49 



the females are scarcely distingiiisbable. The tooth of the meutum is 

 usually simple iu Oodcs and bltid in Amara, but even this character is 

 not invariable. The remark made of rterostichus will apply to Plaixjnm. 

 (Udathm is peculiar in this sub-family for its pectinated claws, and in 

 accordance with this structure its species are often seen on the trunks 

 of standing trees, or under the scales of bark, sometimes in company 

 with 7)rom/?<.s and />e/>m. C. ffref/ariom. Say, is not uncommon. Geopi- 

 nm iiicrassafns, Dejean, has been found in loose soil several feet below 

 the surface. Agonoderm pallipcsy Fab., is one of our most common in- 

 sects. It is often attracted into houses by the lamps, in summer even- 

 ings. The other species of this genus are rare. 



The following are the literal meanings of the foregoing generic terms : 



.4 )tiso(1actylus — having d'lHsimilar feet. 



ihl>iandropus — male and female feet., referring to the widening of the 

 tarsi in both sexes. 



Harpalus — ravenous. 



iSfi'nolojjhiis — having a narroio neck or thorax. 



BradyceUus — slow footed. 



radius — chaw/eahle^ alluding to their metallic colors, changing in dif- 

 ferent lights. 



CalathuH — a wicker basket^ probably referring to theii' comb-toothed 



claws. 



Flati/n us — depressed. 



Trechns — a runner. 



The origin of the terms Amara and Patrobus, is not apparent. 



Sub family BEMBLDIEDES. 



This subfamily is composed exclusively of very small species, varying 

 from li twentieth to a little more than a (juarter of an inch in length. 

 Their distinctive character consists in the form of the palpi, the last 

 joint being very small and acicular, the contrast being made the more 

 striking by the preceding joint being unusually large and swollen. The 

 si>ecies are numerous, uj)\vards of one bJJfcilred and forty Xorth Ameri- 

 can species having been described, arranged in many sections or sub- 

 genera. They are almost all of a shining black color, but often exhibit 

 beautitul brown or green reHections. They are extremely agile in their 

 motions. A few of the smaller species are found under the bark of de- 

 cayed trees, but the great majority inhabit wet places. Mr. Ilaliday, 

 an accurate English entomologist, relates that some of the species which 

 frequent the sea-shore permit themselves to be submerged by the waves. 



—7 



