204 COLEOPTEBA OF NORTH AMERICA. 



Group II. — Erotes. 



In this group the front is short, gibbous, sometimes trans- 

 versely margined, the beak is wanting and the mouth deflexed ; 

 the last joint of the maxillary palpi is longer than the preceding, 

 acute at tip. 



The antennae are moderately compressed, with the second joint 

 usually at least one-half as long as the third, which is not longer 

 than the fourth. Prothorax carinate, divided into cells or feebly 

 channelled ; spiracle, not tubular, depressed. Elytra reticulate, 

 costate, and cancellate, or with ribs scarcely elevated and inter- 

 stices with single small quadrate depressions, never widely dilated 

 behind. Front coxae rather narrowly separated. 



Prothorax strongly carinate, sides divided by an oblique ridge from the 

 hind angles. Lopheros. 



Prothorax many celled, sides divided by a strong transverse ridge. Eros. 



Prothorax not carinate, feebly channelled behind, sides not divided hy 

 transverse ridge. Plateros. 



Group III. — Lygistopteri. 



The insects of this group, of which two genera are represented 

 in our fauna, are easily distinguished by the pubescent velvety 

 surface, and the feebly striate, not reticulated elytra. The head 

 is prolonged into a long or short broad beak, which latter form is 

 rather a muzzle, like that of many Fodahri; the eyes are mode- 

 rate and the front broad ; the antennae are rather widely separated, 

 subscrrate, with the joints thicker and less compressed than in 

 the other two groups; the second joint is one-half as long as 

 third, which is shorter than fourth. Maxillary palpi with last 

 joint snbtriapgular, apical side oblique. Prothorax channelled, 

 margins usually thickened, reflexed, with an oblique ridge run- 

 ning forwards towards the median groove; the thickened side of 

 the prothorax is usually foveate at the middle of its length, thus 

 recalling Polemiua of the Tclephoridffi, as the form of the muzzle 

 does Podabrus. 



Beak long, narrowed at tip; prothoracic channel forming a rhombic cell, 

 the sides of which connect with the oblique ridge, sides not thickened ; 

 maxillary palpi with distal side of last joint curved. Lygistopterus. 



Beak short, broad ; prothorax with thickened sides, oblique ridges short ; 

 maxillary palpi with distal side of last joint oblique. Calochromus. 



