CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 285 



CARABIDyE (GROUND BEETLES) 



Common Genera (after Leconte and Horn) : 



A. Middle coxal cavities entirely closed by the sterna (Fig. 185). 



B. Head with two punctures above the eye, each bearing a single bristly 

 hair. 

 C. Margin of elytra interrupted at posterior end and with a distinct 

 internal fold; three basal joints of antennae glabrous. 

 D. Last joint of palpi as long as or longer than the next to the 

 last and cylindrical. — Pterostichiis. 

 DD. Last joint of palpi shorter than the next to the last. — Amara. 

 CC. Margin of elytra not interrupted posteriorly and without an 

 internal fold. 

 D. Penultimate joint of labial palpi with but two bristly hairs; 

 elytra truncate at tip; front tibias slender; tibial spurs 

 short, head constricted behind the eyes. — Lebia. 



Pig. 185. — Prosterna of beetles. A, Coxal cavities (CC) confluent and open 

 behind; B, coxal cavities feeparated and open behind; C; coxal cavities separated 

 and closed behind. {After Wickham.) 



DD. Penultimate joint of labial palpi with a number of bristly 

 hairs in front and always longer than last joint; first 

 antenna! joint elongate; head elongate-oval, prolonged 

 behind the eyes. — Galerita. 

 BB. Head with but one bristle-bearing puncture above the eye. 



C. Elytra truncate at apex; mandibles with a bristle-bearing punc- 

 ture in outer groove; hind coxae often separated. — Brachiniis 

 (Bombardier Beetle). 

 CC. Elytra always entire; mandibles without a bristle-bearing 

 puncture; hind coxae contiguous. 

 D. Antennas with only two basal joints glabrous; black, 

 front tarsi of male dilated and with two rows of small 

 scales beneath; first joint of hind tarsus not longer than 

 the two following. — Harpaliis. 

 AA. Middle coxal cavities not entirely closed by the sterna (Fig. 185). 



B. Hind coxas not separated; labrum not forked; third joint of antennae 

 cylindrical. — Carabus. 

 BB. As in B, but third joint of antennae compressed. — Calosoma. 



