PREDACEOUS GROUND-BEETLES. 
43 
A. Body of the usual oblong form r meso-sternum and seutelluin distinct. 
B. Thorax with a sharp lateral margin ; tibhe without notch ; last joint of palpi large and tri- 
angular ; eyes moderate, size usually large. 
C. Size large; elytra with numerous striae. 
D. Head of ordinary form ; cpiple.ura narrow. * 
E. Third j’oint of the antennae cylindrical ; color mostly black Carabus, 11. 
>> E E. Third joint of antenmo flattened ; body with rich metallic tints CALOsORfA, 21. 
D D. Head narrow ; epipleurte very wide Cychrus, 25. 
C C. Size medium or below ; ely tral striae not exceeding nine ; color black Nbbiua, 18. 
B B. Thorax without a sharp lateral margin ; tibiaj with a small notch and with one of the 
spurs at a distance from the apex ; last joint of palpi moderate ; eyes very large ; size 
small. 
F. Thorax almost cylindrical, without salient margin, and much narrower than the ab- 
domen ; elytra with round shallow pits Elapurus, 10. 
F F. Thorax depressed with an obtuse margin, nearly as wide as abdomen; color 
bronze-black Notjopiiilus, 8. 
A A. Body almost orbicular ; mesosternum covered by the prosternum; scutellum wanting; colors 
variegated Oriopiiron, 9. 
Sub-family SCARITIDES. 
The most conspicuous character of this sub-family is the peduncu- 
lated abdomen, producing a separation between it and the thorax, 
[Fig. io.| whence this section was called Bipartiti by Latreille But 
A. j, />. the most essential and unexceptional character is the form 
| w of the anterior tibm, which are widened and flattened, 
and toothed on the outer side, and with the outer angle 
JjL S, prolonged into a long point. This structure enables these 
/J i Iml nsects to dig in the earth, a habit expressed by the name 
^ f \ lifrV -'f the typical genus Scaritcs of Fabricius, meaning a 
A ’tjpr 1 watcher. The sub-family is also remarkable for the ex- 
soahites (Asi'im- treme disparity in the size of its species, Pasimachus 
ShTudoir-ilftitiioybeiiig usually an inch or more in length, and Dyschirius 
less than an eighth. The anterior tarsi of the males are very rarely, 
and then but slightly dilated. 
A. First joint of antennm elongated. Size comparatively largo. 
B. Thorax with the hind angles prominent. Size large, or very large. Elytra usually with 
a blue border Faslmachub, 14 
B B. Thorax rounded behind. Size medium, or above Scarites, 3 
A A. First joint of antennae moderate. Size small, or very small. 
C. Thorax somewhat square-shapod ; abdomen elongate and depressed Clivina, 35 
CO. Thorax sub-globose ; abdomen ovoid Dyschirius, 38 
Pasimachus is an exclusively North American genus. The P. margi- 
natus of Bonelli, and the P. elongatus, LeConte, are common insects, 
usually found under stones or old logs. Dr. LeConte has given some 
interesting details of the habits of the larva of P. elongatus, which 
digs a deep hole in the ground, resting with its head at the entrance, 
and springing upon any prey that may come within its reach, thus re- 
sembling in its habits the larvae of Cicindela. 
* Tlio epipleura is tho margin of the wing-cover which is bent abruptly downwards, and covers the 
side of the abdomen. 
