PREDACEOUS GROUND-BEETLES. 43 



A. r.iidy of till' u.siial obluUK form ; incso-steniiiin and scutolliim distinct. 



15. Thorax with a sliarp lateral margin; tibia- without notch; laot joint of palpi large and tri- 

 angular ; eyes uiodi-rate, size usually large. 

 C. Size large; elytra with numerous stri;p. 

 D. Head of onlinary form ; epii)lt-ura narrow. * 



E. Thiril .joint of the antenna- cylindrical ; color mostly black CAUAni's, 11. 



E E. Third joint of anteunii- flattened ; body with rich metallic tinta Cai-Osoma. 21. 



D D. Head narrow ; epipleune very wide Cvchkls, 25. 



C C. Size medium or below ; elytral stria- not e.xceeding nine ; color black Nebiua, 18. 



15 15. Thorax without a sharp lateral margin ; tibiiu 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- 



dcmien ; elytra with round shallow pits Ei.AriiuiJs, 10. 



F F. Thorax deiiressed with an obtuse nuirgin, nearly aa wide as abdomen; color 



bronze-black Nonoriiii.i's, 8. 



.\ A. Body almost orbicular; mesostenium covered by the presternum; scutellum wanting ; colors 

 variegated Omoi-iiuo.n, 9 . 



Subfamily SCARITIUES. 



The most conspicuous character of this sub-family is the peduncu- 

 lated abdomen, producing a sei)aration between it and the thorax, 

 [Fig. 10.1 whence this section was called Bipartiti by Latreille But 

 the most essential and uuexce[)tional character is the form 

 of the anterior tibu', which are widened and flattened, 

 and toothed on the outer side, and with the outer angle 

 .prolonged into a long point. This structure enables these 

 iisects to dig in the earth, a habit expressed by the name 

 )f the typical genus Scarites of Fabricius, meaning a 

 scratchcr. The subfamily is also remarkable for the ex- 

 scAKiTEs (Asiii^. treme disparity in the size of its species, Pasimachus 

 Shamioir-rft.RU^^^^ usuallv an iucli 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 antennae elongated. Size comparatively large. 



13. Thorax with the hind angles prominent. Size large, or very large. Elytra usually with 



a blue border PASi.MACHi'e. 14 



B B. Thorax rounded behind. Size medium, or above Scaiute.s, 3 



A A. First joint of autennic moderate. Size small, or very small. 



C. Thorax somewhat sqmire-shaped ; abdomen elongate and depressed Ci.mxA, 35 



CC. Thorax sub-globose ; abdomen ovoid DYsrHiKirs, 38 



Pasimachus is an exclusively North American genus. The P. margi- 

 nntus of Bonelli, and the P. elongfl^us, 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. ehmyatufi, 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 larvtB of Cicindela. 



* The epipleitra is the margin of the wing-cover which is bent iibruptly downwards, and covers the 



side of the abdomen. 



r 



