36 COLEOPTERA OF NORTH AMERICA. 



Anillus, Pericompsus, and certain Tachys the tarsi of the male are 

 not at all dilated. The epimera of the mesothorax are more or 

 less triangular. The elytra are entire, and rounded at tip, with 

 the eighth stria usually confluent anteriorly, or nearly so, with 

 the margin sometimes widely interrupted, but usually entire. 



Like the other genera of Carabidoe containing very numerous 

 species, Berabidium consists of groups of species differing greatly 

 in form, and even in the structure of the parts of the mouth; but 

 the characters being evanescent, caunot be used for the definition 

 of genera. 



Our genera are as follows: — 



Eyes wanting. Anillus. 



Eyes small, flat. Lymnjeum. 



Eyes large or moderate, convex ; 

 Anterior tibiae not dilated at the apex ; elytra with scntellar stria ; sutnral 



stria not recurved at the apex. Bembidium. 



Anterior tibise slightly dilated and obliquely truncate at the apex ; elytra 

 without scutellar stria ; sutural striae recurred at the apex ; 



Elytra with the eighth stria interrupted or less deep at the middle. 



Tachys. 



Elytra with eighth stria very deep. Pekicompsus. 



Of Anillus and Lymnseum but single Californian species have 

 yet been found ; the other genera are widely diffused. Blemus 

 cenescens Lee. must be placed in Tachys, the smaller propor- 

 tional size of the third joint of the antennas not being sufficient 

 for generic separation. 



Fam. III.— amphizoidae. 



Mentum deeply emarginate, with a medial tooth ; lobes 

 obtusely rounded; ligula large, quadrate, corneous; gular 

 suture none. 



Maxillae with the outer lobe narrow, glabrous, palpiform, 

 but not biarticulate; the inner lobe curved, acute at the apex, 

 sparsely ciliate, with spines internally. 



Antennas inserted under the front, behind the base of the 

 mandibles; entirely glabrous, polished. 



Prothorax with the epimera and episterna moderately 

 distinct; prosternum produced behind over the mesosternum. 



Metasternum truncate behind, not reaching the abdomen. 



