28 COLEOrTERA OP NORTH AMERICA. 



nally, the anterior deeply emarginate within and sometimes with 

 the outer apical angle obliquely truncate (certain Tachys). Tarsi 

 slender, claws simple, rarely serrulate {Elaphropus). Surface 

 usually glabrous, pubescent in Tachypu)^. 



The males have usually two joints of the anterior tarsi dilated 

 and squamulose or pilose beneath, but in some Tachys the tarsi 

 are similar in the sexes. 



This tribe is as well defined as any in the Carabidae, the form 

 of the'last joint of the palpi being peculiar to it and giving the 

 name by which it is often known, Subulipalpi. 



The serrate claws of Elaphropus Motsch., an Asiatic genus, 

 is a very singular character to occur in the present tribe. The 

 species of this genus resemble Tachys and notably incurma^, etc. 



The genera known to occur in our fauna are as follows: — 



Anterior tibise not obliquely truncate at apex. Sutural stria not recurved 

 at apex 

 Eyes large or moderate ; posterior coxae contiguoiis. 



Elytra punctured without stria, surface pubescent. Tachypus. 



Elytra striate or striato-punctate, glabrous, Bembidium. 



Eyes entirely wanting ; posterior coxfe separated. Anillus. 



Anterior tibise obliquely truncate at apex. Sutural stria recurved at apex. 



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



Tachys. 

 Elytra with the eighth stria very deep. Pericompsus. 



With Bembidium are included Lymnseum and also for the 

 present Amerizus Chaud. The latter genus was founded on 

 Trechus spectabilis Mann., from the peculiar structure of the 

 outer maxillary lobe which has the two pieces connate. Beneath 

 his generic description Chaudoir takes occasion to refer Trechus 

 oblongulus Mann., to the genus Lymnxum as an aberrant 

 species. On dissection the outer maxillary lobe appears more 

 completely consolidated than in the true Amerizus. Rather than 

 recognize a genus with two so dissimilar species it seems better 

 to ignore the character and refer both to Bembidium where each 

 will find better associates. It is well known that the mouth 

 parts in Bembidium vary otherwise to an extent which would be 

 considered generic in other parts of the series, but all attempts to 

 divide it have thus far been unsuccessful, the characters becoming 

 evanescent. 



