STAPHYLINID.E. ACHENIUM LATHROBIUM. 565 



Genus DXVIII. — Achenium, Leach. 



Antennw geniculated, inserted behind the eyes, near the base of the mandibles, 

 basal joint longest, the remaining joints clavate, of nearly equal length, the 

 second being shortest, the apical joint acute. Palpi filiform, with the 

 terminal joint minute, subulate: head obcordate : eyes minute, lateral: 

 thorax orate, truncate anteriorly, rounded behind, the disc sparingly 

 punctured: elytra quadrate, depressed: abdomen broad, margined: body 

 depressed: wings ample, sometimes wanting: legs short, stowt ; femora 

 robust^ compressed ; tibia simple ; anterior tarsi dilated in both sexes. 



Achenium has the body much more depressed than any other 

 genus of this family : the palpi are filiform, with the terminal joint 

 minute and subulate ; the thora:: is ovate, truncate in front, and 

 rounded behind, in which particular, exclusively of other oral 

 diversities, it differs from Lathrobium, with which genus it was 

 formerly associated. The only indigenous species is found in grassy 

 places. 



Sp. 1. depressum. Atrum nitidum, antennis pedibus elytrisque apice rufis. 



(Long. corp. 3§ — 4 lin.) 

 Lat. depressum. Gravenhorst. — Ach. depressum. Steph. Catal. 286. No. 3066. 



Curtis, ill. pi. 115. 



Elongate, black, nearly glabrous : head punctulate, with a minute tubercle 

 before the base of the antennae ; mouth rufous : thorax nearly as long as the 

 head, very glossy, with a faint longitudinal line, the sides sparingly 

 punctate, the disc smooth, with two rows of impressions : elytra also 

 punctured, clothed with a short, scattered pubescence, black, with the apex 

 and sides ferruginous : abdomen slightly pubescent, with the tips of the seg- 

 ments reddish : legs, palpi, and antennae ferruginous. 



The elytra are sometimes pale testaceous, with the base of the suture and the 

 outer apex dusky-brown (A. trinotatum. Step, olim.) ; or the insect is alto- 

 gether much more attenuated than usual, and of a paler colour (A. angus- 

 tatum. Steph. Catal. I. c. No. 3067). 



Occasionally found in plenty in the vicinity of London. " In 

 abundance in Copenhagen-fields." — Mr. Ingpen. " On the banks 

 of the Orwell, June 1804."— A^irfe^/ MSS. 



Genus DXIX. — Lathrobium, Gravenhorst. 



Antenna; filiform, not geniculated, basal joint longest and stoutest, obconic, 

 the two following rather longer than tlie remainder, (excepting the terminal 

 oiic, which is lanceolate acute.) clavate, the rest obconic. I'alpl with the 



