284 



Genus XIV. — Achenium, Leach. Depressum. 1 



Tribe II. — Stenides (Longipalpi, Lat.) 



The antennae inserted either between or in front of the eyes ; the labrum 

 truncated, transverse ; the maxillary palpi almost as long as the head, the last 

 joint subulate, withdrawn, and concealed ; the head with a distinct neck ; the ab- 

 domen, in the living insect, generally stretched lengthwise ; the legs simple ; the 

 tarsi pentamerous. 



i. The antennae inserted before the eyes, thickened towards the apex. 



A. The fourth joint of the tarsi bifid. 

 Genus I. — Pjederus, Auct. morio, littoralis, riparius, ruficollis, longius- 

 culus, extensus, angustatus. 7. 



b. The fourth joint of the tarsi entire. 

 Genus II — Rugilus, Leach ( Stilicus, Latr.) orbiculatus, laevigatas, fus- 

 culus, bicolor, castaneus, rubricollis. 6. 



ii. The antennae inserted in front of the eyes and thickened suddenly at the 



apex. 

 Genus III. — Eristhetus ( Evwsthetus, Grav.). scaber. 

 in. The antennae inserted between the eyes and thickened suddenly at the 

 apex. 

 A. The ligula obsolete; the anus with two setae. 



Genus IV Dianous, Leach, caerulescens. 1. 



b. The ligula extended. The anus without setae. 

 Genus V. — Stenus, Latr. bipustulatus, maurus, juno, ater, boops, cicinde- 

 oides, oculatus, tarsalis, binotatus, bifoveolatus, buphthalmus, canaliculars, niger, 

 nigritulus, geniculatus, proboscideus, pallipes, argus, fuscipes, opticus, carbonarius, 

 circularis. 22. 



Tribe III. — Oxytelides ( Denticrura, Latr.) 



The antennae inserted in front of the eyes, beneath an elevated and prominent 

 margin of the head. The labrum transverse and entire. The palpi shorter than 

 the head, the joints distinct and the terminal one subulate. The head with a dis- 

 tinct neck. The abdomen in the living insect only partially stretched lengthwise. 

 The anterior tibiae only compressed, and generally externally denticulato-pectin- 

 ated. The tarsi trimerous or tetramerous. 



i. The four anterior tibiae denticulato-pectinated. 

 A. All the tibiae entire. 



Genus I. — Bledius, Leach., ( Siagona, Prognatha, Latr.) tricornis, tau- 

 rus, unicornis, elongatus, fracticornis, castaneipennis, atricapillus, pallipes, femora- 

 11s, talpa, arenarius. 11. 



