iStaphylinidcc of tlic Amazon Valley. 361 



closely pimctured, with tlie interstices near the suture 

 distinct, broader than the external ones. Hind body rather 

 slender, subcylindric ; the basal segment margined, the four 

 following ones each Avith a slight margin on the basal 

 portion ; the segments rather closely but obsoletely punc- 

 tured, the basal one rather more distinctly than the 

 others, and with a cai'ina at the base in the middle, the 

 two following ones wdth more indistinct carinre ; all the 

 segments Avith a well-marked, fine, depressed, pale-yellow 

 pubescence. Legs moderately long, reddish-yellow ; the 

 femora, as also the tibite and tarsi, more obscure in colour 

 in their apical portion ; 4tli joint of tarsi simple. 



In the male the underside of the 6th segment is flattened 

 along the middle and finely pubescent ; the 7th segment 

 has a very elongate and narrow notch. 



Tapajos ; a single male. 



Ohs. — This species is very closely allied to S. obductus, 

 but is more metallic in colour, rather less elongate in 

 form, has the thorax with the sculpture rather coarser, 

 the sides more rounded, the hind body more obsoletely 

 punctured, and the limbs rather shorter and stouter. 



4. Stenus cognatus, n. sp. ^^neo-niger, subnitidus, 

 palpis flavis, antennis fuscis, basi cum pedibus testaceis ; 

 fronte bisulcata et carinata ; thorace fortiter transversim 

 rugoso-punctato ; elytris fortiter punctatis, interstitiis 

 nitidulis. Long. corp. fere 2 lin. 



Antennae short, yellowish, infuscate at the extremity ; 

 palpi pale yellow. Head nearly as broad as the elytra, a 

 little excavate, and distinctly carinate along the middle. 

 Thorax longer than broad, a good deal rounded at the 

 sides ; the surface coarsely sculptured, with transverse 

 rug£e, the interstices of which are broad enough to be dis- 

 tinctly shining. Elytra about as long as the thorax, 

 coarsely punctured, with the interstices distinctly shining. 

 Hind body slender, subcylindric; the bo sal segment mar- 

 gined, the four following ones each with a slight margin 

 on the basal portion ; the segments rather closely but 

 obsoletely punctured, the basal one rather more distinctly 

 than the others, and with a carina at the base in the 

 middle, the two following ones Avith moi'e indistinct 

 carinfe; all the segments with a fine, depressed, pale-yellow 

 pubescence. Legs modei*ately long, reddish-yelloAv. 



In the male the underside of the 6th segment is flattened 



