StaphylinidcB of the Amazon Valley. 359 



coarsely punctured, obsoletely bisulcate, with an extremely 

 narrow carina at the vertex. Thorax a good deal nar- 

 rower than the eljtra, a good deal longer than broad ; 

 the sides rounded in fi-ont of the middle, and narrowed 

 behind the middle ; the surface covered with a very dense, 

 transversely rugose punctuation. Elytra quite as long as 

 the thorax, coarsely, deeply and very closely punctm-ed, 

 the shoulders standing abruptly out from the base of the 

 thorax. Hind body slender and elongate, the basal seg- 

 ment distinctly margined, the following segments each 

 constricted in front of the middle ; the constricted part 

 obscurely margined, the apical part not margined; the 

 surface rather closely punctured, the punctuation on the 

 basal segment distinct, but not coarse, on the penultimate 

 segments indistinct; the front part of the two basal segments 

 finely carinate on the middle. Legs yellow, coxas pitchy, 

 the knees infuscate ; the 4th joint of the tarsi small, and 

 scarcely lobed. 



In the male the under surface of the 6th segment of the 

 hind body is clothed with fine, pale-yellow pubescence, 

 and is distinctly emarginate at the hind margin ; the 3rd, 

 4th and 5th segments also have the hind margin very 

 obscurely truncate in the middle, the 7 th bears a narrow, 

 very elongate notch. 



Ega ; a single male. 



Obs. — I have not referred this species to any of the 

 generally received sections, because doing so would be 

 very likely to create confusion about it. The tarsi 

 might be described as having the 4th joint simple, but 

 this would not be strictly correct, and the same remark 

 would be applicable if the hind body were described as 

 unmargined. The species suggests at first sight an alli- 

 ance with S. speculator. 



2. Stenus ohductus, n. sp. Niger, subnitidus, palpis 

 fla\as, antennarum basi pedibusque testaceis, femoribus 

 tarsisque apicem versus infuscatis ; fronte bisulcata, vertice 

 carinato; thorace transversim rugoso-punctato, elytris 

 foi-titer denseque punctatis, interstitiis versus suturam 

 latioribus ; abdomine crebre distinctius, apicem versus 

 obsolete punctato, segmento basali margiuato. Long, 

 corp. 2^ lin. 



AntenntE rather short, pitchy, with the basal joints 

 yellow ; palpi pale yellow. Head with the eyes scarcely 



