Stnphi/Iinida of the Amazon Valleij. o89 



])arts of the l)ocly. Legs dark reddish. Prosternum pro- 

 minent, but not carinate in the middle in front; meso- 

 sternum with a prominent piece betAveen the middle coxa?, 

 Avhich are therefore distinctly separated ; metasternum 

 smooth, shining black, deeply channelled. In the male 

 the ventral plate of the 6th segment bears a large and 

 deep, almost horseshoe-shaped impression, Avhich is sur- 

 rounded by a kind of margin, and has a peculiar granular 

 pubescence along its sides ; the 7th segment bears a similar 

 but more elongate impression, the bottom of which is 

 covered by the peculiar granular pubescence; the apical 

 portion of this segment is produced in the middle as a 

 broad lobe ; the punctures on the under face of the hind 

 body in this sex are coarser than in the female. 



The female lacks the impressions described above, and 

 the produced lobe of the 7 th segment is narrower and 

 more pointed. 



Amazons; three females, one male. One of these 

 specimens is indicated as being from Ega. 



Ohs. — The structure of the 8tli segment of the hind 

 body and of the sedeagus in this species are peculiar; the 

 dorsal and lateral plates of the former are formed much as 

 in Osorius, but each lateral plate bears a pencil of elongate 

 delicate hairs ; the ventral plate appears to be altogether 

 absent; the ffideagus is complicated in its structure and 

 laterally asymmetrical, and the missing ventral plate of 

 the 8th segment appears to me to be attached to one side 

 of the ajdeagus as a lateral appendage thereof. 



2. Holotrochus si/ntheticiis, n. sp. Piceus, antennis tes- 

 taceis, pedibus rufis ; capite, thorace, ely trisque pernitidis, 

 glabris, parcius sat fortiter punctatis, thorace versus an- 

 gulos posteriores acute rectos fovea magna; abdomine 

 apicem versus attenuato, subtiliter pubescente, fere opaco. 

 Long Corp. 2 — 2 4 lin. 



Antennte yellow; 1st joint rather long and stout, not 

 much concealed by the clypeus, 2nd and 3rd joints sub- 

 equal, rather slender, 4, 5 and 6 small, not differing much 

 from one another, the 6th hardly so long as broad; joints 

 7 — 11 much lai-ger than the preceding ones, 7 — 10 

 scarcely differing from one another, each distinctly trans- 

 verse, 11th scarcely so broad as 10th, obtusely pointed. 

 Head small, much smaller than the thorax ; the eyes pro- 

 minent; the clypeus rounded; the surface pitchy, very 



