Stcq^hi/ lilt idee of the A m azo n Vallci/. 2 1 7 



with a narrow line clown the middle, smooth. Elytra 

 longer than the thorax, densely, rather finely punctured. 

 Hind body quite dvdl, finely and closely punctured. Legs 

 yellow. 



In the male the 3rd segment of the hind body l)cncath 

 has a transverse fiavea in the middle, near the extremity; 

 the 4th segment has a similar but smaller fovea, and is 

 produced into a broad shield, the margin of which is 

 rounded, and densely fringed with long hairs. 



Tapajos ; two specimens, $ and $ . 



Obs. — As my individuals of this species are evidently 

 immature, I have not alluded to their general colour. 



10. Cnjptohium alternans, n. sp. Eufescens, capite, 

 elytris, abdominisrpie apice nigris, pedibus tcstaccis ; tho- 

 race nitido, crebre fortiter punctato, linea media la^vi. 

 Long. Corp. 3 lin. 



Mas: abdomine segmento 3° ventrali apicem versus 

 puncto setigero instructo, segmento quarto medio pro- 

 ducto, cumque puncto setigero, apice longe densequc 

 setoso. 



Var. abdomine segmento ultimo rufescente. 



This species is remarkable by its alternate colouration. 

 Antenua3 as long as head and thorax, the base yellow, the 

 rest duskv reddish ; 3rd joint longer than 2nd, 8th quite as 

 long as 4th, 9 — 1 1 each a little shorter than its predecessor. 

 Palpi yellow ; mandibles red. Head rather broader than 

 the thorax, about as broad as the elytra, dull slaty-black, 

 all the back part densely and distinctly, the front sparingly 

 punctured. Thorax rather narrower than the elytra, straight 

 at the sides, of a rather shining-red colour, coarsely and 

 rather closely punctured, with a line down the middle, 

 smooth. Elytra rather longer than the thorax, dull bluish- 

 black, densely and rather coarsely punctured. Hind body 

 red at the base, the three apical segments blackish ; it is 

 dull, and finely punctured. Legs yellow. 



In the male the 3rd segment of the hind l)ody has 

 beneath, near the extremity, a setigerous puncture ; the 

 next segment has a similar [)uncture, and is moreover in 

 the middle more or less backwards, and has the hind 

 margin fringed with very long hairs ; this lobe is, however, 

 variable in its development, and may be entirely absent, 

 in which case the long hairs fringing the hind margin 

 are also entirely absent ; on dissecthig an individual in 



