of the Amazon Valley. 301 



elytra taper a little from the base to the extremity, the 

 hind thighs are very much shorter than the apex of the 

 elytra, but the specimen is most likely a female. 



Hah. — St. Paulo, Amazons. 



9. Ihidion unicolor. 

 White, Cat. Longic. Brit. Mus. p. 233. 



Parvum, angustum, lineare, castaneo-rufum, nitidum ; 

 capite impunctato; thorace cylindrico, aequali, Isevi; 

 elytris apice bispinosis, spina exteriori valde elongata 

 obliqua, supra passim punctulatis, hand setosis ; femoribus 

 modice elongatis, clavatis. 



Long. 2f lin. ( ? ?). 



Hah. — River Tapajos. 



10. Ihidion lineolatum, n. sp. 



Elongatum, lineare, angustum, setis perpaucis vestitum, 

 castaneum, politum ; capite et thorace sericeis, punctulatis, 

 hoc cylindrico, sequali ; elytris apice sinuato-truncatis et 

 bispinosis, spina exteriori majori recta, supra politis, 

 punctulatis (apice Isevibus), medio utrinque lineola dis- 

 coidali elevata alba, suturae parallela, extus late nigro- 

 marginata ; antennis articulis 3-5 paullo incrassatis et 

 infra longissime ciliatis ; femoribus abrupte clavatis. 



Long. 4i lin. ( ^ ?). 



Hah. — Ega. 



Genus Compsa. 



Perty, Del. An. Art. Bras. p. 92; Lacord. Gen. viii. 333. 



Characters of Ihidion, with the exception that the 

 hinder tibise have no trace of carinas. It seems to me 

 preferable to limit the genus to those species in which 

 the third joint of the antennae is carinate, leaving those 

 in which there is no trace of carina either on the antennas 

 or tibiae in the genus Heterachthes. 



