301 
of the Amazon Valley. 
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, sequali, Igevi ; 
elytris apice bispinosis, spina exteriori valde elongata 
obliqua, supra passim punctulatis, haud setosis ; femoribus 
modice elongatis, clavatis. 
Long. 2| lin. ( ? ?). 
Hah. — River Tapajos. 
10. Ihidion lineolatum, n. sp. 
Elongatum, lineare, angustum, setis perpaucis vestitum, 
castaneum, politum ; capite et thorace sericeis, punctulatis, 
hoc cylindrico, aequali ; elytris apice sinuato-truncatis et 
bispinosis, spina exteriori majori recta, supra politis, 
punctulatis (apice laevibus), medio utrinque lineola dis- 
coidali elevata alba, suturas parallela, extus late nigro- 
marginata ; antennis articulis 3-5 paullo incrassatis et 
infra longissime ciliatis j femoribus abrupte clavatis. 
Long. 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 tibiae have no trace of carinae. 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 antennae 
or tibiae in the genus Heterachthes. 
