of the Amazon Valley. 289 



also occurs at Cayenne, and is there still darker in its 

 colours, the upper-side being black, with rufous lines on 

 the elytra, and the legs partly reddish. In all, the mark- 

 ings are the same ; the two whitish spots, which take the 

 place of the anterior fascia, being elongate and nearly 

 parallel, the outer one a little posterior, and near the 

 lateral margin. 



9. Onomidolon biarcuatum. 



Ibidion biarcuatum, White, Cat. Longic. Brit. Mus. 

 p. 228. 



Elongatum, sparse pilosum, politum; capite nigro; 

 thorace lae vi, nigro antice et postice fulvo, vel fulvo macula 

 postica antice trifida nigra ; elytris depressis, melleo-flavis, 

 apice late albo-testaceis, arcu longo nigro, utrinque a 

 humero usque ad marginem pone medium, suturam 

 hand attingente, maculas pallidas marginales includente, 

 et postice fascia obliqua pallida marginata ; elytris lateri- 

 bus impunctatis; pedibus rufo-fulvis. 



Long. 6-7 lin. 



Hab. — Tapajos and Ega. 



In Tapajos examples only, the thorax is black, with 

 reddish margins. 



10. Gnomidolo7i simplex. 



Ibidion simplex, White, Cat. Longic. Brit. Mus. p. 230. 



Angustissimum, lineare, politum, nigro-piceum, sparse 

 pilosum; elytris testaceo-fulvis, linea arcuata fusca, a 

 medio baseos prope ad marginem lateralem pone me- 

 dium, suturam haud attingente, maculam marginalem 

 pallidam includente, apice indeterminate albo-testaceis; 

 antennis (articulis 3 basalibus nigro-piceis exceptis) 

 pallidis; pedibus elongatis, fulvo-testaceis, femoribus 

 posticis dimidio apicali nigris. 



Long. 34-41 lin. ^ ? . 



Hab. — Forest of Altar do Chao, Tapajos ; common. 



