of the Amazon Valley. 105 



base and a few scattered marks blackish, an indistinct whitish 

 line obliquely crossing the disk. Body beneath testaceous, 

 clothed with pile of the same colour. Legs and tarsi reddish, 

 spotted with grey and black. 



One example, taken at S. Paulo, Upper Amazons. The spe- 

 cies also inhabits South-eastern Brazil, specimens from Rio 

 Janeiro (taken by Mr. Squires) not differing from the Amazonian 

 example except in being rather duller in colour. 



Genus Alcidion (Dej. Cat.), Thomson. 

 Thomson, Classif. des Cerambyc. p. 12. 



Char, emend. Thorax free from tubercles on the disk, or at 

 most but slightly uneven, its sides unarmed. Elytra broad and 

 convex at the base, thence narrowing in a nearly straight line 

 to the apex, with the surface sloping equally in that direction ; 

 the apex truncated and toothed or spined, and the centrobasal 

 ridges more or less prominent. Apical segments of the abdomen 

 and ovipositor not produced in the female. Thighs abruptly 

 clavate ; basal joint of the tarsi generally longer than the two 

 following united. 



As above defined, the genus Alcidion will comprise a con- 

 siderable number of species distinguished from Am?iiscus by the 

 peculiar shape of the elytra, and from other allied genera by the 

 thorax wanting the lateral spines. It is divisible into two groups, 

 — one of which is distinguished by the species having a raised 

 line along the whole length of the elytra on each side, from the 

 centro-basal ridge to the external apical angle ; and the other by 

 the absence of these lines, the centrobasal ridges at the same 

 time being very prominent. The Amazonian species belong 

 wholly to the second group*. 



* A. latum (Thomson, I. c), of Mexico, seems to belong to the first group; 

 also Leiopus emeritus (Erichson, Conspectus Ins. in Peruana, p. 147) of 

 Eastern Peru. The two following should also be added : — 



A. bispinum (Dej. Cat.). Modice elongatum, apud humeros latum, postice 

 declivum et attenuatum, fusco-testaceura griseo olivaceoque variegatum. 

 Caput nigrum. Antennae fusco-testacese, articulo basali subiter cla- 

 vato, clava infra barbata. Thorax griseo-olivaceus. Elytra apice 

 sinuato-truncata, angulo interno acuto, externo longe mucronato, supra 

 utrinque bicarinata, carinis lajvibus, interstitiis punctatis, carina centro- 

 basali nigro penicillata ; grisea olivaceo varia, fascia pone basin nigri- 

 cante. Subtus testaceum, sternis nigricantibus. Pedes testacei, griseo 

 maculati. Long. 3^ lin. Hab. Rio Janeiro. 



A. lineatum, u. sp. Elongatum, apud humeros minus latum, olivaceo- 

 fulvum, olivaceo-fusco varium. Caput olivaceum. vertice fusco bi- 

 punctato. Antennae fusco-testaceae, articulo basali sensim clavato, 

 infra planato et barbato. Thorax medio fusco bivittatus. Elytra valde 

 elongata, punctata, apice sinuato-truncata, angulo interno acuto, ex- 



