32 
to the apex, a spot near the shoulders, a large rounded one near 
the lateral margin before the middle, a small one near the apex, 
and one in the middle of the disk, all of a white colour. Body 
beneath black, sides of the sterna and abdomen having large 
white spots. Femora and tibiae black clothed with grey pile ; 
tarsi fulvous. The opposing faces of the prosternum and 
mesosternum are subvertical and sharply bituberculated. The 
four apical joints of the antennae in the <5 are shortened and 
ciliated. 
This extremely beautiful species occurred only at Cai^ara, a 
village nearEga, on the Upper Amazons, on the trunks of felled 
trees in the forest. 
Genus Dryoctenes, Serv. 
Serville, Ann. Soc. Ent. Fr. iv. 24. 
As already remarked, there is no character to distinguish this 
genus from Acanthoderes, with which it will eventually have to 
be incorporated. The species have a much broader and more 
depressed form of body, and the antennae are much longer, than 
is the rule in the genus alluded to. The proportions of the an- 
tennal joints, form of muzzle, legs, male tarsi, and thorax are 
the same as in Acantlioderes. In the style of coloration and 
markings the species resemble most A, bivitta and its nearest 
allies. 
Dryoctenes scrupulosus, Germar. 
Lamia scrupulosa. Germ. Insect, spec. nov. 470, 619. 
There appear to be two somewhat distinct forms or geogra- 
phical races of this species. The example before me, taken on 
the banks of the Tapajos, differs considerably in colours and in 
the shape of the elytra at the apex from the form found at Rio 
Janeiro. The description of Germar with reference to the elytra 
glauco-tomentosa, apice truncata, intus dentata applies to 
the Amazonian example better than to those I have seen from 
the south of Brazil. I do not know whether the latter may not 
be the form described by Serville as D. caliginosuSy his descrip- 
tion not being sufficiently exact to decide. D. caliginosus, how- 
ever, is generally considered to be synonymous with D. scrupu- 
losus of Germar. 
Genus Ozotroctes, nov, gen. 
Head somewhat narrow, antenniferous tubercles raised and 
oblique. Palpi obliquely truncated at their apices, the labial 
more strongly so than the maxillary. Thorax obtusely uni- 
tuberculate on the sides, furnished with two very distinct tuber- 
cles on the disk. Prosternum simply rounded ; mesosternum 
