of the Amazon Valley. 49 



a triangle ; but the posterior one is sometimes wanting, and in 

 some of the smaller species the whole are obsolete. The elytra 

 are narrowed from the shoulders to the apex. The muzzle is 

 very short, being prolonged very little beyond the lower margin 

 of the eyes ; but it is very broad, and the lower angles are pro- 

 minent. The antennae are much longer than the body in both 

 sexes, fringed with hairs beneath ; the third joint much the 

 longest, the first being about two-thirds its length, and dilated 

 (chiefly on its inner side), from near the base, into an elongate 

 club. All the femora are strongly clavate ; the fore tibiae of the 

 6 , in those species which approach nearest the genus Acrocinus, 

 are bent near the tip, the tubercle being very prominent, and 

 the first joint of the tarsi much elongated. All the tarsi are 

 remarkably narrow and elongated, especially the claw-joint, more 

 so in some species than in others, a character which distinguishes 

 Oreodera from Acanthoderes and the allied genera. The 6 fore 

 tarsi are elongated and fringed with hairs. The sterna are 

 very broad, the anterior acetabula circular, but the sutures are 

 slightly gaping along their whole length. The hgula (in O. 

 glauca) is membranous, narrow, deeply and narrowly cleft, and 

 its outer margins are regularly rounded. The lobes of the 

 maxillae are small and narrow ; the mentum extremely short and 

 broad. 



The species of this genus are numerous in South America. 

 Their habits are similar to those of Acrocinics, with the excep- 

 tion that they are generally found adhering very closely to the 

 twigs or bark of the dead trees on which they are found; and 

 their colours being assimilated to those of the wood or bark, they 

 are with difficulty detected. The smaller species are exclusively 

 confined to the slender branches, the length and slenderness of 

 their tarsal joints and claws being specially adapted for clinging 

 to them. The females deposit their eggs on the bark ; and the 

 larvae, when hatched, penetrate into the wood. 



§ Disk of thorax with three or two prominent tubercles : tips of the 

 elytra truncated. 



1. Oreodera undulata, n. sp. 



O, elongata, depressa, tomento tenuissimo holosericeo griseo-olivaceo 

 vestita : elytrorum apicibus oblique ^inuato-truncatis, dimidio 

 basali granulato-punctato, apicali lineis undulatis griseis et fuscis 

 ornate. Long. 7 lin. c? . 



Head sooty-brown, opake : eyes nearly touching the central 

 furrow on the vertex. Antennae sooty-brown, the base of each 

 joint from the third light grey. Thorax with large lateral 

 tubercles and three discoidal ones — two transverse before, and 



Ann. if Mag. N. Hist. Ser. 3. Vol. viii. 4 



