310 Mr. H. W. Bates on the Longicom Coleoptera 



side, one of the elevations near the anterior part of the disk on 

 each side forming an acute tubercle ; the colour above is rusty 

 ochreousj the hind part having two blackish lines, which are 

 severally continuous with the rounded velvety black spots on the 

 elytra, on each side of the scutellum. The elytra are of a light 

 green hue, except on the apical fourth, where there is a large 

 ashy-ochreous spot, streaked with dark brown, very similar to 

 the streaked apical spots in the genus Eudesmus. The under- 

 side of the prothorax and breast is greenish ashy. The legs are 

 green, varied with greenish ashy. These green and rusty- 

 ochreous hues, combined with the rugged surface of the insect, 

 give it very much the appearance of a mossy fragment of wood, 

 when it is seen clinging close to a dead bough, as is the habit 

 of the creature. 



Genus Trestonia, Buquet. 

 Buquet, in Thomson's ' Arcana Naturae,' p. 45. 



Like many other generic groups of Longicorns, the present 

 one is recognizable rather by a similar general form and colora- 

 tion than by definite structural characters. The species are 

 cylindrical or linear and depressed in shape, and exhibit a dark- 

 brown or black curved mark towards the apex of -the elytra, 

 preceded by a pale-ashy or greenish patch, and succeeded by 

 fulvous strigse nearer the apex. The possession of this charac- 

 teristic mark points to a near relationship with Eudesmus and 

 Ecthcea; but some species answer very well to the definition of 

 the genus Hesycha, as far as sti'ucture is concerned. All the 

 species, however, are more linear in form than the Hesycha, and 

 the antennae in nearly all are more nearly approximated at their 

 bases. The head is variable in width, and the forehead is some- 

 what convex in the middle ; the latter is in most species clothed 

 with pale-coloured tomentum. The antenniferous tubercles, in 

 the broader-headed species, have prominent and sometimes 

 eornuted inner angles. The antennae themselves are slender 

 and setaceous, in the males often twice the length of the body ; 

 their basal joint is clavate, and the third joint, with few excep- 

 tions, a little curved. The thorax is cylindrical and uneven, 

 never short and broad. The elytra are linear, obtusely rounded 

 at the apex, free from centro-basal elevations and tubercles ; the 

 shoulders are prominent and acute, and curved anteriorly. The 

 legs are moderately short, the thighs clavate, the claw-joint ro- 

 bust, as is universal in the Oncideritae, and equal in length to 

 the three remaining taken together. 



The Ti-estunicB, like the other genera of the present group, 

 are found on branches of trees, clinging closely and gnawing the 

 bark and surface-wood. 



