196 
square at the apex^ and each one is deeply sinuated in the mid- 
dle, so as to form two projections or lobes. The antennse are 
rather slender, in the female as long as the body, with the basal 
joint tumid on one side at the apex, and the third joint slightly 
curved. 
My specimens differ in colour from the one figured by M. 
Buquet; but I believe them to be referable to the E. quadri- 
cornis of Olivier. The Trachysomus faunus of Erich son (Consp. 
Peru. p. 148) seems to be quite a distinct species of this genus. 
Ecthoea quadricornisj Olivier. 
Cerambyx quadricornis, Oliv. Ent. iv. p. 97, pi. 20. f. 158. 
Talasius quadricornis, Buquet, Thoms. Arc. Nat. p. 100, pi. 5. f. 6. 
The female example now in my collection, and which I found 
at Ega, is lines in length, the head being 2| lines in width. 
The upper part of the forehead is yellow, brown near the crown, 
where it is marked with three black spots; the lower part is of 
a blackish olive- colour, the line of demarcation between the two 
colours being a transverse carina, from which in the male rise 
the two lower frontal horns. The thorax is very uneven on each 
side, one of the elevations near the anterior part of the disk on 
each side forming an acute tubercle ; the colour above is rusty 
ochreous, 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 lather 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 
