69 
blackj and disk with a black mark shaped like a horse-shoe. 
Elytra elongated^ quickly narrowed behind the shoulders, then 
widening slightly, afterwards towards the apex again narrowed, 
the apex itself being rather broad and sin uate-trun cate, the in- 
ternal angle dentiform, the external one produced into a length- 
ened spine; the shoulders are acute, and from their edge com- 
mences the lateral carina, which is very prominent, but is so 
placed as to leave the deflexed portion of the elytra beneath it 
visible from above ; the surface is rather thickly punctured in 
the middle towards the base, sparingly so in other parts; the 
centro-basal ridges are short, but extremely elevated, hooked 
posteriorly, and surmounted by a crest of black hairs ; the colour 
is grey, with a rosy tint in some lights, and towards the apex 
there is on the disk of each a black curved line and spot resem- 
bling the note of interrogation. Legs (especially the posterior 
thighs) elongated ; like the under surface of the body, they are 
of a dusky hue. 
This elegantly shaped and curiously marked insect occurred 
only at Ega, on dead branches in the forest. 
5. Alcidion olivaceum, n. sp. 
A. oblongum, postice modice attenuatum, tomento olivaceo signa- 
turis obscurioribus variegato vestitum : elytris apice breviter 
oblique truncatis, femoribus crassissimis. Long. 5^ lin. 
Head dusky; antennse dusky reddish, base of joints from the 
third pallid. Thorax olivaceous grey, with a short black streak 
in the middle of the hind margin. Elytra rather broad at the 
shoulders, and narrowed curvilin early thence to the apex, which 
is briefly an^ obliquely truncate ; the lateral carina is less pro- 
nounced than in the last species, but the centro-basal ridges are 
very prominent ; they are hooked behind, although not crested 
with hairs ; the surface is rather uneven, having two faint and 
obtuse dorsal carinse, which, however, are effaced shortly behind 
the middle ; the colour is olivaceous grey, varied with small 
dusky spots which accompany the carinse, and two oblique discal 
streaks placed behind the middle. Beneath and legs dusky, 
varied with grey ; base of thighs and tip of tarsi testaceous ; the 
thighs are short and very thickly clubbed. 
Ega, Upper Amazons. 
6. Alcidion minimum , n. sp. 
A. parvum, depressum, postice modice attenuatum, fusco-cinereum, 
fuliginoso maculatum : elytris apice oblique sinuato-truncatis, 
angulis obtusis, carina centrobasali modice elevata. Long. 2 lin. 
Head sooty brown ; antennae with the basal joint strongly 
flexuous beneath, sooty brown. Thorax smooth, sides rounded. 
