454 Mr. H. W. Bates on the Longicorn Coleoptera 
the exception of the margins and suture near the apex, which 
are blackish. 
I found one individual only of this form at Ega, on the trunk 
of a tree. 
5. Gymnocerus monachinus, White. 
- Anisocerus monachinus, White, Cat. Long. Col. in Brit. Mus. ii. p. 406, 
pl. 10. f.3 
This magnificent species varies in size from 7} to 11 lines. 
The fourth antennal joint is gradually and slightly dilated at the 
apex, the third is simple. The ground-colour of the upper sur- 
face in the ¢ is chalky white, in the 2 rose-red, the latter being 
very bright during life. I found the species only within a radius 
of twenty miles of Ega, on the Upper Amazons. At Nauta, 
540 miles to the west of Ega, the species recurs in a modified 
state ; the modification is one of colour only, but is remarkable 
for its distinctness and its occurring in both sexes. The follow- 
ing is a short description of it :— 
Local var. A. Nautensis; 8 lines, ¢ ¢. 
The white fascia of the elytra is very much broader ; the se- 
cond black belt extends posteriorly along the suture, and the 
tooth-shaped black streak near the apex is replaced by a distinct 
isolated round spot. 
I received one pair of this variety-from Nauta, on the banks 
of the Upper Amazons, in Peru. 
Genus OnycHocerws, Serv. 
Serville, Ann. Soc. Ent. Fr. iv. 83. 
Inthis genus the antenne have eleven joints in both sexes, but the 
terminal joint is much thinner than the others, and claw-shaped. 
In the males several of the apical joints are fringed beneath 
with long hairs; the second joint in both sexes is remarkably 
elongated. The sterna are in some species simple, and in others 
tuberculated, showing that this character has no generic value ; 
for this genus is one of the most natural of the whole tribe. 
The tarsi of all the legs are strongly dilated ; the fore tarsi of the 
males are more widely broadened than ‘the others, but they are 
not fringed with long hairs. The ligula is elongated, not dilated 
on the sides, but simply rounded; the two lobes approximate, 
but are not united on their inner edges. 
1. Onychocerus scorpio, Fabricius. 
Lamia scorpio, Fabr. Mant. Ins. i. 131. 8. 
» Fabr. Ent. Syst. 1. 11. 273. 26. 
This well-known and common species is always found on the 
trunk of a particular kind of wild fruit tree called by the natives 
