45 
but merely to resort to them for the purpose of gnawing the 
bark. 
I have seen a second and undescribed species of Platysternus 
in the collection of Count Mniszech, at Paris. 
Genus Polyrhaphis, Serv. 
Serville, Aim. Soc. Ent. Fr, iv. 26. 
From the seemingly capricious way in which the various parts 
of structure that, in other Coleoptera, furnish signs of affinity 
are modified from genus to genus in the Longicorn family, it is 
difficult to decide on the true position and relationship of the 
present group. In the general shape of the body, as well as in 
the form of the muzzle, thorax, and apex of the elytra, it seems 
to approach the genus Acrocinus. The antennse, however, are 
quite glabrous beneath, instead of being ciliated partially or 
wholly as in Acrocinus \ and the fore tarsi of the d are dilated 
and ciliated, instead of being simple. In the proportions of the 
apical joints of the antennse there is a great similarity between 
Polyrhaphis and the Anisocerinse, the terminal joint in both 
sexes being extremely short compared with the penultimate. 
This seems to be a significant character. The form of the 
muzzle, too, is not greatly different from that of the Anisocerinse; ^ 
but the general form, the shape of the elytra and of the sterna, 
reveal no affinity with that group. The genus seems to have no 
close relationship with any other group of Lamiaires : it shows 
some resemblance to Acrocinus and the Anisocerinse ; but many 
intermediate links are wanting to prove a genealogical relation- 
ship. The prosternum is extremely narrow in this genus, and 
the mesosternum is contracted in the middle between the 
haunches. The anterior acetabula gape widely on the sides, the 
sutures being opened along their whole length. The genus is 
a very natural or well-defined one, comprising a cluster of spe- 
cies which agree with each other in facies as well as in structural 
characters. They are all of large size, have greatly elongated, 
filiform, rather stout antennse, long and acute lateral thoracic 
spines, sometimes directed forwards, and ample oblong elytra, 
whose apices are broadly truncated and spined. 
I. Polyrhaphis spinosa, Drury. 
Lamia spinosa, Drury, Illustr. ii. p. 60, pi. 31. f . 3 (1773). 
Cerambyx horridus, Oliv. Ent. iv. 66, pi. 4. f. 29(1789-1808). 
Lamia horrida, Fabr. Ent. Syst. i. ii. 273. 25 (1792). 
The figures given by Drury and Olivier agree well in shape 
and form of the spines with the insect I have before me, taken 
at Villa Nova, on the Lower Amazons. My example, however, 
appears to be of a lighter colour. The general hue of the to- 
