Genera of the CossonidcB. 521 
and in which the second joint of the funicuhis is consi-)icii- 
ously longer than any of those which follow it. Their 
rostra, too, are usually a trifle longer, and relatively a 
little less thickened, than in 3Iicroxylohius proper, with 
the antennas implanted just perceptibly nearer to the apex ; 
and in the typical members of the group (the A. armatus, 
conicollis, and monillcornis) the two hinder femora are 
furnished with an acute spine at the base of their ujpiier 
edge. In the four remaining species which have as yet 
been detected (namely the terebrans, ohliteratus, debilis, 
and angustus) the femora are unarmed. The A. moni- 
licurnis, however, presents a slight exception as regards 
its funiculus-joints, the last four of which are almost of 
equal length and breadth, — the first of them being scarcely 
at all elongated ; but in every other respect it is typical. 
23. MiCROXTLOEius(ChevroIat, Trans. Ent. Sac. Loud. 
i. 98. 1836). — A more careful examination of the many 
remarkable and dissimilar Cossouids, from St. Helena, 
which I have hitherto recorded (chiefly on account of their 
funiculus being 5-articulate) as Microxylobii, has con- 
vinced me that it will be better (indeed perhaps necessary) 
to treat them as exponents of two distinct genera, — or, if 
we include the comparatively gigantic " M. cossonoides'' 
(which was enunciated by myself, as such, two years ago), 
of three. As thus restricted, the dark and almost im- 
metallic members of the group will be the 3Iicroxijlobii 
proper, — in which moreover the surface, instead of being 
highly polished and perfectly bald, is subopake, more or 
less roughened, and with a tendency to be sparingly 
studded Avith a very minute pubescence (which, however, 
is sometimes barely traceable even beneath a high magni- 
fying power). In fact, although distinct in the M. vestitus, 
and just appreciable in the lacertosiis and dimidiatus, this 
pubescence may be said in the Westiooodii and lucifugus 
to be almost, if not indeed entirely, absent. These five 
species moreover, with the exception of the last, are the 
smallest of the assemblage, and have their rostra relatively 
a trifle broader and thicker (it being in some instances 
almost subtriangular), and the second articulation of their 
funiculus hardly at all longer than those which follow it. 
In the excessive brevity of their metasterna. Micro xylobius, 
Acanthomerus, Lamprochrus, and Amaurorrhinus are 
nearly coincident ; though perhaps it is in Microxylobius 
that it is more particularly shortened. 
