ON THE CETONIIDiE OF SOUTH AFRICA. 
13 
13. In this genus, generally, the terminal brush of the maxilla is inserted in the triangular 
orifice of a short triangular corneous process, which terminates the maxilla, and appears articu- 
lated to it. In some of the floral species, this pencil of hairs or brush is very long, and admirably 
calculated for sucking up the honey of flowers ; but in other sub-genera, such as Platygenia 
for example, the terminal brush may rather be considered to line the edge of the small trian- 
gular corneous process which terminates the maxilla and appears articulated with it. In such 
insects this process of the maxilla is not so palpiform as in those Trichini which inhabit flowers. 
14. The larva and metamorphosis of the sub-genus Trichinus have been perfectly well 
explained by Professor Dehaan of Leyden, who shews that they bear more similarity to those 
of Glaphyrida and Melolonthida, than to those of the sub-genus Cetonia. This is a curious 
fact, and strongly illustrative of the danger attendant on our assuming a method of division 
instead of following the mode of variation. What groundwork for a natural division, for 
instance, appears more natural than metamorphosis ? Certainly none ; and yet if we divide 
the family of Cetoniida by this rule, we shall place half of the contents along with the 
genus Melolontha! If, on the other hand, we follow the maxim of variation, and watch 
how the metamorphosis changes, we only arrive at the fact, that Trichinus (i. e. an aberrant 
genus of Cetoniider) is intermediate between the Glaphyridcc and the typical Cetoniida, 
inasmuch as it has the larva of the former, and the imago of the latter. 
But we proceed to detail the various sub-genera of Trichinus. Fabricius was not acquainted 
with the singular insects which compose the first of them. 
A. — Body depressed and sides thin. 
First joint of maxillary palpi 
distinct. 
&ufcstnerau 
1 Platygenia, M‘L. Anterior tibiae externally bidentate. 
2 Campulipus, K. Anterior tibia', externally tridentate. 
, 3 Trichius, M‘L. 
B. — Body and sides thick. First 
joint of maxillary palpi eva-< 4 
nescent. 
Valgus, Sc. 
1*5 
Osmoderma, Lp. Sr. 
j Anterior tibiae externally bidentate in general. Body 
i covered with hairs or scales. 
f Anterior tibia; externally multidentate. Body spotted 
1 with scales. 
f Anterior tibiae externally tridentate. Body depressed, 
1 without hair or scales. 
Sub-genus 1. Platygenia, M‘L. 
15. Of this sub-genus only one species is certainly known ; although, to say the truth, 
Gory’s figure of what he calls Platygenia Zairica, is so unlike the insect which I so named 
some years ago, that one is almost inclined to believe he may have fallen accidentally upon 
a new species of the groupe. Indeed, I consider the Trichius barbatus of Schonherr to 
belong certainly to the sub-genus. The mouth of Platygenia approaches very near in 
structure to that of Osmoderma, however different it may seem in external appearance. It 
is in fact, the mouth of an Osmoderma, with all the parts flattened, and excessively 
widened, differing only in having the terminal lobe of the maxillee transversal and small. I 
imagine, indeed, that the true character of this sub-genus is founded on the comparative 
evanescence of the palpiform terminal process of the maxillae. 
16. The general form of the thorax of Platygenia, and its very depressed body, make me 
think that we can proceed from it to Campulipus, by means of some sections hitherto 
