16 
ON THE CETONIIDiE OF SOUTH AFRICA. 
Sub-genus 4. Valgus, Scriba. 
23. This answers to the genus Acanthurus of Kirby, easily known by its depressed form, 
long trapezoidal prothorax, and short elytra. In the only section of this sub -genus which 
I know, there is a mucro arming the anus in one of the sexes, and which is probably the 
ovipositor. I have always found the species of Valgus , either at the roots of trees, or at the 
foot of walls, but never on flowers as Latreille says that he has found them. The section 
Geometrici of the last sub-genus is covered with scales, and so is this sub-genus ; but we still 
want some sections of Valgus to connect the Geometrici with the common Trichius hemipterus 
of Fabricius. Indeed, I am not aware that the present sub-genus has ever been resolved into 
sections. There is one species at the Cape, viz. 
Sp. 6. (Trichinus) Valgus Smithii, n. s. 
Descr. Valgus thorace postice utrinque macula nigra abdominisque fascia alba. 
Long. Corp. 4 lines. 
Note. This species is scarcely distinct from the Valgus hemipterus of Europe. It lias the same rugae 
of the thorax, the same size and general form, and only differs slightly in the disposition of the scales. 
In V. hemipterus for instance, the abdomen is quite white with thickly set scales. In V. Smithii there is 
merely a white band. V. Smithii has also a white mark in the black lateral spot of the thorax. But in 
truth these species come very near to each other. 
Sub-genus 5. Osmoderma, Lp. Sr. 
24. This groupe has been hitherto described and figured with little care. It is said to 
have the terminal lobe of its maxillse corneous. This lobe is not, however, more corneous than 
in any of the other sub-genera of Trichinus. It is an elongated hollow triangle, filled with a 
short thick pencil of hairs. The true characteristic of the sub-genus is the strong corneous 
hook which arms the maxillse on its inner side. These insects live with their larvae in rotten 
wood. They have been called Gymnodi by Mr. Kirby, and made by him part of his genus 
Trichius. I am acquainted with two sections of Osmoderma, which are peculiar to Europe 
and North America. The type is Trichius Eremita of Fabricius. I have already said that, 
different as Platggenia Zairica is in aspect from all the other known species of the genus 
Trichinus, it comes in every essential respect exceedingly close to Osmoderma. I suppose the 
name given by Lepelletier and Serville to this sub-genus, alludes to the scent of Russia 
leather, which the European species O. Eremita emits when it is handled. 
Genus II. CRYPTODINUS, Mild. 
25. We have seen that none of the known species of the genus Trichinus have the terminal 
lobe of their maxillae furnished with teeth. The sub-genus Osmoderma, was indeed sup- 
posed to possess this structure, but erroneously ; although it has certainly a tooth at the 
point of the inner process. This formation appears to prepare us for the maxillae of the 
present genus Cryptodinus, of which the character is always to have a corneous tooth or 
teeth on the terminal process. Indeed, that tooth which Osmoderma possesses on the inner 
process of the maxillse, brings it, of all the sub-genera of Trichinus, the nearest to the genus 
Cryptodinus. This genus may be always known by its depressed elongated form, and by 
the under side of the mentum having a process, while the outer side of the terminal piocess 
of the maxilla lias no brush. Cryptodini are found in all the principal divisions of the 
globe, Europe excepted. They are nevertheless chiefly intratropical insects, which are 
