42 



ON THE CETONIID^ OF SOUTH AFRICA. 



and subacuminate at apex. The pseudonycliia are large and conspicuous. The mentum, 

 however, is here not deeply emarginate as in Goliathus, but, on the contrary, rather convex 

 in front, so that we have arrived at another sub-genus which has been called Ichnestoma, by 

 M. Gory ; but as this gentleman has favoured us with the derivation of the word which he 

 intended to write, I shall correct his mistake, and call the 



Sub-genus 4. Ischnostoma, G. P. 

 75. It is true, that taking a more extended view of natural affinities than M. Gory, I have 

 given greater latitude, than he has done, to the groupe here called Ischnostoma, but I do not, 

 on that account, conceive myself entitled to deprive that entomologist of the credit of naming 

 this curious sub-genus. Ischnostoma is distinguished from Goliathus, by the mentum never 

 being deeply emarginate, and from the sub-genus Cetonia, by the terminal lobe of the maxilla 

 being excessively small, and almost evanescent. This lobe, as may be expected, is largest in the 

 two aberrant sections which lead to G&liathus and Cetonia; but still is short, in proportion to 

 what we find it to be in those two sub-genera generally. The mandibles here are peculiarly 

 small and rudimentary, as is also the labrum, which is of a singular form in the typical 

 sections, — a form which indeed is different from that of the labrum in all other Cetoniidce. The 

 mentum is never emarginate, but in general convex at the apex. All the known species are of 

 a black hue, that makes them Httle interesting except to the entomologist. From the grains 

 of sand which I have generally found adhering in quantity to the hair which covers the under 

 side of many of these insects, we may imagine that they are inhabitants of a sterile country. 

 Schbnnherr, Latreille, and, more lately, Klug, have all placed certain insects which belong to this 

 sub-genus close to the genus Goliathus of Lamarck. 



SECTIONS OF ISCHNOSTOMA. 



B. — Epimeron distinctlyvisi- 

 ble between the elytra and 

 thorax. Mentum never 

 ■with an acute apex. 



rl CcELOCEPHAL^, M'L. Clypeus horned. Mentum convex in front. 



r Clypeus not horned. Thorax narrower than elytra. Men- 

 turn broader in front. 



J Clypeus not horned. Thorax at base as wide as the elytra. 

 1^ Mentum sub-emarginate. 



f Sides of clypeus not sinuated. Mentum rather short and 

 ^ Epimeron not very con- Heteroclit^, M'L. J wide. Clava of antennse very short. Anterior tibiae 



2 XlPHOSCELlDE^, M'L. 



3 Arcadeje, M'L. 



spicuous between the elytra_J L tridentate externally. 



' and thorax. Mentum tri- ] f Sides of clypeus sinuated. Mentum long, narrow. Clava 



angular with acute apex. '\J> Cuspidate, M'L. <| of antennse very long. Anterior tibise externally bi- 



dentate. 



76. The first of these sections, here called Ccelocephal^, contains two known species which 

 MM. Gory and Percheron have erroneously assigned to their genus " Diplognatha." The 

 Cetonia geotrupina of Schonnherr is possibly a third distinct species. The maxilla here, how- 

 ever, has no tooth on the inner process, like Diplognatha ; and if there be any thing like a 

 tooth on the outer process, of which I am not quite sure, it appears to be merely the acute 

 corner of the horny part which stretches beyond the pencil of hairs. However, I think this 

 must be an approach in some degree to the structure of Diplognatha ; and although I am not 

 prepared to say with M. Gory that it belongs to that sub-genus, I certainly consider it as 

 evidently serving to connect the genera Macrominus and Cetoninus by what is called the 



