74 FAMILIES OF PETALOCERA WHICH FEED ON 



< darker- coloured species are often to be found regaling 

 themselves with the sap which flows from the wounds of 

 trees ; while C aurata, F. with its more brilliant compa- 

 nions is only to be found on flowers. 



Olivier united theFabric'an genus TncAms with Cetonia: 

 and if indeed the state of the science at that time be taken 

 into consideration, this arrangement was rather an improve- 

 ment thau otherwise ; for the genera were few into which 

 the Petalocera were then divided ; and Trichius is so inti- 

 mately allied to Cetonia, that with the early entomologists 

 nothing could apparently be more useless than the insti- 

 tution of the genus, or more artificial than tlie principles 

 upon which this institution was founded. Since the 

 publication, however, of Olivier's work the science has 

 made rapid progress, and Trichius may now with safety 

 be regarded as a natural group of the Cetoniida, contain- 

 ing several genera, the institution of which is become 

 necessary from the number of species that have of late 

 years been added to our lists. That Trichius is a natural 

 group is suflSciently clear from the larvae of this genus 

 living in putrescent wood, an economy in some measure 

 different from the little that is known of Cetonia, and in- 

 deed from all we are acquainted with in the history of the 

 other Thalerophagous Petalocera. The Trichii conduct 

 us, almost without interruption, to the form of the Gla- 

 phyrida, and it is not by any means unlikely that the 

 habits of these two groups may in some respects approach 

 nearer to each other than those of the first-mentioned 

 insects and of the other Cetoniida. This family however 

 may be distinguished from the Glaphyridce by having 

 their labrura concealed under the clypeus, whereas these 

 last have it exserted and very prominent. 



