56 FAMILIES OF PETALOCERA WHICH LIVE 



become artificial, and only useful as serving to subdivide 

 our more general ideas. In my opinion, therefore, the 

 Scarabccidcz compose such a numerous family that for the 

 sake of convenience we not only ought to retain all the 

 established genera, but in several cases even to add a great 

 many more to the present list, requiring only that they 

 shall always be supported by characters visible to the 

 naked eye. 



This same difficulty of subdivision is not by any means 

 peculiar to the Scarabceidct, but will be experienced also in 

 the equally numerous family of Cetoniidce, which answers 

 to those insects in the other circle. The Scarabczidcz also con- 

 stitute the only family of the saprophagous circle containing 

 insects having the produced sternum and lobate thorax, 

 which form such remarkable characters in some of the 

 Cetoniidce: — all which circumstances prove, if farther 

 proofs were indeed wanting, that these two families bear 

 to each other a certain analogical relation. 



The Scarabczidcz afford a curious example of the artifi- 

 cial nature of the sections that may be founded on the 

 disposition of the tarsi. If the Heteromera for instance be 

 a natural section, as stated in some of the latest entomo- 

 logical works, a genus such as Onitis ought a fortiori to 

 compose alike division, since in one at least of the sexes it 

 wants the tarsi of the fore-legs altogether. Yet how obvi- 

 ously would such an arrangement oppose all our notions 

 of natural affinities ! 



In none of the Coleoptera perhaps does the general 

 structure of the feet assume so extraordinary an ap- 

 pearance as with the Scarabaidce. The externally den- 

 tated and somewhat curved fore-feet of these, with the 

 tarsi nearly obsolete, can only vie in the anomaly of their 



