lo 



U\)c /Iftoutb^^roans an^ otber Cbaractenstics 



of tbe 

 :fiSnti6b Geobepba^a (Ground prebaceoiis JSeetles). 



By Robert Gillo. 

 Plates I., IL, III. 



PERHAPS a few words of general introduction may not be 

 out of place to get as clear an idea as possible as to what 

 the characteristics of the Coleoptera really are. Of all the 

 different characters by which beetles may be known, we can only 

 detect two which are constant — namely, Mandibulate mouth- 

 organs, and Complete metamorphosis. By the latter term we mean 

 that they pass through four stages : the egg, larva, quiescent pupa, 

 and imago or perfect insect. It ought to be stated in passing that 

 Kirby and Spence in their great work, and other old authors, 

 describe the metamorphosis of beetles as incomplete. This was 

 evidently the accepted opinion of the naturalists of that age, but 

 now the metamorphosis of beetles is always considered by 

 naturalists to be complete. 



Since writing the above, "Westwood's Introduction to the 

 Modern Classification of Insects " has come into my possession, 

 and in it I find this note : — " It has been usual to apply the cha- 

 racter of the pupa to designate the peculiar nature of the meta- 

 morphosis in general. This is, however, very incorrect ; since the 

 Coleoptera are thereby defined to have an incomplete metamor- 

 phosis, whereas their metamorphoses are complete, in the ordinary 

 acceptation of the word, the pupa being, on the contrary, incom- 

 plete. Moreover, Linnaeus applied this and other similar terms to 

 the pupa and not to the metamorphosis ; the confusion originating 

 in their misappropriation by Fabricius." The pupae of beetles 

 generally have all the parts of the future imago plainly visible, 

 being encased in thin sheaths. In some instances, however, the 

 limbs are closely soldered to the body, and apparently enclosed in 



