ON DECOMPOSED VEGETABLE MATTER. 63 



bones : but whether this be owing to their whiteness*, or 

 to the fleshy substance that may still remain attached to 

 them, or to any vegetable matter whose growth may be 

 particularly favoured by the presence of such substances, 

 it would be difficult to say. Pallas even, who observed 

 several of these insects in Siberia, only says that " sub 

 cadaveribus astivo ardore exsiccatis cum Histeribus et Der- 

 mestibus hospitatur ;" from which expression it must be 

 considered as anticipating an observation, if we conclude 

 with Olivier that the insect feeds on such carcases. To 

 these remarks I have only to add another circumstance, 

 which I hope will excite the entomologist to study the 

 economy of these insects, and so decide whether in reality 

 they form an exception to the herbivorous disposition of 

 the rest of the Petalocera. — In the Memoires pour VHis- 

 toire des Insectes, Degeer says of his Scarabe a tubercules 

 (which according to Schonherr is the Trox luridus Fab.), 

 that M. Acrelius had found it in rotten wood in Pennsyl- 

 vania. 



Of all the Petalocera, the Trogida appear to approach 

 the nearest in general habit to the Saprophagous RecU- 

 cera, though they differ most widely in the characters of 

 the mouth. They delight in cadaverous matter like the 

 Ulster. Like this last insect their head is sunk in the 

 thorax in a very peculiar manner, and moreover both of 

 them have the curious habit when alarmed of counter- 

 feiting death, by applying their feet and antennas close 

 to the body, and ceasing all motion until their fear may 

 have subsided. There is also a most striking general 



a There are few entomological collectors not aware of the advantages 

 to be' derived from exposing in the sun any thing white, such as linen, &c. 

 for the purpose of attracting the Coleoptera, 



