GREEN OR LIVING VEGETABLE MATTER. 71 



Dynastida, has been already shown ; and if our attention 

 be transferred to the thalerophagous insects, we shall 

 also experience no trifling difficulty in the attempt to 

 separate them from the Cetoniidcc and AnoplognathidcEy 

 but especially from the latter. In fact, the principal 

 distinction that I have observed to exist between these 

 families is, that the mandibles of the Rutelidce are ge- 

 nerally prominent, whereas those of the Arioplognathidcz 

 are concealed beneath the clypeus ; the maxillas of the 

 latter are also more obtuse than those of the former family, 

 which are always sharply dentated at the apex. With 

 respect to the Cetoniida, their membranaceous mandibles 

 form an obvious and easily seized character of separation. 

 It is indeed not a little curious, that while we observe 

 among the Rutelida and Geotrnpidcz that such genera as 

 Macraspis and Athyreus approach so nearly in habit and 

 general form to the respective families of Cetoniidas. and 

 Scarabaidce, there should still be the same parallel di- 

 stinction kept up in both circles with respect to the texture 

 of their mandibles. 



The Riitelida may be said to have been first indicated 

 by Olivier, who formed his third division of Cetonia of 

 such insects as those composing the new genera Macraspis 

 and Chasmodia. This excellent entomologist remarked 

 that they appear to connect Cetonia with Melolontha, but 

 in some respects to approach nearer to the last. This 

 hint was considerably improved upon by Latreille, who 

 united with the above insects the Melolontha 6-pnnctata, 

 Fab., and gave to the whole the generic name of Rutela. 

 In the Histoire Gentrale des Insectes et des Crustaces, 

 M. Latreille also observes that the Rutelce have the palpi, 

 maxillae and mentum of Melolontha, with the labrum of 



