208 NATURAL ARRAXGEMENT OF IXSECTS. 



interesting group of insects. It may be as well to 

 mention, that the Lamellicornes compose the " Chi- 

 lognathiform Stirps " of Mr. MacLeay, as detailed in 

 the work above mentioned. 



(181.) The two families of Cetoniad^e and Scara- 

 BJEivs., as it has long ago been demonstrated, compose 

 the typical and sub-typical families of the lameOicorn 

 beetles. They consequently possess, in their full deve- 

 lopement, all the characters here assigned to the tribe. 

 The CetoniadcF, from living on the fresh sap of plants, 

 have been termed Thalerophagous* Their colours, in 

 harmony with the delicacy and pureness of their food, 

 with few exceptions, are elegantly varied, or uncommonly 

 splendid. As a further distinction, Mr. MacLeay men- 

 tions that the elytra do not, as in the ScarabcEidcB, en- 

 tirely cover the abdomen : this, however, although a 

 useful, is but a secondary, and very uncertain character; 

 inasmuch as we are entirely ignorant how far this devi- 

 ation of structure is connected with the habits of the 

 insects in question. As the Cetoniadce feed upon living 

 vegetables, and the Scarabceidce upon such as are de- 

 composed, the student may naturally inquire how these 

 distinctions are to be traced in the cabinet of the ento- 

 mologist who may be altogether ignorant of this differ- 

 ence.'' and what are the external characters which accom- 

 pany such a dissimilarity of habit? These, at least, were 

 the first questions that occurred to us, many years ago, 

 upon commencing the study of the lamellicorn tribe. 

 We cannot discover, however, in the valuable pages of 

 the HorcB Entomologicce, any information which supplies 

 this knowledge. Nevertheless, it may be safely stated, 

 that Nature has marked these two families, in their ex- 

 ternal structure, in as remarkable a manner as she has 

 done in their economy. This difference is manifested 



* As this group, however, seems to correspond with such as we have 

 termed families in other divisions of the animal kingdom, and as uniformity 

 of nomenclature is so highly desirable in all branches, we shall on this, and 

 all other occasions, take the family name from that division which is the 

 most typical. See our remarks on the rank of groups, in Classification of 

 Animals, p. 373. 



