NOTES ON CLASSIFICATION. 99 



of our shores would reveal many more species pos- 

 sessing similar habits. 



Having got thus far, it may perhaps be as well to 

 pause for a moment, and glance back upon the 

 ground we have passed over. Hitherto everything 

 has gone on pretty smoothly, and although we have 

 once or twice met with instances of the difficulty of 

 persuading nature, for our own convenience, to come 

 within the compass of a definition, we have found no 

 obstacles to prevent our holding on in a tolerably 

 straight course. We passed easily enough from the 

 Geodephaga to the Water Beetles, and from these 

 through the Whirligigs to the Philhydrida ; there 

 was nothing particularly startling in the transition 

 from these to the Necrophaga, but here a difficulty 

 presented itself, for although there can be no doubt 

 of the close affinity between the Brachelytra and the 

 typical Carrion Beetles, it is equally certain that the 

 next group which we shall have to take into consider- 

 ation is just as nearly allied to the species of the 

 genus Dermestes and its allies. Here therefore is at 

 all events a splitting of the " mighty chain of beings " 

 referred to in the hackneyed quotation from Thomson ; 

 the difficulty is by no means lessened by the con- 

 sideration of the close affinity between the Brache- 

 lytra and the Geodephaga, and a careful consideration 

 of the whole affair will show clearly enough that we 

 can never hope to exhibit all the relations of created 

 beings by proceeding in a straight line. 



It was the perception of this fact that led M'Leay, 

 about thirty years since, to put forward the opinion 

 that every group of natural objects was to be repre- 

 sented by a circle, including a certain number of 

 subordinate groups arranged round its circumference, 



