144 



Aphodius; and, I might also add, Mesites with Cos- 

 sonus. I believe indeed that Mesites will be found to 

 attain its maximum on the Pyrenees (I already possess 

 two or three species, in abundance, from that region) ; 

 and, if such should be the case, we shall be able to ap- 

 preciate the significance of two representatives so closely 

 allied as the M. Tardii and Maderensis, one of which 

 has been given off in the direction of Ireland, and the 

 other of the Madeiran Archipelago. 



But I will not digress further on the subject of this 

 Atlantic province; since, however much I may indivi- 

 dually regard it as a reality of the past (which the 

 Coleopterous statistics have compelled me to do), it must 

 of necessity remain, as heretofore, a matter of much 

 controversy and doubt. I should indeed apologize for 

 having trespassed on the reader's attention, in wandering 

 thus far from the immediate results of subsidences, 

 which I proposed, at the outset of this chapter, to exa- 

 mine, with reference to the impeded diffusion of the 

 Annulose races. Nevertheless, concluding that a prac- 

 tical illustration of the effects of one of those great 

 downward movements to which geology so repeatedly 

 bears witness would not be irrelevant to the assumed 

 consequences which I had previously ventured to define, 

 I have acted on that judgment; and, having finished 

 my task, will now proceed to notice, briefly, a few other 

 considerations which should not be omitted, when 

 inquiring into insect distribution as influenced by geolo- 

 gical phenomena. 



