202 THE entomologist's record. 



vast majority of our beetle fauna, and one of the first points which will 

 strike the student of their distribution is its general discontinuity. 

 Many of them no doubt occur wherever a suitable environment exists, 

 as we find Fliilopedon (jeminatus on all the coast sandhills of the 

 kingdom, and may be always sure of the association of Strophmom ns 

 limbatus and Erica wherever the latter may occur ; but the majority 

 we discover in more isolated detachments, the environment may be 

 there and the appropriate beetle absent, and this segregation may 

 occur quite within the limit of range of the species. 



Now discontinuity of this kind, but perhaps on a larger scale and 

 over a wider area, has been held by eminent authority as an indication 

 of extreme antiquity of residence. In the cases under consideration, 

 however, I think we shall be justified in rather attributing it to the 

 changes which the environment itself has undergone, and that 

 comparatively recently. The Great Britain of a thousand years ago 

 was a very different land from that which we see to-day ; easterly a 

 vast area of fen and marsh land, the midlands continuous forest, the 

 south primaeval open downs and heaths, north and west moors and 

 mountains ; such was the general aspect of Saxon England. Now 

 consider the advent of a more extended agriculture, an ever-increasing 

 rural population, the arable area round the scattered settlements 

 continually growing as these settlements grew into villages, and 

 villages into towns, the plough invading the pasture lands, and the 

 pasture lands ever encroaching on forest and marsh. The effect of all 

 this would be the gradual isolation of such of the fauna as clung 

 tenaciously to the environment of the wilderness, the, I think, probable 

 extermination of some species which once had a place in our fauna — 

 and the diminution of all of them — so that now we find in such a 

 vestige of the primitive world as Askham bog, lingering renuiants of 

 a fen fauna which was once perhaps continuous from Yorkshire to the 

 Wash, and on Cannock Chase and in Delamere forest the last outposts 

 of species such as Miscodera antica and Hijdroporus inoiipiitiia, which 

 once peopled every heathery eminence or mossy hollow between those 

 localities and the mountains of Wales and the moors of Devonshire. 

 Thus it was I believe that lines of communication were cut, not by any 

 natural process but through the agency of man, and what ^^as once an 

 army of occupation is now reduced to isolated and discontinuous 

 garrisons in mutually remote but favourable spots. 



But apart from this obvious discontinuity of distribution we cannot 

 fail to discern a larger grouping of species within approximately definite 

 limits of range, and as we study the subject a little more closely, three, 

 possibly four, separate groups begin to emerge which are assignable to 

 distinct areas, and which, although their limits are not always quite 

 clear, at any rate to our present very incomplete knowledge, still seem 

 to represent separate homogeneities and to have possibly distinct 

 histories and derivations. 



Taking these groups in the order which we may provisionally 

 consider as representing to some extent that of their appearance, we 

 have : (1) A number of species inhabiting more especially the 

 mountains, moors and highlands of the north and north-west. They 

 form the most distinctive fauna of the north and west of Scotland and 

 Ireland, are well represented in the north of England and the 

 highlands of Wales. Many of them, however, are entirely absent from 



