NOTES ON THE DISTRIBUTION OF THE BRITISH COLEOPTERA. 293 



Peronea, Curt, 

 cristana, Fab. 



ab. desfontainana, Fab. 

 ab. ulotana, Clark 

 ab. spadiceana, Haw. 

 ab. brunneana, Stphs. 

 ab. intermediana, Clark 



Peronea, Curt, 

 cristana, Fab. 



ab. consimilana, Stphs. 

 ab. sericana, Hb. 

 ab. albicostana. Sand 

 ab. rossiana, Fab. 

 ab. combustana, Dup. 



Notes on the distribution of the British Coleoptera. 



By W. E. SHARP. 



(Conclmled from j). 271.) 



Of course it is not to be assumed that climatic conditions even over 

 so small an area as that of the British Islands, do not play an 

 important part in limiting the range of a species, and possibly actual 

 mean temperature may be less effectual in this way, than differing 

 degrees of humidity, and this again will act more effectively, indirectly 

 through food-plants, &c., than directly on the organism itself. But it 

 is certain that climatic conditions have not been the only, or even the 

 principal factors which have shaped out the range limits of any 

 particular species. Thus Cetonia aurata, the common Rose Chafer, is 

 in England quite a southern species, but in Ireland is found 

 abundantly as far north as Antrim and also in the Isle of Man. In 

 this second group I should also feel inclined to include most of our 

 fen insects, as well a species with so restricted a north-eastern range 

 as Nebria livida. 



I have already defined this group as one having a maximum 

 density in the south-east, and thinning out gradually north and west, 

 but we find several species in our fauna which we can hardly include 

 in such a definition. These are forms having a, very limited southern 

 or western range, and in some cases appearing merely as isolated 

 detachments in quite southern localities. 



All orders of insects supply examples of this group and among the 

 Coleoptera it will be sufficient to cite as examples Cicindda (jermanica, 

 Dromius vectensis or Oinophlns ariiieiiae in its eastern, and Rhopalo- 

 mesites tardiji or E.voiiiias pyrenaciis in its western extension. 



I have called the former the third and the latter the fourth division 

 into which I provisionally divided our coleoptera, but I am by no 

 means sure that they difier chronologically although they may have 

 done so in immediate origin and their separation is certainly a 

 matter of convenience. They are often so entangled with the second 

 group that the true allocation of many of their species seems impos- 

 sible and in all must be provisional on the extent of our knowledge or 

 rather our ignorance. Thus at Deal we find associated with the 

 Erodiion of the coast sandhills, fli/pera faaiculata and Li.vus bicolor, 

 but as the first occurs also in similar situations at Rhyl, and the latter 

 seems, so far as we know at present, almost restricted to the coast of 

 Kent, I should place the Hi/pcra in the second but the Li.vus in the 

 third group. 



The advent of these forms seems to have been subsequent to the 

 general settlement here of the second group, and its restrictions due 

 to the competition of an already established fauna. It is probable that 

 on the cessation of glacial conditions in Europe there was a general 

 northerly movement over the whole of the continental area, and that, 



