chap, x.] THE PAL^ARCTIC REGION. 197 



Trechus and Peryphus being especially characteristic. Staphy- 

 linidse abound. Among Lamellicorns the genus Aplwdius is 

 most characteristic. Buprestid.se are scarce ; Elateridee more 

 abundant. Among Malacoderms Telephorus and Malachius are 

 characteristic. Curculionidse abound : Otiorhyuchus, Omias, 

 Erirhinus, Bagous, Rhynchites and CeutorhyncJms being very 

 characteristic genera. Of Longicorns Callidium, Dorcadion, 

 Pogonochcerus, Pachyta and Leptura are perhaps the best re- 

 presentatives. Donatio, , Crioceris, Chrysomela, and Altica, are 

 typical Phytophaga; while Coccinella is the best representa- 

 tive of the Securipalpes. 



North European Islands. — The British Islands are known to 

 have been recently connected with the Continent, and their 

 animal productions are so uniformly identical with continental 

 species as to require no special note. The only general fact of 

 importance is, that the number of species in all groups is much 

 less than in continental districts of equal extent, and that this 

 number is still farther diminished in Ireland. This may be 

 accounted for by the smaller area and less varied surface of the 

 latter island ; and it may also be partly due to the great extent 

 of low land, so that a very small depression would reduce it 

 to the condition of a cluster of small islands capable of sup- 

 porting a very limited amount of animal life. Yet further, if 

 after such a submergence had destroyed much of the higher 

 forms of life in Great Britain and Ireland, both were elevated so 

 as to again form part of the Continent, a migration would com- 

 mence by which they would be stocked afresh ; but this migra- 

 tion would be a work of time, and it is to be expected that 

 many species would never reach Ireland or would find its exces- 

 sively moist climate unsuited to them. 



Some few British species differ slightly from their continental 

 allies, and are considered by many naturalists to be distinct. 

 This is the case with the red grouse (Lagopus scoticus) among 

 birds ; and a few of the smaller Passeres have also been found 

 to vary somewhat from the allied forms on the Continent, show- 

 ing that the comparatively short interval since the glacial period, 

 and the slightly different physical conditions dependent on 



