The geographical distribution of animals, with a study of the relations ...

chap, x.] THE PAL^ARCTIC REGION. 197Trechus and Peryphus being especially characteristic. Staphylinidaeabound. Among Lamellicorns the genus Aphodius ismost characteristic. Buprestidse are scarce ; Elateridse moreabundant. Among Malacoderms Telephones and Malachius arecharacteristic. Curculionidse abound : Otiovhyuchus, Omias,Erirhinus, Bagous, Rhynchites and Ceutorhynchus being verycharacteristic genera. Of Longicorns Callidium, Dorcadion,Pogonocficerus, Pachyta and Leptura are perhaps the best representatives.Donacia, Crioceris, Chrysomela, and Attica, aretypical Phytophaga; while Coccinella is the best representativeof theSecuripalpes.Forth European Islands.—The British Islands are known tohave been recently connected with the Continent, and theiranimal productions areso uniformly identical with continentalspecies as to require no special note. The only general fact ofimportance is, that the number of .species in all groups is muchless than in continental districts of equal extent, and that thisnumber is still farther diminished in Ireland. This may beaccounted for by the smaller areaand less varied surface of thelatter island ; and it may also be partly due to the great extentof low land, so that a very small depression would reduce itto the condition of a cluster of small islands capable of supportinga very limited amount of animal life. Yet further, ifafter such a submergence had destroyed much of the higherforms of life in Great Britain and Ireland, both were elevated soas to again form part of the Continent, a migration would commenceby which they would be stocked afresh ; but this migrationwould be a work of time, and it is to be expected thatmany species would never reach Ireland or would find its excessivelymoist climate unsuited to them.Some few British species differ slightly from their continentalallies, and are considered by many naturalists to be distinct.This is the case with the red grouse (Lagopus scoticus) amongbirds ;and a few of the smaller Passeres have also been foundto vary somewhat from the allied forms on the Continent, showingthat the comparatively short interval since the glacial period,and the slightly different physical conditions dependent on