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

;228 ZOOLOGICAL GEOGRAPHY. [part hi.Coleoptera.—The beetles of Japan decidedly exhibit a mixtureof tropical forms with others truly Palsearctic, and it has beenwith some naturalists a matter of doubt whether the southern andbest known portion of the islands should not be joined to theOriental region. An important addition to our knowledge ofthe insects of this country has recently been made by Mr. GeorgeLewis, and a portion of his collections have been described byvarious entomologists in the Transactions of the EntomologicalSociety of London. As the question is one of considerable interestwe shall give a summary of the results fairly deduciblefrom what is now known of the entomology of Japan ;and itmust be remembered that almost all our collections come fromthe southern districts, in what is almost a sub-tropical climateso that if we find a considerable proportion of Palsearctic forms,we may be pretty sure that the preponderance will be muchgreater a little further north.Of Carabidae Mr. Bates enumerates 244 speciesbelonging to84 genera, and by comparing these with the Coleoptera of atract of about equal extent in western Europe, he concludes thatthere is little similarity, and that the cases of affinity to the formsof eastern tropical Asia preponderate. By comparing his generawith the distributions as given in Gemminger and Harold'sCatalogue, a somewhat different result is arrived at. Leavingout the generic types altogether peculiar to Japan, and also thoseo-enera of such world-wide distribution that they afford no clearindications for our purpose, it appears that no less than twentytwogenera, containing seventy-four of the Japanese species, areeither exclusively Palsearctic, Palsearctic and Nearctic, or highlycharacteristic of the Palsearctic region ; then come thirteen generacontaining eighty-seven of the species which have a very widedistribution, but are also Palsearctic : we next have seventeen^enera containing twenty-four of the Japanese species which aredecidedly Oriental and tropical. Here then the fair comparisonis between the twenty-two genera and seventy-four species whoseaffinities are clearly Palsearctic or at least north temperate, andseventeen genera with twenty-four species which are Asiaticand tropical; and this seems to prove that, although South