THE CHIEF COLEOPTEnOUS FAUNAE. • 40 



maire iu hia « Monograph on the Coleoptera of Polynesia" (Rev. 

 Zool. 1849-50) :— « In general, the Coleoptera of Polynesia have a 

 facies by no means equatorial .- although living under a burning 

 sky, in the midst of a luxuriant and always growing vegetation, 

 their colours are sad, and their bodies do not exhibit the large 

 size, the varied form, the metallic lustre which we admire iu the 

 Coleoptera of New Guinea and the East Indies. A Buprestid of 

 tolerable size, Chrysodema Tayauti, almost alone represents that 

 tribe so numerous in New Holland and New Guinea ; the Chryso- 

 melidae are reduced to two or three insignificant species" (Eev. 

 Zool. 1849, p. 279). 



So much for the facies. The actual relationship of the mate- 

 rials composing it is shown in a Table in the Appendix, which I 

 have made up from M. Fairmaire's work above cited, and in 

 which I have marked the distribution of the different genera com- 

 posing it. 



From these it will be seen that not only a very large prepon- 

 derance are of microtypal form, but that the fauna contains many 

 genera which are familiar to the British entomologist as especially 

 characteristic of the British subfauna, such as the gen&cd. Anchome- 

 nus, Bembidium, Colymhetes, Agabus, BolitOchara, Placusa, Sunim, 

 Leichenum, AnthicuS, Ditoma, Cicones, Cerylon, Bhizophagm, &c. 

 The forms which have been borrowed from non-microtypal regions 

 are not numerous ; and there is no difficulty in indicating their 

 source, the species being in many cases identical with that of the 

 country from which it has come, a very common thing with intro- 

 duced species, and which does not occur here with the microtypal 

 species. In them the genus is the same, but the species is changed 

 into new ones. It is this difference between recent immigrants and 

 long-descended natives which generally renders lists of the distri- 

 bution of mere species of so little value. They tell the tale of close 

 vicinity, which we usually know without them, and of chance in- 

 troductions, which throw no light on geographical phenomena ; 

 whereas lists of the distribution of genera speak of forms origi- 

 nally the same, but broken into new species by subsequent sepa- 

 ration ; and by their affinities we can trace their history much 

 further into the past. In this concatenation the multiplication of 

 genera on slight grounds is a serious obstacle to the study of geo- 

 graphical distribution. It injures it not merely by overburden- 

 ing the memory with unnecessary names, but mainly by depriving 



LINN. PROC. — ZOOLOGY, TOL. IT. 4 



