1 86 FAUNA HAWAIIENSIS 



from different origins by some agencies we do not understand. Should these examples 

 — as we suppose many other Hawaiian Carabidae have done — lose their setae, it would 

 then be a difficult matter to distinguish the species, and many entomologists would 

 declare them all to be one. 



Had I not adopted the condition of the wings and the thoracic setae as a basis for 

 genera our Hawaiian Carabidae would have appeared as members of only three or four 

 genera. The other structural characters I have used for discrimination are extremely 

 slight. This should be borne in mind, as the picture thus presented of three distinct 

 groups, each consisting of a considerable number of closely allied forms, is fairly correct. 



There are one or two points of a general nature that may be noticed. The 

 Hawaiian Carabidae are as a whole considerably below the average in stature ; the 

 largest form — Barypristtis incendiarhis — is scarcely so large as our Pristonychus terricola ; 

 and small forms predominate. The Bembidiids are on the average smaller than our 

 European forms, and there is not a single instance of a form that is large for the group 

 to which it belongs. Fine colours and elegant shapes are extremely rare, but there are 

 examples of remarkable sculpture. 



The fore-feet of the male are much less developed than usual. Their dilatation is 

 so slight that it can generally scarcely be detected. The Bembidiids form to some 

 extent an exception to this ; but this group is one in which this character is everywhere 

 inconspicuous. 



Variation. That the Hawaiian Carabidae are variable is quite certain. To what 

 extent they are variable in compari.son with their analogues in other faunas is however 

 a very difficult question. There are certain reasons that incline one to estimate too 

 highly the variability of Hawaiian forms. In studying European beetles we have all 

 sorts of books to help us, and these have been so drawn up as to put on one side the 

 variable characters and draw our attention to those that are comparatively stable. In 

 the Hawaiian fauna this is not yet the case. We have to look at everything, and unless 

 one has a long series, it is very difficult to form an opinion as to the stability of the 

 characters observed. After making allowance for this, and for the various isolated 

 forms that are easily distinguished on one or two specimens, I think that as a whole the 

 Hawaiian Carabidae are really more variable than the European. 



There are many very variable species in Europe — protean they are frequently 

 called — but I think the proportion of these is greater in Hawaii than in Europe. Some 

 Hawaiian species are but little variable so far as extant evidence goes. The two species 

 of Deropristns, D. pjnicticeps and D. deroderns, vary but little if I may judge from the 

 lOO examples I have seen. Metromemis pavidus, of which I have seen 240 specimens, 

 shows but little variation. But it must be recollected that our specimens come from 

 but few localities, and the variation might be greater if the area of the distribution were 

 more thoroughly scrutinised. Whether there is anything in Hawaiian species to corre- 

 spond to the geographical variation one finds in European forms ; or whether that 

 geographical variation has become accentuated, so as to form species, by the separation 



