COLEOPTERA 



12 I 



These figures fully show the remarkable character of the Kauai fauna in this family 

 of Coleoptera. Not only is it considerably the richest in species, but the percentage of 

 peculiar species is much higher than is the case with any other island. Moreover the 

 species themselves are in many cases highly remarkable, as compared with those of the 

 same genus on the other islands. Thus in Oodewas, O. longirostre, O. costatnm, 

 O. striahan, O. pulchrum, are species of the most highly evoluted form, each in its own 

 particular direction. So also the Kauai species of Rhyncogonus form a remarkable 

 series. These facts suggest the probability that the ancestors of the now existing fauna 

 of Curculionidae may, at least to a large extent, have first gained a footing on this 

 island, possibly at a time when some of the more recent islands were not adapted for the 

 mode of life of these creatures, or possibly even before these islands existed at all. This 

 suggestion is strengthened by a consideration of the condition of the weevils on the 

 other islands ; thus Oahu comes second both in number of species and in the per- 

 centage of those peculiar to it, and it is noteworthy that a number of the most 

 remarkable forms are found in what yet remains of the once fine forest of the Waianae 

 range, itself one of the oldest portions of the whole group of islands. Very different is 

 the case with Hawaii, which from its large size, lofty mountains, and very varied climate, 

 as well as its position at the end of the series of islands, might be expected to have a 

 large number of remarkable forms. This however is not the case, for it is not only 

 altogether wanting in Rhyncogonus, Hetcramphus and Anotheot'us, but it possesses but 

 three or four species of Oodenias, and these of the most commonplace forms. In the 

 group we are now considering the condition of the fauna of the big island contrasts 

 curiously with its Aculeate Hymenoptera, which are both richly represented and 

 remarkable ; indeed it is not necessary to go beyond the order of Coleoptera to see a 

 similar contrast, for the indigenous Cerambycidae are well represented there and some 

 of the forms are amongst the most remarkable of those found in the group. 



Variation. We have already when dealing with the Aculeate Hymenoptera, 

 Neuroptera and Orthoptera remarked on the variability of so many of the island species. 

 Not less remarkable is this in the case of the Curculionidae. Mr Blackburn in describing 

 the species of Oodenias notes that their variability in certain points is embarrassing to 

 the describer, and with a large collection this becomes so much so, that in many cases 

 it is almost impossible to write a description which will apply in all respects to every 

 individual specimen. This variability too is not confined to superficial and trivial 

 characters, but affects those which are considered of decided importance for the separa- 

 tion of species. Even structures which are almost always constant vary in some species, 

 as for example parts of the prosternum in some species of Oodenias. We may observe 

 that there is no doubt as to the examples which exhibit this variability belonging to the 

 same species, and we are excluding from consideration such a species as O. niultifornie 

 of Hawaii, which may possibly include several allied and variable species; but is more 



