234 A NATURALIST IN BORNEO 



Other Bornean Longicorns mimic allies of the 

 weevils the Brenthidce, curious long-snouted, slender 

 beetles, generally cryptically coloured. Here again the 

 mimicry is brought about by simulation, not by imita- 

 tion. The Longicorns have the greater part of the 

 antennae clothed thickly with dense-set hairs, and they 

 are carried closely apposed and sticking straight out 

 in front of the head, the terminal joints diverging. 

 They thus offer a sufficiently close resemblance to the 

 rostrum of the Brenthidce to be very deceiving. Such 

 an example is quite enough to confute the argument 

 that mimetic resemblances are due to similarity of 

 conditions. Why should similar conditions produce a 

 rostrum in one beetle and furry antennae simulating 

 a rostrum in another ? One other fact may be noted : 

 some of the Brenthidce t which belong to the genus 

 Diurus, are streaked or speckled with pale ochreous, 

 and if one of them be carefully examined with a lens 

 it will be seen that the pale colour is due to little 

 ochreous scales, rather like miniature cartridge wads, 

 set in deep punctures which are seriately arranged. 

 The mimicking Longicorns, ^Egoprepis insignis and 

 Ectatosia morei, are also speckled with pale ochreous, 

 but in these beetles the speckling is produced by 

 small tufts of recumbent hairs on the elytra and 

 thorax. So is illustrated once again the fact that a 

 similar appearance may be produced by quite different 

 means. 



Six Longicorns belonging to three sub-families of the 

 Lamiida, viz. Mesosince, Hippopsince, and Agniince, mimic 

 the Brenthidce. Two of these, Alibora sp., and Elelea 

 concinna, mimic respectively Baryrrhynchus dehiscens and 

 Arrhenodes sp., which are rich chestnut Brenthids with 



