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ground on which they rest. We need only mention such 

 genera as Batocera, Saperda, and Lamia among the Longi- 

 corns, and Brachycerus and Lithinus among the weevils ; the 

 species of the latter genus, L. superciliosus, L. penicillatus, 

 and L. nigrocristatus (all from Madagascar) are usually con- 

 sidered to be typical instances of resemblance to surroundings : 

 the last-named species so closely resembles the lichen-covered 

 twigs on which it lives that it can hardly be detected by an 

 unpractised eye, even when its position is pointed out, and 

 another Madagascar genus Rhytidophloeus is almost as well 

 concealed : we find almost the same facies in the Longicorn 

 genera Des?nophora, from South America, and Onychocerus 

 also closely resembles lichen ; but perhaps the closest resem- 

 blance to this is afforded by the members of the Homopterous 

 genus Flatoides : the bodies of these are concealed by the 

 tegmina, which are formed as in Cassida, but the upper 

 surface is so marked and moulded that the insects exactly 

 resemble a piece of lichen, or lichen growing round bark : 

 several members of the Elaterid genera Iplds and Alaus are 

 so coloured as to resemble bark, and the same to a less degree 

 might be said of members of other groups. Conspicuous 

 colouring, moreover, is not necessarily aposematic or " warn- 

 ing " : it may be pre-eminently cryptic when seen in its 

 proper surroundings : in the case of the sombrely-coloured genus 

 Prosopocera from East Africa we find among the dull brownish 

 species a conspicuous insect, P. alboplagiata, which is probably 

 well protected in its natural environment, and the same is 

 true of certain species of Coptops. In 1851 Francis Galton 

 wrote as follows:* — "No more conspicuous animal can well 

 be conceived, according to common idea, than the zebra : but 

 on a bright starlight night the breathing of one may be heard 

 close by you, and yet you will be positively unable to see the 

 animal. If the black stripes were more numerous he would be 

 seen as a black mass : if the white, as a white one : but their 

 proportion is such as exactly to match the pale tint which arid 

 ground possesses when seen by moonlight " : in connection 

 with this statement, it is worth mentioning that there is a 



* Galton's "South Africa" (Minerva Library), p. 187 : quoted by Poulton, 

 "The Colours of Animals," p. 25. 



