11 



formis for a species which, when sitting upon a tree, will not 

 only look exactly like a hornet, but actually raise its abdo- 

 men in a most menacing manner as though prepared to sting 

 on the smallest provocation. The resemblance in all the 

 species of this group to species of Hymenoptera is indeed 

 most wonderful. 



Scarcely less striking and interesting is the imitation of 

 dead leaves by the various species of stout-bodied Bombyces 

 of the genera Gastropacha, Odonestis, Lasiocampa, Erio- 

 gaster, etc., when at rest. What can be more remarkable than 

 a sitting specimen of Gastropacha quercijolia, with antennae 

 closely tucked away, the costa of the fore-wing on each side 

 forming, apparently, the midrib of the brown leaf, of which 

 the veins are represented by the brown nervures of the fore- 

 wing on the one side, while the protruding " lappet " of the 

 hind-wing finishes off the other side of the leaf. Little less 

 accurate in the resemblance to a paler leaf is a female Odonestis 

 potatoria when she elects to hang from a grass blade under a 

 hedge ; while in the case of the rare Gastropacha ilicifolia it 

 is notorious that the captor of the first British specimen would 

 not have seen it at all had he not fortunately knelt down 

 close to it to pin a small Tortrix ; then he noticed that what 

 appeared to be a dead leaf was altogether too symmetrical, 

 and was in fact a living and most lovely moth. 



The close resemblance of Hemerophila abruptaria to the 

 paling on which it loves to spread itself flat, like a chip, has 

 also been noticed, and the general likeness of many of the 

 Eupithecm to weather-stained palings and the bark of trees, 

 has not escaped observation ; though it is not perhaps very 

 generally known that many of them may be found in plenty, 

 if the eye is keen enough to discern them, on the underside 

 of branches of trees, squeezed close to the bark, and hardly 

 distinguishable. The accurate adaptation of various Noctucs, 

 of GeoinetrcB of the genera Cleora, Boarntia, Tephrosia, 

 Ctdaria, and others, and of Pcedisca, Phlaodes, etc., among 

 the Tortrices, to all sorts of positions on tree trunks and 

 branches, is familiar to us all ; while many Tortrices of the 

 genera Penthina, Antithesza, Spilonota, Halonota, etc., have 

 actually received the nick-name of "bird's-dung Tortrices,"^ 

 from their extraordinary resemblance to the excrement of birds. 



My present intention is not so much to draw attention to 

 the well-known general resemblances, as to point out special 

 cases in which the actual imitation is peculiarly close, or where 

 from a singular harmony of colour and marking, an effect 

 is produced, deceptive to the eye, which would not, from the 



