336 INSECT-ADAPTATIONS. 



possessed by some of their consimilars. Most of the 

 Crustacea would appear, on a careful comparison, to have 

 very distinct analogies with the families of Arachnidans. 



The nimble-limbed Dolomedes, that run after their 

 prey, and catch them by swiftness of foot, rather than by 

 stratagem, have slender legs, and, living on the ground, 

 are generally of dingy colours ; with the exception, how- 

 ever, of those very large and powerful species, which, if 

 not rendered somewhat conspicuous to the sight of other 

 insects, might do too much damage to the tribes they are 

 destined to keep in check ; most of these, therefore, have 

 the thorax and abdomen margined with 'a light colour, 

 that contrasts strongly with that of their bodies. The 

 Saltici generally resemble, more or less, the colour of the 

 places they inhabit. I noticed a species among the 

 dense thickets, formed by Abrus precatoria and other 

 trees, with a black abdomen, marked on each side with 

 dull scarlet, curious as being the colours of the seeds 

 of Abrus, which are called by children " black-a-moor 

 beauties ;" those species that live on the bark of trees are 

 mottled grey and brown, and those which you find upon 

 the ground, are altogether black or dingy coloured. 



It is an interesting fact, that those gay insects, which 

 love to sun themselves in the open parts of the forests, 

 exposed to view upon the leaves, like the brilliant Bupres- 

 tidce, and other splendid beetles of the tropics, are 

 glorious in their hues, while dingy-coloured Coleoptera, 

 like the Helluo, in his funereal dress, hide in obscure 

 holes and corners, where the sight may never reach them. 

 The Necrophagous Silphida, again, are most commonly 

 of obscure colouring, and conceal their dingy bodies in 



