MEANS OF DEFENCE OF INSECTS. 255 



guished, by the predaceous aquatic insects, from the soil 

 on which it rests. Another very minute insect of the 

 same order (Limnius ceneus} that is found in rivulets 

 under stones and the like, sometimes conceals its elytra 

 with a thick coating of sand, that becomes nearly as hard 

 as stone. I never met with these animals so circum- 

 stanced but once; then, however, there were several 

 which had thus defended themselves, and I can now 

 show you a specimen. A species of a minute cole- 

 opterous genus (Georyssus areniferus*), which lives in 

 wet spots where the toad-rush (Juncus bufonius) grows, 

 covers itself with sand ; and another nearly related to 

 it (Chcetophorus cretiferus^ K.) which frequents chalk, 

 whitens itself all over with that substance. As this ani- 

 mal, when clean, is very black, were it not for this ma- 

 noeuvre, it would be too conspicuous upon its white ter- 

 ritory to have any chance of escape from the birds and 

 its other assailants. No insect is more celebrated for 

 rendering itself hideous by a coat of dirt than the Re- 

 duvius personatus, a kind of bug sometimes found in 

 houses. When in its two preparatory states, every part 

 of its body, even its legs and antennae, is so covered with 

 the dust of apartments, consisting of a mixture of par- 



a In the former Editions of this work this insect was stated to be 

 synonymous with Trox dubius of Panzer, which it much resembles, 

 except in the sculpture of the prothorax, (Fn. Ins. Germ. Init. Ixii. 

 t. 5.) ; but as Schonherr and Gyllenhal, who had better means of 

 ascertaining the point, regard Georyssus pygmteus, Latr., as Panzer's 

 insect, the reference is now omitted. G. areniferus differs conside- 

 rably from G. pygmceus, as described by Gyllenhal (Insect. Suec. I. iii. 

 675.) The front is not rugulose, the vertex is channeled, the an- 

 tennae shorter than the head; the prothorax is rather shining, mark- 

 ed anteriorly with several excavations, in the middle of which is a 

 channel forming a reversed cross with a transverse impression. 



