EXTERNAL ANATOMY OF INSECTS. 661 



6. Clothing. The hairs on the legs of insects, though 

 at first sight they may seem unimportant, in many cases 

 are of great use to them, both in their ordinary avocations 

 and motions : but as most of these were sufficiently no 

 ticed when I treated of the sexes of insects a , I shall not 

 here repeat my observations, but confine myself to cases 

 not then adverted to. Some insects have all their legs very 

 hairy, as many spiders, the diamond beetle (Entimus im- 

 perialist, or at least a species very near it and common 

 in Brazil 15 , &c: in others they are nearly naked, as in 

 the stag-beetle. In the Crepuscular Lepidoptera [Sphinx 

 L.) and some of the Nocturnal ones [Bombyx L.) the 

 thighs are much more hairy than the rest of the legs : 

 and in Lucanus, Geotrupes, and many other Lamellicorns, 

 &c, the anterior ones have a yellow or golden spot at 

 their base, composed of decumbent hairs, which prevent 

 them from suffering by the violent friction to which they 

 are exposed in burrowing. In most Petalocerous beetles 

 the tibiae are set with scattered bristles, and sometimes 

 the thighs. The Tiger beetles (Cicindela) are similarly 

 circumstanced: but the bristles, which are white, are ge- 

 nerally arranged in rows. In Dytiscus, Hydrophilus, &c, 

 the four posterior tarsi ; and in Notonecta the posterior 

 pair, and also the tibiae — are fringed on each side with a 

 dense series of hairs, which structure assists them in 

 swimming c . The tarsi, especially the anterior pair, in a 

 certain family of Lamia F. (L. papulosa, &c. d ), are simi- 

 larly fringed, only the hairs curl inwards ; and the hand 



a See above, p. 305 — . b This variety appears to differ 



very little from the Curcutio imperialis of Fabricius and Olivier, ex- 

 cept in the remarkable hairiness of its legs. c Vol. II. p. 563, 



d Oliv. Ins. n. 67- t. xx.f. 156. 



