604* EXTERNAL ANATOMY OF INSECTS. 



more dark and dismal aspect and colour than those which 

 feed upon such as are living and fresh, denominated thale- 

 rophagous by the same learned author ; this you may see 

 exemplified in his Scarabcsidce and Cetoniadce. Again, in 

 the Predaceous beetles a smilar contrast of colours is often 

 observable. How brilliant and gay are the fierce Cicindelce ! 

 those tigers of insects, as Linne calls them ; how black 

 as to colour, how horrible in aspect is their near relation 

 the Manticora : what difference exists in the economy of 

 these animals is not known, except, as I learn from Mr. 

 Burchell, that the latter is subterraneous, whereas the 

 former seek the sunbeam and fly rapidly. I shall now 

 point out a few instances in which the colours of their 

 elytra distinguish tribes or families. Amongst the Pre- 

 daceous beetles a large family of the Cicindelidce are 

 distinguished by a middle angular white band, and se- 

 veral white dots on their green or brown elytra, as in 

 C. sylvatica ; a family of Brachinus, and the majority 

 of Mylabris, Lamia capensis and fasciatus, &c, by 

 black elytra, with yellow or red bands ; Carabus violacea 

 and affinities by the violet margin of these organs ; Cal- 

 liochroma Latreille by their sericeous, and Eumolpus by 

 their metallic, lustre. These instances will be sufficient 

 to turn your attention to this subject, which though not 

 of primary importance in discriminating genera &c, is 

 not without its use in a secondary view. 



10. Uses. I must not quit this subject without saying 

 something upon the ends which elytra seem designed to 

 serve. Their first and most obvious use is the protection 

 of the wings when unemployed, that they may not be 

 lacerated or soiled, and rendered unfit for flight in the 

 various retreats to which these animals betake themselves 



