32 RIO DE JANEIRO. [CHAP. n. 



closing, and thus escaped. But a far more singular fact is the 

 power which this species possesses of making a noise.* Several 

 times when a pair, probably male and female, were chasing each 

 other in an irregular course, they passed within a few yards of me ; 

 and I distinctly heard a clicking noise, similar to that produced by 

 a toothed wheel passing under a spring catch. The noise was con- 

 tinued at short intervals, and could be distinguished at about 

 twenty yards' distance: I am certain there is no error in the 

 observation. 



I was disappointed in the general aspect of the Coleoptera. The 

 number of minute and obscurely coloured beetles is exceedingly 

 great.f The cabinets of Europe can, as yet, boast only of the larger 

 species from tropical climates. It is sufficient to disturb the com- 

 posure of an entomologist's mind, to look forward to the future 

 dimensions of a complete catalogue. The carnivorous beetles, or 

 Carabidse, appear in extremely few numbers within the tropics : 

 this is the more remarkable when compared to the case of the car- 

 nivorous quadrupeds, which are so abundant in hot countries. I 

 was struck with this observation both on entering Brazil, and when 

 I saw the many elegant and active forms of the Harpalidrc re- 

 appearing on the temperate plains of La Plata. Do the very 

 numerous spiders and rapacious Hymenoptera supply the place of 

 the carnivorous beetles? The carrion-feeders and Brachelytera 

 are very uncommon; on the other hand, the Khyncophora and 

 Chrysomelidee, all of which depend on the vegetable world for sub' 

 sistence, are present in astonishing numbers. I do not here refer 

 to the number of different species, but to that of the individual 

 insects; for on this it is that the most striking character in the 



* Mr. Doubleday has lately described (before the Entomological Society, 

 March 3rd, 1845) a peculiar structure iu the wings of this butterfly, which 

 seems to be the means of its making its noise. He says, " It is remarkable 

 for having a sort of drum at the base of the fore wings, between the costal 

 nervure and the subcostal. These two nervures, moreover, have a peculiar 

 screw-like diaphragm or vessel in the interior." I find in LangsdoriTs 

 travels (iu the years 1803-7, p. 74) it is said, that in the island of St. 

 Catherine's on the coast of Brazil, a butterfly called Februa Hoffinanseggi, 

 makes a noise, when flying away, like a rattle. 



t I may mention, as a common instance of one day's (June 23rd) col- 

 lecting, when I was not attending particularly to the Coleoptera, that I 

 caught sixty-eight species of that order. Among these, there were only 

 two of the Carabidso, four Brachelytra, fifteen Rhyncophora, and fourteen 

 of the Chrysornelidje. Thiity-seven species of Arachnicla), which I brought 

 home, will be sufficient to prove that I was not paying overmuch attention 

 to the generally favoured order of Coleoptera. 



