COLLECTION OF ARTICULATED ANIMALS. 497 



terminated by the genus aphis, or plant louse, 

 which lives upon the leaves and tender shoots of 

 plants and trees. 



The next order, that of the dlptera, compre- 

 hends the musca, the culex, the tipula', the ta- 

 banusy the oestrus, and a great number of other 

 genera , not remarkable either in form or co- 

 lour, but \vhose history is nevertheless worthy 

 of attention. The gnats or musquitoes and the 

 tabani are the scourges of men and domestic 

 animals in hot countries ; it is with difficulty 

 that we preserve our meat from the flies which 

 lay their eggs in it ; the gadflies lay theirs on se- 

 veral parts of cattle ; the cestrus bovinus (n 5) 

 attacks them, and draws blood by its bite ; the 

 ce. maroccanus (n 7) torments the dromedary. 

 The bombflii, like several other lepidoptera, 

 hover around flowering plants, making a hum- 

 ming noise. The stratiomides are distinguished 

 by their spiny scutellum ; their larvae, which are 

 aquatic, as well as those of several syrphi, respire 

 through the posterior extremity of their body, 

 which has the form of a tube, and is shortened 

 or lengthened by the insect at will. We cannot 

 enter into more ample details, nor particularize 

 a greater number of species; we shall content 

 ourselves therefore with observing, that to the 

 iipulce belong those numerous swarms of flies 





