COLLECTION OF ARTICULATED ANIMALS. 497 



terminated by the genus aphls 7 or plant louse, 

 which lives upon the leaves and tender shoots of 

 plants and trees. 



The next order, that of the diptera, compre- 

 hends the muse a, the culex, the tipula, the ta- 

 baniiSy the cestrus, and a great number of other 

 genera , not remarkable either in form or co- 

 lour, but whose history is nevertheless worthy 

 of attention. The gnats or musquitocs 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 bombflil ? like several other lepidoptera, 

 hover around flowering plants, making a hum- 

 ming noise. The straiiomides 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 

 lipulce belong those numerous swarms of flies 



5a 



