FAMILIiE. 125 



in another. By pursuing this method, however, 

 I got my species into some order, and they were 

 arranged, the above great mistake excepted, very 

 nearly according to their natural affinities. I then 

 proceeded to examine the proboscis, and external 

 anatomy of those which were found to agree in 

 habit, and by this method I soon arrived at their 

 distinguishing characters, and was enabled to de- 

 tect those marks, exclusive of the organs of gene- 

 ration, which are the constant characteristics of 

 the males in these genera. I found that some of 

 those insects which I had considered as belonging 

 to distinct families, had invariably one joint more 

 in their antennae, and generally one segment more 

 in their abdomen than others (wi), that their bodies 

 were proportionably narrower, and their antennae 

 and legs longer and more slender. It soon occur- 

 red to me that these were only sexual distinctions^ 

 an idea which was confirmed by pressing the anus 

 of such as I had an opportunity of taking alive, and 

 inspecting their genitalia. The mistake above 

 alluded to was in this manner rectified; and, in- 

 stead of confusion, lucid order now took place in 

 my arrangement. Thus, beginning with habit and 



(vi) Both these circumstances, with respect to some indivi- 

 duals in this class, have been noticed by De Geer, but he did 

 not follow up this discovery, and examine whether it would 

 hold good in the whole genera. My observations were made 

 before I was aware that this illustrious author had made the 

 above discovery, De Geer_, 2. p. 2. pp. T/'l. 7gfi. S17- 



ending 



