Il6 GENERA. 



Aculeus valvis duabus, vaglnaque 

 univalvi spicula duo exerente, 



constans(^''). 



When I first turned my attention to the subject 

 of these pages, I thought of denoting all the species 

 described in them by one generic character : but 

 the more I studied them, the more strongly was I 

 convinced that they belonged to two natural ge- 

 nera, essentially distinguished from each other ; 

 and this idea was further confirmed, when I found 

 that Reaumur, and after him De Geer, had adopted 

 the same opinion ; although they did not sufficiently 

 extend the limits of the genus, which they deno- 

 minated Proaheille, for the insects that may be 

 arranged under it are equally numerous with the 

 genuine Apes. The characters which form the 

 most striking distinctions of these two genera are 

 furnished by the tongue; which organ, in the one, 

 is short, flattish, usually acute with a lateral auricle, 

 and not inflected; and in the other, elongate, 

 slender, cylindrical, and inflected. The first of 

 these distinguishes the Proabeilles, or Apes minus 

 proprie dictce ; and the other such as are genuine 

 Apes. 



De Geer has given the name of Nomada to those 

 insects which, after Reaumur, he separated from 



( h ) Liniieus, in his essential character of tlie genus Formica, 

 calls their aculeus obsolete. De Geer represents the species of 

 his first family as having no aculeus, and those of his second as 

 armed with that instrument, Tom. 2, P'^ 2. Mem. 18. 



Apis : 



