LINN.EAN GENERA LUCANUS AND HISTER. 31 



then in the possession of entomologists. But the value of 

 De Geer's observations is now estabhshed, since Fabricius 

 and his followers have proved that the nature and manners 

 of the insect bear an immediate relation to the form and 

 texture of its organs of manducation. In the same way 

 there will be found in this chapter several remarks on the 

 KecUcera, which, though by no means new, will neverthe- 

 less be shown to deserve greater attention than they have 

 hitherto obtained. 



It may in general be observed of the Rectacera, or In- 

 secta herbivora, petitamera, antenuis quasi fractis, that 

 Nature seems to have dispersed them over the globe much 

 more sparingly than the Petalocera ; the truth of which 

 will appear from the inspection of any extensive entomo- 

 logical collection. They will however be found to branch 

 off like the Petalocera into two columns, the one of sa- 

 prophagous insects, composingLinnfeus's genus Hister, and 

 the other of thalerophagous insects, being the same with 

 his Lucamis: and it is worth the noticing, that as both 

 circles of the Petalocera seem to contain about the same 

 number of species, so there is somethmg like equality per- 

 ceptible in the contents of the columns of Saprophagous 

 and Thalerophagous Rectacera. 



As the Rectacera are few in number, and these few are 

 but imperfectly known, it can hardly be a matter of sur- 

 prise that we should not here perceive the infinite grada- 

 tions of construction which render ihe filiation of Nature 

 among the Petalocera comparatively easy to be seized. — 

 A considerable hiatus accordingly often occurs among the 

 Rectacera: but that there is no reason to conclude that 

 insects do not exist to fill up such chasms, I shall prove by 

 the description (in the Appendix) of some new insects be- 



