THE WING SYSTEM. 441 



De Geer. Aristotle does not, indeed, pnt his system in a 

 tabular form ; but, for the sake of brevity, we shall draw 

 up a table, founded on indications in his admirable History 

 of Animals. 



Aristotle s Classification. 

 I. Winged Insects (Pterota, Ptilota). 



1. With wing-cases — beetles — (Coleoptera). 



2. With coriaceous wings— grasshoppers (Pedetica). 



3. Without jaws— bugs (Astomata). 



4. With powdery wings — moths and butterflies (Psychx). 



5. With four transparent wings (Tetraptera). 

 Without stings, and larger — dragon-flies. 

 With stings — bees and wasps ( Opisthocentra). 



6. With two wings (Diptera). 



Without mouth-piercers, and smaller— flies and crane-flies. 

 With mouth-piercers— gnats and gad-flies (Emprosthocentra). 



II. Wingless Insects. 



1. Occasionally acquiring wings : — 

 Ants (Myrmices). 

 Glow-worms ( Pygolampides). 



2. Without wings (Aj^tera). 



L innxuss Classification, 



I. Winged Insects, 



1. With four tvings : — 



a, Upper wings more or less crustaceous : the under wings 



membranaceous. 

 Upper wings quite crustaceous, and not overlapping— 



beetles (Coleoptera). 

 Upper wings semi-crustaceous, and overlapping — bugs and 



gi-asshoppers (Hemiptera). 



b, Upper and under wings of the same textm-e. 



Wings covered with small tiled scales — butterflies and 



moths (Lepidoptera). 

 Wings membranaceous and naked. 



Without a sting — dragon-flies, &c, (Neuroptera). 



With a sting — wasps, bees, &c, ( Hymenoptera). 



2. With two wings : — Flies, gnats, &c. (Diptera). 



II. Wingless Insects (Aptera). 



Be Geers Classification. 

 1. Winged Insects. 



1. Wings four, without iving-cases : — ' 



a. Wings covered with scales ; tongue spiral— butterflies and 

 moths. 



