374 THE CANADIAN ENTOMOLOGIST 



II. Insects with six feet. 



Without wings. 



a With organs of motion like feet {Thysanura). 

 b Mouth with a retractile sucker {Parasita) . 

 c External mouth with a jointed tube enclosing a sucker 

 {Suctoria) . 



With four wings. 



A Upper wings crustaceous or coriaceous, at least at the 

 base. 



a With under wings folded crosswise — beetles (Coleop- 

 tera) . 



1, Pentamera; 2, Heteromera; 3, Trimera; 4, Tetra- 

 mera). 



1) With under wings folded lengthwise (Orthoptera). 



Legs formed for running (Cursoria). 

 ' Legs formed for leaping {Saltatoria) . 

 V. With sucker enclosing several bristles (Heniiptera). 



1, Heteroptera; 2, Homoptera. 



Upper wings membranaceous. 



a Wings naked and nettled (Neuroptera) — 1, Subuli- 

 cornes; 2, Planipennes; 3, Plicipennes. 



b Wings naked and veined (Hymenoptera) — 1, Tere- 

 brantia; 2, Aculeata. 



c Wings with dust-like scales (Lepidoptera) — 1, Diurna; 

 2, Crepuscularia; 3, Nocturna. 



With two twisted elytra and two wings {Rhipiptera) — 

 1, Xenos; 2, Stylops. 



With two wings {Diptera). 



Latreille also wrote a paper on the Geography of Insects in 

 which he divided the globe into twelve insect zones. His two main 

 divisions were Arctic (all north of the equator) and Antarctic (all 

 south of the equator). The Arctic was sub-divided into the Polar, 

 sub-Polar, Superior, Intermediate, Supra-tropical, Tropical and 

 Equatorial, while the Antarctic embraced the Equatorial, Tropical, 

 Supra-tropical, Intermediate and Superior. 



