THE ECLECTIC, OR MODERN SYSTEM. 440 



II. Insects with Six Fket. 

 Without icings : — 



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 loings : — 



A, Upper wings crustaceous or coriaceous, at least at the base. 

 a. With the under wings folded crosswise— beetles (Coleoptera). 



1. Pentamcra ; 2. Heteromera ; 3. Tetramera ; 4. Trimera. 

 h, With the under wings folded lengthwise (Orthoptera). 



Legs formed for running ( Cursor ia). 

 Legs formed for leaping (Saltatoria). 

 c, With a sucker enclosing several bristles (Hemiptera). 1 

 Heteroptera; 2. Homoptera. 



B, Upper wings membranaceous. 



a. Wings naked and netted ('iVeiiropfera J. 1, Subulicornes ; 2. 



Planipennes ; 3. Plicipennes. 

 h. Wings naked and veined (Hymenoptera). 1. Terebrantia ; 



2. Aculeata. 



c, Wings with dust-like scales (Lepidopiera). 1. Diurna; 2. 



Crepuscularia ; 3. Nocturna. 

 With two twisted elytra and two wings ^EliipipteraJ). 1. Xenos ; 



2. Stylops. 

 With two wings (Diptera). 



Leach's Classification. 

 I. Insects undergoing no Transformation (Ametaholia). 



1. With bristles at the tail (Thysanura). 



2. With no bristles at the, tail (Anop>lura). 



II. Insects undergoing Transformation (Metaholia). 



1. With two wings folded crosswise, and covered with hard wing- 



cases (Coleoptera). • 



2. With two wings folded lengthwise and crosswise, and short and 



softer wing-cases (Dermaptera). 



3. With two wings folded lengthwise, and wing-cases overlapping 



each other at the edges (OrthopAera). 



4. With two wings twice folded lengthwise, and wing-cases obliquely 



overlapping; mouth with jaws (Dictyoptera). 



5. With two whigs, and overlapping wing-cases, having the apex 



membranaceous (Hemiptera). 

 0. With two wings, and coriaceous or membranaceous wing-cases 



(Onio2)tera). 

 7. With no wings nor wing-cases (Aptera). 



2g 



