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merely to afford sufficient space for the motion of the under wings, 
as they do not in the least accelerate the flight of the insect. 
They are either, 
Truncata, truncated, or cut off in a direct line at their extremity. 
Fastigiata , when of equal or greater length than the abdomen, 
terminating in a transverse line. 
Spinosa , spinous, with sharp, or obtuse elevations. 
Serrated , or with the outer margin armed with teeth like a saw. 
Their surface is either, 
Scabra , scabrous, rough. 
Striata , striated, with small longitudinal furrows. 
Porcata , porcated, or ridged longitudinally. 
Sulcata , sulcated, with deep furrows. 
Punctata , or marked with distinct spots. 
Hemelytra , when their substance is more compact, and stronger 
than the under ones. 
The halteres, or poizers, which are formed of a small head at the 
end of a stalk, are peculiar to the Dipterous, or two- winged insects, 
and are supposed to assist in giving an equilibrium to their bodies 
when flying. 
Cauda, the tail, in general is simple, and capable of extension and 
contraction. It is either, 
Setacea , bristle-shaped, as in the raphidia. 
Triseta, forming three bristles, as in some of the ephemera. 
Furcata , forked, as in the podura. 
Forcipata , like forceps, as in the forficula. 
Telifera, armed with a dart or sting, as the panorpa, and scorpion. 
