p2
Two-fold rotations only. Centers in four different locations.
From Kathy Paur:
![p2-1](p2-kp1.jpg)
![p2-2](p2-kp2.jpg)
From Simon Gregg:
p2mm
Perpendicular mirrors.
Two-fold rotations with centers in four different locations.
From Kathy Paur:
![p2mm-1](p2mm-1.jpg)
![p2mm-2](p2mm-2.jpg)
p2mg
Mirrors perpendicular to glide reflections.
Two-fold rotations with centers in two different locations.
p2gg
Perpendicular glide reflections.
Two-fold rotations with centers in three different locations.
c2mm
Perpendicular mirrors.
Perpendicular glide reflections.
Two-fold rotations with centers in three different locations.
![c2mm-1](c2mm-1.jpeg)
From Kathy Paur:
![c2mm-2](c2mm-2.jpg)