CLADOENDESIS OF EPHEMEROPTERA
Figure 10. Copulation.
A–F – Tibia-tarsal articulation of male fore leg of Metretopus/fg* borealis [Heptagenia] (each leg lies with knee articulation directed up and tarsus directed to the right); left figures (A, C, E) – left leg in median view; right figures (B, D, F) – right leg in lateral view: A–B – subimago; C–D – imago with normal position of tarsus (arrow shows future rotation which leads to position on Figs E and F); E–F – imago with tarsus turned around at 180˚. G–H – Pose of copulation of Parameletus/fg2 chelifer [Parameletus] (from Kluge 2000 based on Brinck 1957).