Spotted leopard slug courtship and exchange of genetic material.

Photo by Robin Rosetta

Another website with a wonderful color diagram of this process with a similar species, Limax cinereoniger, can be found at the link (text is in Czech).

And now, thanks to You Tube, the video of this event.

Beginning courtship

Photo by Robin Rosetta

Reproductive structures emerge

Photo by Robin Rosetta

Reproductive structures enlarge

Photo by Robin Rosetta

Everted reproductive structures

Photo by Robin Rosetta

Intertwining reproductive sturctures

Photo by Robin Rosetta

Flared reproductive structures

Photo by Robin Rosetta