ClipArt ETC
"Diagrams of some principal forms of tails in fishes. A, protocercal fin (as in Polypterus); B, heterocercal (as in Sharks); C, homocercal (as in most Teleosts); D, homocercal (as in Amia)." -Galloway, 1915

Fishtails

"Diagrams of some principal forms of tails in fishes. A, protocercal fin (as in Polypterus); B, heterocercal…