This is the third of three volumes of Keys to the Trematoda, a series on the systematics and identification of the Class Trematoda.

Contributions by: Vasyl V Tkach, Tomas Scholz, C P Santos, S E Pozdnyakov, T Pojmañska, John Pearson, Terrence L Miller, R Madhavi, Jeffrey M Lotz, William Font, Stephane Deblock, Thomas H Cribb, Ronald A Campbell, David Blair, Diane P Barton