[2]

Τρῆμα, a hole; referring to the orifices of the suckers.

[3]

Mémoires pour servir à l'histoire d. Polypes d'eau douce, Leyden, 1744.

[4]

Die Parasiten des Menschen, 1879——. Engl. Transl. by W. E. Hoyle, i. 1886.

[5]

Band 4, by M. Braun. (Mesozoa and Trematoda completed; Cestoda in progress.)

[6]

Verm. terr. et fluv. ... succincta historia, 1773; Zool. Danica, 1777.