The parasite that's doing the damage is a flatworm, a trematode called Hepatodirus hominis.
The trematode parasites from a collection of amphibians and reptiles.
Bilharzia, bil′hr-zi-a, n. a human parasitic flat worm in the fluke or trematode order, with differentiated sexes.
Distomum, a genus of trematode or suctorial parasitic worms or flukes, infesting various parts in different animals.
I need hardly add that Dr Johnson had from the very first recognised the trematode character of the parasites.
In 1802 Bosc described and figured a trematode under the title of Fasciola fusca.
Gap′er; Gapes, a disease of birds, owing to the presence of trematode worms in the windpipe, shown by their uneasy gaping.
The closest relatives of that trematode (also recorded from T. ferox) live in marine turtles.
It wouldn't be simple, because this trematode was probably Hepatodirus hominis, and it was tricky.
trematode trem·a·tode (trěm'ə-tōd')
Any of numerous flatworms of the class Trematoda. Also called fluke1.
Any of numerous parasitic flatworms of the class Trematoda, having a thick outer cuticle and one or more suckers or hooks for attaching to host tissue. Flatworms include both external and internal parasites of animal hosts, and some cause diseases of humans in tropical regions, such as schistosomiasis. Liver flukes, blood flukes, and planarians are flatworms. Also called fluke.