I am looking for a good image of Polystoma integerrimum (Polyopisthocotylea: Polystomatidae) for a new book I'm working on. If anyone knows of a source, I'd appreciate the information. In the 1950s someone by the name of Joan B. Williams is supposed to have produced good drawings at the London School of Hygiene and Tropical Medicine but I haven't been able to locate them.
The genus is supposed to have been mistakenly so named because an early investigator (presumably in the eighteenth century) mistook the six posterior suckers which form the ophisthaptor as mouths. This seems plausible enough but I haven't yet succeeded in tracking down this story. Again, any help would be appreciated.