Unidentified myzostomids

Comment from Dr. Richard Willan: The flat, soft-bodied creatures living commensally with the crinoids would be myzostomids. These enigmatic animals are distant relations of bristle worms (Polychaeta), but have a soft body without any external signs of segmentation. Nothing is known about the biology of the Myzostomida, so any observations you can make on their natural history would represent completely new discoveries.