Papillae are fleshy projections. Although some papillae are innervated and have a sensory function, they may also aid attachment by acting as a sort of soft spine.
Oral papillae (arrow) are common among allocreadid trematodes, such as Bunodera.
The lateral projections from the side of this Tatria cestode can be considered functionally as papillae.
Rugae are fleshy ridges. Thay roughen the body surface, increasing its grip to the host.
Rugogaster has transverse ventral rugae (arrow).
Gyrocotyle has lateral rugae.
