Thigmotrichida

(invertebrate zoology) An order of ciliated protozoans in the subclass Holotrichia.

A restricted group of forms constituting an order of the Holotrichia and generally found in association with mollusks from both fresh and salt water. Some are mouthless. Those species with a cytostome are generally equipped with a buccal ciliature which indicates an advance over the primitive hymenostome arrangement. See also Holotrichia; Hymenostomatida.