Records of parasitic worms from British marine fishes are still rather scanty. A good deal of attention has been paid to the subject of the Trernatodes by Nicoll, whose valuable list (1915) is indispensable to anyone working in this field. Nicoll is himself responsible for the records of the majority of the 49 species of Trematodes given in the second edition (1931) of the “Plymouth Marine Fauna.” The only work done on the Cestodes of fishes at Plymouth appears to have been that of Woodland (1927, a and b), as a result of which 14 species have been placed on record. Very few data are available as to the Nematodes, and none as to the Acanthocephala, of the Plymouth fauna.