AbstractA collection of Middle Viséan nantiloids from the Isle of Man is described, together with two specimens from beds probably of the same age in Derbyshire. The generaVestinautilusde Ryckholt,StrobocerasHyatt, andDomatocerasHyatt are more closely defined on the basis of their type‐species, and the opportunity is taken to refigure the types ofStroboceras hartti(Dawson) andDomatoceras umbilicatumHyatt. The types ofOrthoceras gesneriPhillips (nonFleming) andNautil is bistrialisPhillips are also refigured and described. With the stricter definition of genera adopted in this paper several new genera and species are necessary to receive the specimens described, and the familyTemnocheilidae Mojsisovicsis revived for,inter alia. TemnocheilusMcCoy andKnightocerasMiller and Ow