In this paper we study symmetry reductions of a class of nonlinear third order partial differential equationswhere ǫ, κ, α and β are arbitrary constants. Three special cases of equation (1) have appeared in the literature, up to some rescalings. In each case the equation has admitted unusual travelling wave solutions: the Fornberg-Whitham equation, for the parameters ǫ = 1, α = −1, β = 3 and κ = 1 2 , admits a wave of greatest height, as a peaked limiting form of the travelling wave solution; the Rosenau-Hyman equation, for the parameters ǫ = 0, α = 1, β = 3 and κ = 0, admits a "compacton" solitary wave solution; and the Fuchssteiner-Fokas-Camassa-Holm equation, for the parameters ǫ = 1, α = −3 and β = 2, has a "peakon" solitary wave solution.A catalogue of symmetry reductions for equation (1) is obtained using the classical Lie method and the nonclassical method due to Bluman and Cole.