The complete larval development of a terrestrial crab from West Africa, Cardisoma armatum Herklots, was studied by laboratory cultivation. Six zoeal stages and one megalopa are described and illustrated. Before this study, only an incomplete description of the first zoeal stage of C. armatum has been available (Cannon, 1923), and the complete larval development has been known only from C. carnifex, C. guanhumi and C. hirtipes. In the present paper, the larval morphology of these four congeneric species is compared. Within the Gecarcinidae, the complete larval development has been described also for Gecarcinus lateralis, while only data for the morphology of the first zoeal stage are available for the other two genera of this family, Epigrapsus and Gecarcoidea. Hence, there are at present no sufficient data, in particular on megalopal morphology, to allow for conclusive intergeneric comparison and an identification of familial characters. Gecarcinid zoeal morphology, as far as this is known, is briefly discussed in relation to that in other Grapsoid families.