Summary.An attempt has been made to present a full account of the anatomy of the head (exclusive of the inner ear) ofLeiopelma.Material from two species,Leiopelma archeyiandLeiopelma hochstetteri, has been studied and the head of the latter is here described for the first time.As far as possible, comparison has been made with the head ofAscaphus, the only other genus included in the same primitive anuran family.Specific differences betweenLeiopelma archeyiandLeiopelma hochstetteriare described and listed.A possible homology is suggested between the processus lingularis of Anura and Seydel's palatal process of Urodela.Particular emphasis is placed on the controversial topic of the basal connection between the quadrate and the neurocranium. An historical account of previous ideas on this subject is included, followed by a discussion based on the view that the ‘basal’ or ‘pseudobasal’ process ofLeiopelma, together with the ledge of cartilage forming the floor of the hyomandibular canal, are of hyoid