Abstract:The radular morphology of Cellana toreuma and C.grata was observed by optical microscopy and electron microscopy.Without central tooth,the radular formula of two limpets was "1 ·1 ·0 ·1 ·1",indicating that both had a lateral tooth and a marginal tooth.There was a curve on the firside of radulae where the teeth had loose configuration and had obvious phenomenon of abrasion.The lateral tooth morphology of two limpets was very similar: the lateral tooth was falciform,with a strong cusp,almost triangular base and a protuberance.Part of its cusp was thin.However,there were some differences in tooth morphology between the two limpets: C.toreuma had three strong cusps,with the second close to the third.C.grata had two cusps,with the second cusp close to its base.The base of two limpets was almost triangular and had a protuberance.Seventeen parameters were used to measure the radular band and the teeth on the anterior,middle and posterior segment of radular band for comparison.There was obvious difference in the ratio of length to width of radular strip,indicating that the radular band morphology of C.grata was more thinner.There was a certain relationship between these parameters of three segments of radular band: the ratio of middle segment was greater than that of anterior segment,and the ratio of middle segment was greater than that of posterior segment.It was feasible to use radulae as taxonomic basis of C.toreuma and C.grata.