Abstract
The teeth of the radula of Cipangopaludina Malleata in Hikari City were investigated for number and type of the cusps and other features. The mean values measured were as follows. Central teeth The range of height and width of teeth. H ; 0.19-0.29mm, the mean 0.23mm, W ; 0.20-0.29mm, the mean 0.25mm. The number and the type of the cusps. 7 cusps 3-1-3 type (30%), 9 cusps 4-1-4 type (20%), 10 cusps 5-1-4 type (16%). Inner lateral teeth The range of height and width of teeth. H ; 0.33-0.39mm, the mean 0.34mm, W ; 0.15-0.19mm, the mean 0.17mm. The number and the type of the cusps. 8 cusps 4-1-3 type (51%), 7 cusps 3-1-3 type (34%). Outer lateral teeth The range of height and width of teeth. H ; 0.43-0.45mm, the mean 0.43mm, W ; 0.10mm. The number the type of the cusps. 7 cusps 3-1-3 type (42%), 8 cusps 4-1-3 type (24%), 9 cups 4-1-4 type (19%). Marginal teeth The range of height and width of teeth. H ; 0.45-0.49mm, the mean 0.47mm, W ; 0.10-0.13mm, the mean 0.11mm. The number of the cusps. 8 cusps (58%), 7 cusps (37%). The symmetrical relation of the lateral processes of the cusps of the central and lateral teeth was observed in 64% with the central teeth, in 38% with inner lateral teeth, in 61% with the outer lateral teeth.
