Relative width of the shell, aperture external rim and aperture internal rim.

ANCOVA was used to adjust log(width) to log(length) within each category. Probability values for planned comparisons of adjusted means, together with back-transformed adjusted means and standard errors are tabulated. Labels are as for Table 1. Length  =  back-transformed covariate value used to adjust means. Levene's test: shell shape, P = 0.041, aperture external rim, P = 0.954, aperture internal rim, P = 0.644.