Valve iv profiles. 1: C. septemvalvis H/W 40%, Side slope almost flat.
2: Tonicella marmorea H/W 20% varies to H/W 37%. Side slopes slightly convex to almost flat. 3: Boreochiton ruber H/W 23%. Side slopes moderately convex. 4: Lepidochitona cinerea H/W 32%. Side slopes convex.