Measuring shells

A large shell may be measured with a ruler, if you look vertically down on it, but for smaller shells vernier calipers are more accurate.

The most accurate method for measuring very small shells is to use a microscope fitted with either a vernier scale on the stage or an eye-piece graticule.

Measure the maximum height and the maximum width in mm.

Before proceeding further, write down the height and width of your specimen.