| The top layer is called the epidermis, and the inner layer is referred to as gastrodermis, which lines the gut. |
| The inner surface of the cavity is lined with an epithelium, the gastrodermis. |
| In other parts of the canal system, the gastrodermis is different on the sides nearest to and furthest from the organ that it supplies. |
| Other mesodermal cells in the acoels are the peripheral parenchyma and tunica cells of the gonads, and these also arise from the gastrodermis. |
| Sea anemones have all of the muscle fibres in the gastrodermis, though some of the fibres are longitudinal and some are circular. |
