| Because of the lack of properly fixed tissue no sections of the enteron of this stage were made. |
| The mouth opens into the main body cavity, or enteron, which connects with radial canals extending to the outer rim of the bell. |
| The layers of its wall are much more fully differentiated than in the more anterior regions of the enteron. |
| The body wall is comprised of two layers of cells separated by a thin, structureless layer of connective tissue called the mesoglea and the enteron, a cavity containing intestinal organs. |
| This structure as has been noted above, is quite distinct from the other parts of the enteron. |
| The cells lining the Wolffian ducts are smaller than those lining the enteron. |
