| In the Middle and Late Silurian odd specializations, like lacunose septa and complex septal formations in the body chamber, develop. |
| Where there is some uncertainty about how a partially lacunose word should be restored, the uncertain letters are placed within brackets. |
| Aside from the loss of the first thirteen books, the remaining eighteen are in many places corrupt and lacunose. |
| In such specimens it will be seen that the hymenium has become highly convoluted or lacunose. |
