| Physical deformation of the anus, or infundibuliformity, will often betray members of this class, he remarks. |
| On the upper surface, opposite the mouth, is the periproct, which surrounds the anus. |
| The abdomen bears pleopods, and ends in a telson, which bears the anus, and is often flanked by uropods to form a tail fan. |
| Several months are needed for the larva to complete its development, which begins with the formation of the test plates around the mouth and anus. |
| Scent glands are present below the base of the tail and on the anus. |
