Telepathic humanoids whose historians collect the memories of other peoples, one of whom used his abilities to assault members of the Enterprise crew.
The Ullians are a telepathic humanoid species whose historians travel to other worlds to gather memories. They retrieve these through a guided telepathic probe and preserve them as an archive of the experiences of many peoples.
In Violations, an Ullian delegation of Tarmin, his son Jev and Inad visited the Enterprise. Several crew members, including Deanna Troi, Riker and Beverly Crusher, fell into comas after experiencing intrusive memories. Investigation revealed that Jev had been using his telepathy to assault people's minds, a crime he had committed on other worlds, and he was taken into custody.