Ullian
The Ullians were a telepathic  humanoid species native to the Ullian homeworld. ()

History 
Before the 21st century, the Ullians were a violent people. Telepathic memory invasion was a common occurrence. By the end of the 21st century, they had become peaceful, and instances of memory invasion were virtually eliminated, although some members of the Ullian society still practiced that form of rape.

By 2368, the Ullians had embarked upon an ambitious plan to construct a library of memories from species across the Federation and beyond. Several Ullians, including Tarmin and Jev, were trained in telepathic memory retrieval and used the ability to reconstruct and collect memories. It was hoped the memory library would be not unlike an repository of oral histories. One group of Ullians visited eleven planets in eight star systems including Melina II, Nel III, and Hurada III. Kaldra IV was also a planned stop. Before the Ullian delegation arrived at Kaldra IV, Jev was found guilty of committing telepathic memory invasion against several members of the  crew, bringing a temporary interruption to the research. ()

Anatomy and physiology 
The Ullians were physically similar to Humans. The sides of their skulls had a pronounced hairless bulge.

These species of telepaths was unique from other telepathic species  in the sense that they took a vested interest in learning the memories of other species, with the power to enhance and recover lost memories. 

Ullians were capable of telepathically reading most humanoid species, although other telepathic species such as the Betazoids had difficulty in reading Ullian minds. ()

Culture 
For the most part, the Ullians were gentle, honest, and friendly people. They had a great passion for their work, but did not wish to coerce other species into participating if they were not willing.

People

Named
 Inad
 Jev
 Tarmin

Unnamed

Appendices

Background information 
According to the script Ullian was pronounced "YEW-lee-n". On one viewscreen, the species name was spelled as "Ulian". 

Their physical appearance was not described in the script notes. Keeping that in mind, as according to Michael Westmore:
As I started thinking about ideas for the Ullians, the race of telepathic humanoids introduced in "Violations," I wanted to do something a little different with them. Instead of creating some sort of forehead appliance, I decided to work with the temporal area at the side of the head. The makeup we created looks like a pattern of suction cups, which were bigger for the men and slightly smaller for the woman. We also added more lines and wrinkles for the older characters, suggesting that the temporal patterns change as they get older. 

Once the appliances had been glued to the side of the head, we took hair and laid it over the upper edge of the pieces, so it looked as though the pattern was a normal part of the skin, and their hair would naturally grow over it. I thought it was a very subtle makeup that worked very effectively without drawing too much attention to itself. (Star Trek: The Next Generation Makeup FX Journal, p. 88)

The internal reference document, listing all the aliens seen in  up through TNG Season 5, described the Ullians as a "humanoid race, distinguished in appearance by lightly upswept eyebrows and a rough-textured membrane that covers the top of the ear and melds flush to the head. Some are telepathic."

Apocrypha 
According to the DS9 comic "Requiem in Obsidian", the Obsidian Order used Ullians as agents.

External link

de:Ullianer
ja:ユリアン
Species
Telepathic species