The Halanans were a telepathic humanoid species native to the planet New Halana. Their telepathy was a form of psychoprojective telepathy.
Halanans had ears somewhat larger than those of a Vulcan, split into two points at the top and bearing a resemblance to those of the Ocampa, but otherwise closely resembled Human ears.
In Halanan culture, one chose a companion for life and would not leave them.
Sometime in the 24th century, the species moved to New Halana, a planet that was terraformed by Gideon Seyetik. (DS9: "Second Sight")
According to StarTrek.com, the Halanans were from the planet Halana. This planet was the namesake for New Halana.