The Gallamite are a species with transparent skulls, visible brains twice the size of a Humans, and toothy smiles. Some had purple skin.
Ambrushroi is a religion practiced by some Gallamites. Their traditions state that a body has to be cremated within six hours. (SCE - Miracle Workers eBook: Invincible, Part Two)
A male Gallamite was an inmate of the prison camp on the planet Pao'la forced to work in that world's dilithium mines. (TOS novel: In the Name of Honor)
Curzon Dax once spent thirteen weeks negotiating with Gallamite delegates on a trade agreement, finding them to be extremely tiresome. When the negotiations were over, Dax took a vacation on Risa as he was exhausted with the experience. (ST - The Lost Era novel: The Art of the Impossible)
Jadzia Dax dated the Gallamite Boday in the early 2370s. (DS9 episodes: "The Maquis, Part II", "Let He Who Is Without Sin...", "Penumbra")
During the Dominion War, the Gallamites supplied duranium to the Federation. (DS9 episode: "Penumbra")
In 2376, a Gallamite delegation was present on Deep Space 9 for Bajor's entry ceremony into the United Federation of Planets. A male Gallamite attended a meeting with Ro Laren where security measures were discussed. (DS9 - Mission Gamma novel: Cathedral)