Galdus Mon was a Yridian individual.

In 2385, Mon attempted to contact Lenkit Casten on Endalla, but did not know that she had died five years earlier. When Mon was questioned by Ernak gov Ansarg on why he had tried to contact Lenkit on Endalla, Mon mentioned that he had met Lenkit through his fine art dealings, Lenkit having bought a Lorillian sculpture from Mon several years before her death. (DS9 novel: Sacraments of Fire)