Species 312
Species 312 was the Borg designation for a race which employed a tetryon-based technology. 

Based on their technology, it was speculated that the species may have been the one that visited the planet Ledos, several hundred years before 2378, and built a tetryon-based energy barrier to protect the primitive Ventu from the harmful actions of the other Ledosians. 

Members of the species were assimilated by the Borg sometime before 2374. ()

cs:Druh 312
de:Spezies 312
it:Specie 312
nl:Ras 312
Species 00312