Svirfneblin:

The svirfneblin, or deep gnomes, dwell in the depths of the earth, where also are found the drow, duergar, and other beings. Unlike the drow and duergar, their society has not split off from that of the surface gnomes; they remain quite friendly, and both speak the Nanomi language. The svirfneblin have been forced by their harsh environment to become somewhat hardier than their surface cousins, but they lack the talents at magery which distinguish surface gnomes. However, as if to compensate, they share with their neighbors the duergar a great predisposition toward psychic abilities, with nearly every svirfneblin developing some form of esoteric mental power in his lifetime.

Svirfneblin generally live for 200 years, and have eyes that are well-adapted to dark conditions but suffer in light.