Dala's species were a humanoid race distinguished by a bifurcating (cartilaginous) ridge running vertically down the forehead and stopping at the nose. They were usually bald and were native to the Delta Quadrant.
In the year 2376, three members of Dala's species – Dala, Zar, and Mobar – impersonated the crew of the USS Voyager after they downloaded the computer database of the Delta Flyer. Using the information they gleaned, the three con artists were able to fabricate Starfleet uniforms and bilk unsuspecting races out of goods and services, operating out of their own version of the Delta Flyer.
Dala's species appears to be the same as Species 571.