The Marijne VII subspace beings were a non-corporeal species inhabiting the lower atmosphere of the gas giant Marijne VII. In their natural form, they appeared as floating plumes of fire.
In 2370, members of this species attempted to communicate with the crew of the Federation starship USS Raman, but the process accidentally caused the deaths of all seven crew members. The beings were then trapped aboard the Raman in the planet's upper atmosphere, where they could not long survive.
When the USS Enterprise-D arrived to investigate the fate of the Raman, Lieutenant Commander Geordi La Forge encountered one of the beings through the interface probe. Reading La Forge's mind, the being masqueraded as his missing mother Silva La Forge to convince him to bring the Raman closer to the surface, so that it and the others of its kind could escape. It eventually revealed its true nature to La Forge, who helped to release them from the ship. (TNG: "Interface")