Halgerda terramtuentis is known only from the Hawaiian Islands. This nudibranch is white with a network of gold-orange lines on the dorsum, and a gold-orange line around the mantle edge. The rhinophores and gills are translucent white densely spotted with black. The egg mass is bright yellow in colour.
Similar to t Halgerda malesso, Halgerda batangas,Halgerda carlsoni and Halgerda aurantiomaculata.